# Alternative heat source, minisplits for real?



## Highbeam

So we had another one of our random burn bans yesterday so I was unable to burn my stove despite air quality in the green "good" for my area. I hate the bans because I think they are not compliant with the law but I took this opportunity to do some checking on my home's systems.

It was 25 degrees F last night. Even down into the single digits I am consistently burning under 60# of wood per day to keep the joint very warm inside. If I conservatively assume 80% actual efficiency that means on average 17,200 btu per hour. Seems low I thought. Heck that's just 5000 watts. It is very rare that we get below 20 degrees in my location. 95% of the year I burn just 40# a day (a single load of softwood) which comes out to 11500 btu per hour.

My "primary" heat source is a whole bunch of electric resistance wall heaters. This old house has never had ducts or radiators. It has a bunch of 20 amp, 240 volt, 12 gauge circuits that feed these wall heaters. I've replaced 2 of them during remodeling with pick-a-watt 2250 watt units. There is one of these circuits that is unused as I haven't found a good place to put the heater.

Due to the burn bans I had a chance to test them. I flipped two of the breakers on for the first time in a decade and really should have blown them out first. The dust stinks! Those two heaters in the main living area held 70 degrees and only cycled about 50% of the time so I was actually holding 70 with just 8000 btu per hour.

I have always liked the Mitsubishi hyperheat minisplits but the inside unit is uglier than my princess stove! The 18kbtu model inside unit is just 38" wide and apparently would be enough for 100% of my heating. It's supposed to make 20,000 btu per hour of heat down to 5 degrees. All from a silly small 15 amp circuit. Plus AC and I would keep the old wall heaters as backup backups. I just can't imagine running ductwork in this single story home. It would all be in the attic.

Is this correct? Did I miss anything in my heat load testing theory? Does the circuit for these things need to be a 4 wire 12/3 circuit? The specs say it needs 15 amps but do you oversize the circuits 20% for minisplits with like a 20 amp breaker and 12 gauge wire?


----------



## Tegbert

I’ve been looking at adding some to my house too. I’m Leary of what some people say that they can heat/cool a large area with one head unit. I have even been told that by most installers that we wouldn’t notice much heating or cooling down to our bedrooms. 

Most of the ones I have seen are on the verge of 12 gauge wire size so I assume 10 would be the way to go. But that was for 3-4 ton units. Also the ones I have looked at are only 3 wire. Two hots and and a ground. I’m not sure why the neutral is not needed. 

Also they do have ceiling cassette ones if your roof trusses are 22” plus on center. That way you could put it centrally in the room and not have a box on the wall. 

Not much help on the load calculation as I’m trying to figure out the same thing myself. 


Lopi Rockport
Blaze King Ashford 25


----------



## Highbeam

Tegbert said:


> I’ve been looking at adding some to my house too. I’m Leary of what some people say that they can heat/cool a large area with one head unit. I have even been told that by most installers that we wouldn’t notice much heating or cooling down to our bedrooms.
> 
> Most of the ones I have seen are on the verge of 12 gauge wire size so I assume 10 would be the way to go. But that was for 3-4 ton units. Also the ones I have looked at are only 3 wire. Two hots and and a ground. I’m not sure why the neutral is not needed.
> 
> Also they do have ceiling cassette ones if your roof trusses are 22” plus on center. That way you could put it centrally in the room and not have a box on the wall.
> 
> Not much help on the load calculation as I’m trying to figure out the same thing myself.
> 
> 
> Lopi Rockport
> Blaze King Ashford 25



Thanks Teg.

If my stove can heat the whole home from the stove room then I figure putting the minisplit head in the stove room would do the same thing. We are quite happy with the slight, 5-10 degree at most, variation in temperature from stove room to bedroom. HVAC nerds will say that this is "low" comfort but I love it.

If I'm running a new wire to that existing breaker I may as well use 10/3 and just not use the neutral at the disconnect. Perhaps a future device will want that neutral. I could also underbreaker the 10 gauge at 20 if that is what the equipment calls out.

The ceiling cassettes are also pretty ugly, even worse than the wall units in that they resemble an RV air conditioner and the wife doesn't want to live in a trailer! Those cassettes also usually have a condensate pump built in and they carry a large efficiency penalty.

These things are several thousand dollars. 2-3 for the unit and then who knows how much for install. I hate hiring people but this skillset is very unique.


----------



## Tegbert

I hear you about the install prices. I have had three quotes for 3 zones at about 13-14,000. I had another quote for 5 zones and just under 15,000 but that in my opinion is too much for my house. 




Lopi Rockport
Blaze King Ashford 25


----------



## Highbeam

Tegbert said:


> I hear you about the install prices. I have had three quotes for 3 zones at about 13-14,000. I had another quote for 5 zones and just under 15,000 but that in my opinion is too much for my house.
> 
> 
> 
> 
> Lopi Rockport
> Blaze King Ashford 25



Whoa, that's high. A single zone, single head unit should be much cheaper. If not, well, that will pay for a lot of resistance heating!


----------



## SpaceBus

I have resistance heaters and I am planning on getting one or two mini splits. The house came with 70's Merkel electric resistance baseboard heaters, but they are very expensive to run. They work very well, but power is too expensive here. There have been times when we need to leave for an extended period and   can't run the stove, this means baseboards are on. Having AC sounds nice too, but I doubt we will ever need it. I agree with you on how they look, but most efficient things don't look nice, in the traditional sense anyway.

My stay in Afghanistan was heated exclusively by cheap Chinese knock off mini splits called Chigos. These worked extremely well, except for mine which didn't defrost. I'm not sure if any did, but it would wake me up in the middle of the night when the fan blades hit the ice. Despite having to chisel out the ice occasionally, I stayed warm. Temps were regularly single digits f. I am a believer.


----------



## Tegbert

Highbeam said:


> Whoa, that's high. A single zone, single head unit should be much cheaper. If not, well, that will pay for a lot of resistance heating!



Should be much cheaper hopefully. But that is why I probably will be doing it all myself I can’t see spending 15k on something I won’t see any savings by installing it as we heat with wood like you so it would be used to heat while we are gone for long periods of time or when I’m lazy and don’t want a fire so my electric bill will be higher. It might be cheaper in the summer as we usually run two to three portable AC units though. 


Lopi Rockport
Blaze King Ashford 25


----------



## Highbeam

Our power in this area is still right near 10 cents per KWH. So last night it was costing me 22.5 cents an hour to heat the place. Say 6$ per day. With a 144$ dollar wall heater that requires no maintenance. Dang it.

I'm going to try heating the place again tonight with just electric resistance heat to verify the numbers. Seems too low.


----------



## SpaceBus

Highbeam said:


> Our power in this area is still right near 10 cents per KWH. So last night it was costing me 22.5 cents an hour to heat the place. Say 6$ per day. With a 144$ dollar wall heater that requires no maintenance. Dang it.
> 
> I'm going to try heating the place again tonight with just electric resistance heat to verify the numbers. Seems too low.



In my case it's the power company that is the issue. The service/delivery fees are as much as my power usage fees.


----------



## Highbeam

SpaceBus said:


> In my case it's the power company that is the issue. The service/delivery fees are as much as my power usage fees.



Our 10 cents is all in. Total bill divided by kwh used. I have heard of folks paying three times as much and at that rate there is more money to invest in these ultra high efficiency devices. Your payback period falls quickly! Also, solar even becomes a reasonable investment.


----------



## SpaceBus

Highbeam said:


> Our 10 cents is all in. Total bill divided by kwh used. I have heard of folks paying three times as much and at that rate there is more money to invest in these ultra high efficiency devices. Your payback period falls quickly! Also, solar even becomes a reasonable investment.



I very much so would like solar, but other things come first.


----------



## Brian26

I am about to install one myself. After doing a ton of research they really are not hard to install at all. All you really need for specialized tools is a vacuum pump  and micron gauge. The actual pipe connections is just 4 flare fittings. The condenser is precharged with the exact amount of refrigerant for up to 15 ft on lineset. These are installed by the millions all over the world by simply pulling a vacuum and opening the valve and letting refrigerant flow. 

From my research almost all of the units are made by Gree with whatever brand sticker on them. Pioneer, Senville, blueridge, mr cool, etc. They all have pretty much the exact same manuals, remotes, etc. Gree is the largest air conditioner manufacturer in the world. Yeah its made in China but so are the other name brand units. 

I ended up going with the Pioneer unit for $800 delivered to my house with everything included to install it. Its a cold weather/hyper heat model and provides full heat output to 5 degrees. It cuts out at -13  and Its certified by the American AHRI rating organization so they actually tested in the lab. From my research the Pioneer units have the best warranty and reviews online. Its the #1 seller on Amazon. I had to wait a month just to order it as the company that distributes them in Miami said they were selling them like crazy and waiting for more to arrive by ship. 

If you have an HVAC company come out your looking at $4-5K for a Mitsubishi or Fujitsu. Yes they are the best and you get 12 year warranties but for $800 I can buy 5 Pioneers.


----------



## Brian26

Highbeam said:


> Our 10 cents is all in. Total bill divided by kwh used. I have heard of folks paying three times as much and at that rate there is more money to invest in these ultra high efficiency devices. Your payback period falls quickly! Also, solar even becomes a reasonable investment.



According to the EIA Washington has some of the cheapest prices at 9.68 cents a kwh. I have heard its from all that hydro power there? Its way cheaper than even all the coal states like Wyoming. 

https://www.eia.gov/electricity/monthly/epm_table_grapher.php?t=epmt_5_6_a

I installed solar 2 years ago but the electricity here in CT was almost 3 times that last I checked with all the fees and stuff. Solar was a no brainier here with those prices. Actually I just checked in its right behind Alaska at the highest in the US with Hawaii being number one. 

My neighbor converted from electric heat to Mitsubishi mini splits and literally saved like a few thousand in the first year he said. He said his father converted in the 70s when it was cheaper to run electric heat. Some of the newer Fujitsu units have Coeffecient of performance near 4.5 now. Meaning they are 450% more efficient than regular electric heat. They are putting out an incredible amount of heat with very little power used. Some of them have cooling ratings of 33 seer now. I believe window ac's are around 8 seer so they use about 4 times less power cooling as well.


----------



## Highbeam

Brian26 said:


> According to the EIA Washington has some of the cheapest prices at 9.68 cents a kwh. I have heard its from all that hydro power there? Its way cheaper than even all the coal states like Wyoming.
> 
> https://www.eia.gov/electricity/monthly/epm_table_grapher.php?t=epmt_5_6_a
> 
> I installed solar 2 years ago but the electricity here in CT was almost 3 times that last I checked with all the fees and stuff. Solar was a no brainier here with those prices. Actually I just checked in its right behind Alaska at the highest in the US with Hawaii being number one.
> 
> My neighbor converted from electric heat to Mitsubishi mini splits and literally saved like a few thousand in the first year he said. He said his father converted in the 70s when it was cheaper to run electric heat. Some of the newer Fujitsu units have Coeffecient of performance near 4.5 now. Meaning they are 450% more efficient than regular electric heat. They are putting out an incredible amount of heat with very little power used. Some of them have cooling ratings of 33 seer now. I believe window ac's are around 8 seer so they use about 4 times less power cooling as well.



I was surprised to see that 38% of my power is from coal. Our western Washington power is double to triple the cost of those eastern Washington cities near the power production dams. It’s basically free!

The cop of 4 means you get 3 for free. Electric resistance has a cop of 1. Pretty great but as a backup to wood heat or even using it half time with this cheap power I would expect decades to recover the cost of the equipment.


----------



## Highbeam

Another night in the 20s. I logged 55 additional kwhs over 24 hours by running resistance heat instead of wood heat. That again checks out to under 8000 btu per hour! I guess my insulation is pretty good when keeping the house just under 70. So 5.50$ in extra energy costs per day of electric resistance heat which is not as high as I would have thought.

If the minisplit cost 5000$ to install and cuts my resistance heat consumption by 66% (assuming a COP of 3), then I would only have paid 1.82$ so a savings of 3.68$ per day of use. It would take 1,358 winter days of use to cover the installation cost. If I was a non-woodburner and needed to heat on average 180 days per year then the thing would have a 7.5 year break even point. That's not bad if wood heat was flat out banned forever. The equipment should last 10 years. I made an assumption above of 180 days of heat but we really need less heat for a longer time in the shoulder seasons. I also believe that the COP of 3 is rather optimistic when it is below freezing but pretty close on average.

That last 2.5 years for free only adds up to a reward of 662 bucks. Will I even live here for 10 years? Will it even last for 10 years? Will there be a better technology in 10 years?

Since I do heat with wood. The only benefit is the 7 days a year or so that burning is banned where the savings would be 25.76$ per year. It would take 194 years to break even.

I am not going to install the minisplit. They are just too expensive to make financial sense in my situation due to small heating load and cheap power. Resistance heat for the win!


----------



## begreen

Good economic analysis. There are times when a mini-split makes sense for some and times when it doesn't. If one wanted AC too, then it would start to make a bit more sense perhaps. For us the decision was easier as we were replacing a god-awful expensive propane system. Unfortunately mini-splits and inverter compressor systems were not available locally at that time so we went for a high-end 2 stage central hvac instead. No regrets. The only thing we've done in 12 yrs is replace the filters and the operating cost is peanuts, less that the cost of wood and a lot cleaner.


----------



## SpaceBus

Highbeam said:


> Another night in the 20s. I logged 55 additional kwhs over 24 hours by running resistance heat instead of wood heat. That again checks out to under 8000 btu per hour! I guess my insulation is pretty good when keeping the house just under 70. So 5.50$ in extra energy costs per day of electric resistance heat which is not as high as I would have thought.
> 
> If the minisplit cost 5000$ to install and cuts my resistance heat consumption by 66% (assuming a COP of 3), then I would only have paid 1.82$ so a savings of 3.68$ per day of use. It would take 1,358 winter days of use to cover the installation cost. If I was a non-woodburner and needed to heat on average 180 days per year then the thing would have a 7.5 year break even point. That's not bad if wood heat was flat out banned forever. The equipment should last 10 years. I made an assumption above of 180 days of heat but we really need less heat for a longer time in the shoulder seasons. I also believe that the COP of 3 is rather optimistic when it is below freezing but pretty close on average.
> 
> That last 2.5 years for free only adds up to a reward of 662 bucks. Will I even live here for 10 years? Will it even last for 10 years? Will there be a better technology in 10 years?
> 
> Since I do heat with wood. The only benefit is the 7 days a year or so that burning is banned where the savings would be 25.76$ per year. It would take 194 years to break even.
> 
> I am not going to install the minisplit. They are just too expensive to make financial sense in my situation due to small heating load and cheap power. Resistance heat for the win!



I don't blame you, it's radiant heat. Resistance heaters work well. We bought our house to retire in, so it makes more sense for us. Our state also offers a rebate on mini splits.


----------



## peakbagger

My installed (DIY) cost for a 12,000 Btu unit was around $2,700. The non economic paybacks were more important; the ability to skip running my boiler for about 4 months a year during shoulder seasons and the ability to head out for an extended period when my storage runs out during much of the heating season. Plus I get some AC for free.


----------



## Highbeam

begreen said:


> Good economic analysis. There are times when a mini-split makes sense for some and times when it doesn't. If you wanted AC too, then it would start to make a bit more sense perhaps. For us the decision was easier as we were replacing a god-awful expensive propane system. Unfortunately mini-splits and inverter compressor systems were not available locally at that time so we went for a high-end 2 stage central hvac instead. No regrets. The only thing we've done in 12 yrs is replace the filters and the operating cost is peanuts, less that the cost of wood and a lot cleaner.



I believe that a reasonably efficient central HVAC system adds value to the home so if I had ducts then I would be installing some type of central furnace system but I do not believe that these minisplit systems have gained enough acceptance to be a value adder to a home sale over baseboard heat. That is, unless you are an HVAC nerd and the equipment is top notch.

I'm also not convinced that your 2 stage system was a bad way to go. The increase in efficiency for variable compressors and evaporators would likely not have been enough to pay for the added equipment costs over its life given your wood heat supplement and our cheap electricity. There is a lot to be said for simple, cheap, low seer, single stage heat pumps. Soon they will steal enough technology to be able to make full output in cold temperatures without the strip heat.


----------



## Highbeam

peakbagger said:


> My installed (DIY) cost for a 12,000 Btu unit was around $2,700. The non economic paybacks were more important; the ability to skip running my boiler for about 4 months a year during shoulder seasons and the ability to head out for an extended period when my storage runs out during much of the heating season. Plus I get some AC for free.



Thanks Peak, the self install saved you a ton! Installing cheap baseboard electric heaters (or if they are existing) also would have allowed you to head out for an extended period too.

Luckily we don't need AC. If it was a need in this area, there would have already been ducts and a conventional split system would be the logical way to go.

With solar, and high cost electricity, the economics might be a bit different.


----------



## Dobish

we are looking at some options for our house too, and I was contemplating a mini split for the upstairs. Right now the stove does most of the wood, but in the summer it is brutal without AC (which we do not have). Our basement stays pretty cool in the summer, and without the stove is freezing in the winter. We didn't burn for a couple of days and our basement stayed around 56º. I could tell that our furnace was kicking in, but it wasn't bringing the temp up down there. 

We are putting in radiant heat cove heaters in our new garage build, and I have been in a few places that have them. the heat just feels really nice in there.  We were thinking about adding a few to our bedrooms/downstairs living room with a separate thermostat at some point. I think we are going to wait and see what the electric bill comes in at.


----------



## begreen

Highbeam said:


> I believe that a reasonably efficient central HVAC system adds value to the home so if I had ducts then I would be installing some type of central furnace system but I do not believe that these minisplit systems have gained enough acceptance to be a value adder to a home sale over baseboard heat. That is, unless you are an HVAC nerd and the equipment is top notch.
> 
> I'm also not convinced that your 2 stage system was a bad way to go. The increase in efficiency for variable compressors and evaporators would likely not have been enough to pay for the added equipment costs over its life given your wood heat supplement and our cheap electricity. There is a lot to be said for simple, cheap, low seer, single stage heat pumps. Soon they will steal enough technology to be able to make full output in cold temperatures without the strip heat.


When we bought our system there were no single-stage system with good HSPF. I haven't checked to see if this has changed, but I suspect not. Usually the best performers are the premium systems. It's not all about payback. There are other benefits to multistage units. One major one is quietness, another is reduced electrical consumption. We're in it for the long haul. Like our solar setup, payback periods of 6+ yrs are ok. With a $3000+  wood & propane bill (and climbing) compared to now the heating system upgrade paid for itself pretty quickly.


----------



## Highbeam

That’s key, you had a 3000$ heating bill. That large (for this area) bill provides the potential for savings. Savings that pay for improvements within a reasonable period of time.


----------



## begreen

Yes, propane is ridiculously expensive in our area. Captive market. It's the worst fuel for heating here. And our house is old with too much glazing. Crazy as this may seem, the cost of propane went up quite a bit more after we got the new system! We don't miss it at all. Our annual heating bills including wood purchased dropped down to the $500-700 range by the next winter depending on how much wood I scrounged up vs buying.


----------



## woodgeek

I've done similar BTU load tests when my HP compressor failed 4 years ago and I was running resistance backup.

I am sure your BTU figures are within 10%.   A few separate minor factors....
1. Wind increases BTU load in a highly non-linear way.  
2. BTU loads from stack effect air leakage are quadratic in Delta-T, not linear.
3. BTU loads on unusually cold nights are lower than expected from a linear model Delta T due to thermal buffering by the ground on the foundation. 
If your wind was low, 2 and 3 probably canceled each other out.

Sounds like a minisplit is a no-brainer in terms of functionality (assuming you want an AC).  Its more about comfort than $$, and then it s a personal decision, not an economic one.

As for the ugly....I suspect that after a few weeks you will cease to notice it at all.


----------



## Brian26

Just finished up installing my cheap Chinese mini split. It was an 18k 110v unit that cost me $798. Install really wasn't that bad. I had most of the tools already just had to buy a micron gauge, valve core removal tool and vacuum rated line. Total cost was about $200 for the specialized tools.

Will be interesting to see how it performs the next few days. Its currently 34 here now but temps are going to plummet tomorrow after the storm we are about to get. Looks like some of the coldest air of the season is coming in with a low of 3 forecasted Sun Night and 12 on Monday. Its a ultra low ambient temperature model that claims full heat output to 5 and it cuts out at -13. I will say though that this thing is pumping out incredible heat right now with temps in the 30's out. I have a whole house electricity monitor and at full speed it only uses about 900 watts and mostly  runs at a fraction of that.


----------



## begreen

Looks good. The next couple days will definitely be a test. Is this a Pioneer? What model is this? I only see 12,000 and 9,000 btu units in 115v.


----------



## Brian26

begreen said:


> Looks good. The next couple days will definitely be a test. Is this a Pioneer? What model is this? I only see 12,000 and 9,000 btu units in 115v.



It was a Pioneer. This is the one I bought.  Though the HSPF is actually 11.2. For some reason the 115v has a better HSPF and the 220 has a 10.5 rating? This is going off the AHRI rating where they actually test them in a lab.

https://www.highseer.com/ultra-high...ductless-mini-split-heat-pump-wys012am22.html


----------



## begreen

Ah, ok. That is the high heat 12,000BTU unit. Great deal and it would be easy to run on a generator.


----------



## Brian26

begreen said:


> Ah, ok. That is the high heat 12,000BTU unit. Great deal and it would be easy to run on a generator.



My mistake you are correct it is a 12k unit. I was going to go with the 18k but I liked the fact I could easily run it off my generator as the 12k is only 120 volts At full output it uses about 900 watts. I also read that sizing is not important as these units can regulate their output. I have been monitoring the electricity usage of mine and it seems to barely run at its full output. I am blown away by how little power it uses and the heat it puts out.

Though we are getting freezing rain here now and it seems to be defrosting about once an hour. Though the defrost cycle uses little energy. I think it just reverses the refrigerant cycle to melt to outside coils.

I think heat pumps are going to be the way to go in the future for heat. The efficiency is only going to get better. Mitsubishi and Fujistsu have units now that produce incredible heat at low temps.

I installed a 5.4kw solar system 3 years ago and have had extra kwhs every year that I sell back at wholesale prices for pennies. This unit is basically free to run for me. I am beyond impressed and am looking into installing another one.


----------



## DBoon

Brian26 said:


> I think heat pumps are going to be the way to go in the future for heat. The efficiency is only going to get better. Mitsubishi and Fujistsu have units now that produce incredible heat at low temps.


Yeah, I remember that 5 years ago I thought all heat pumps were as crappy as the big outdoor ducted units that I've been subjected to my entire life. The ductless mini-splits are a totally different animal. I am completely sold on them and totally impressed by their performance as well. The only problem is the turn-off from having to deal with the installers who quote ridiculous prices for them - 100% markups or more on a $1500 heat pump to run an eight foot refrigerant line up an outside wall and directly into a head unit. If that install cost problem gets solved, these things will proliferate like crazy.


----------



## Highbeam

Central split systems have benefited from the technology advances as well. Particularly the cold weather performance which was a problem.

So self installing isn’t magical or bizarrely difficult?


----------



## Ashful

Highbeam said:


> So we had another one of our random burn bans yesterday so I was unable to burn my stove despite air quality in the green "good" for my area. I hate the bans because I think they are not compliant with the law but I took this opportunity to do some checking on my home's systems.
> 
> It was 25 degrees F last night. Even down into the single digits I am consistently burning under 60# of wood per day to keep the joint very warm inside. If I conservatively assume 80% actual efficiency that means on average 17,200 btu per hour. Seems low I thought. Heck that's just 5000 watts. It is very rare that we get below 20 degrees in my location. 95% of the year I burn just 40# a day (a single load of softwood) which comes out to 11500 btu per hour.
> 
> My "primary" heat source is a whole bunch of electric resistance wall heaters. This old house has never had ducts or radiators. It has a bunch of 20 amp, 240 volt, 12 gauge circuits that feed these wall heaters. I've replaced 2 of them during remodeling with pick-a-watt 2250 watt units. There is one of these circuits that is unused as I haven't found a good place to put the heater.
> 
> Due to the burn bans I had a chance to test them. I flipped two of the breakers on for the first time in a decade and really should have blown them out first. The dust stinks! Those two heaters in the main living area held 70 degrees and only cycled about 50% of the time so I was actually holding 70 with just 8000 btu per hour.
> 
> I have always liked the Mitsubishi hyperheat minisplits but the inside unit is uglier than my princess stove! The 18kbtu model inside unit is just 38" wide and apparently would be enough for 100% of my heating. It's supposed to make 20,000 btu per hour of heat down to 5 degrees. All from a silly small 15 amp circuit. Plus AC and I would keep the old wall heaters as backup backups. I just can't imagine running ductwork in this single story home. It would all be in the attic.
> 
> Is this correct? Did I miss anything in my heat load testing theory? Does the circuit for these things need to be a 4 wire 12/3 circuit? The specs say it needs 15 amps but do you oversize the circuits 20% for minisplits with like a 20 amp breaker and 12 gauge wire?



Way late to this thread, and I didn’t read the responses, but I do have three minisplits.  They are fantastic in what I believe are your typical winter temperatures, above maybe 20 or 25F.  However, when temps dip into the teens, they really struggle to keep up, and they burn a ton of electrons.  If you have electric resistive, the minisplits might be a great addition, given your climate.  Run the minisplits down to maybe 25F, then switch over to the resistive.


----------



## Highbeam

Ashful said:


> Way late to this thread, and I didn’t read the responses, but I do have three minisplits.  They are fantastic in what I believe are your typical winter temperatures, above maybe 20 or 25F.  However, when temps dip into the teens, they really struggle to keep up, and they burn a ton of electrons.  If you have electric resistive, the minisplits might be a great addition, given your climate.  Run the minisplits down to maybe 25F, then switch over to the resistive.



You’re right about our climate temperatures and even better is that when it’s cold it is usually also very low winds. We occasionally dip into the single digits but not often and not for extended time. 

If I were to install a heat pump I would keep the resistance heaters.


----------



## SpaceBus

DBoon said:


> Yeah, I remember that 5 years ago I thought all heat pumps were as crappy as the big outdoor ducted units that I've been subjected to my entire life. The ductless mini-splits are a totally different animal. I am completely sold on them and totally impressed by their performance as well. The only problem is the turn-off from having to deal with the installers who quote ridiculous prices for them - 100% markups or more on a $1500 heat pump to run an eight foot refrigerant line up an outside wall and directly into a head unit. If that install cost problem gets solved, these things will proliferate like crazy.



So you just need two tools and it can easily be done by a homeowner? This makes the deal much, much cheaper. I'm pretty handy from years of working on cars, but this is my first experience as a homeowner and I'm finding that most stuff isn't that hard. I've just never had to deal with house problems before.


----------



## Brian26

Ashful said:


> Way late to this thread, and I didn’t read the responses, but I do have three minisplits.  They are fantastic in what I believe are your typical winter temperatures, above maybe 20 or 25F.  However, when temps dip into the teens, they really struggle to keep up, and they burn a ton of electrons.  If you have electric resistive, the minisplits might be a great addition, given your climate.  Run the minisplits down to maybe 25F, then switch over to the resistive.



Not sure how old your units are but newer mini splits can operate in some severe cold with impressive heat output. My cheap Chinese unit I just installed claims full heat output at 5 degrees and its cut off is -13. It is AHRI (American Heat and Refrigeration Institute) certified to that temperature meaning it was actually tested in a lab setting to back that up. 

The newer high end Mitsubishi and Fujitsu splits are producing full heat to even lower temps and the technology is improving every year.


----------



## peakbagger

SpaceBus said:


> So you just need two tools and it can easily be done by a homeowner? This makes the deal much, much cheaper. I'm pretty handy from years of working on cars, but this is my first experience as a homeowner and I'm finding that most stuff isn't that hard. I've just never had to deal with house problems before.



There are plenty of videos on YouTube on how to install a mini split. Some folks take short cuts and hope. The compromise that I and several other folks have done is do the majority of the install and then pay a tech with the tools and skills to do the final hookup. Note if you elect to do that, there is no warranty on the unit as the selling dealer has the responsibility to do any warranty. Its a racket and that is why the dealers get away with charging high install rates.


----------



## Brian26

peakbagger said:


> There are plenty of videos on YouTube on how to install a mini split. Some folks take short cuts and hope. The compromise that I and several other folks have done is do the majority of the install and then pay a tech with the tools and skills to do the final hookup. Note if you elect to do that, there is no warranty on the unit as the selling dealer has the responsibility to do any warranty. Its a racket and that is why the dealers get away with charging high install rates.



They are really not that hard to install. Some of the higher end units like Mitsubishi want you to pressure test and flush with nitrogen but millions of these are installed all over the world with just pulling a vacuum verifying it doesn't leak under vacuum and then opening the refrigerant lines on the condenser.

The install itself is pretty easy. Mount the bracket for the wall unit, cut a hole for lines, mounting the condenser on the ground and run the lines.

The vacuum part is pretty easy. You use a valve core removal tool to remove the service schrader valve. This allows for a good deep vaccum as the schrader valve restricts flow but is not necessary.  The valve core removal tool has a port for a micron gauge with a valve to isolate the pump. You basically pull a vacuum measured in microns to under 500. Close the valve on the tool and verify it holds under 500 and then just install the schrader back in and open the valve on the condenser to let refrigerant in.

I got my unit down to 108 microns and it held at 282 for over an hour. The zero on the gauge under the 282 is the hour leak rate which was zero.

Here are a few pictures.


----------



## SpaceBus

peakbagger said:


> There are plenty of videos on YouTube on how to install a mini split. Some folks take short cuts and hope. The compromise that I and several other folks have done is do the majority of the install and then pay a tech with the tools and skills to do the final hookup. Note if you elect to do that, there is no warranty on the unit as the selling dealer has the responsibility to do any warranty. Its a racket and that is why the dealers get away with charging high install rates.



No warranty on the unit is fine since I can pay to replace it several times for the cost of an install it seems.


----------



## Brian26

SpaceBus said:


> No warranty on the unit is fine since I can pay to replace it several times for the cost of an install it seems.



My thoughts exactly. I was quoted over 5k for a professional install. I paid $800 for my unit and can install 5 more and still be ahead...


----------



## maple1

Highbeam said:


> You’re right about our climate temperatures and even better is that when it’s cold it is usually also very low winds. We occasionally dip into the single digits but not often and not for extended time.
> 
> If I were to install a heat pump I would keep the resistance heaters.




If I was in front of my computer I'd type more.

We got 2 Daikins installed in November.  

Just do it.


----------



## Ashful

Brian26 said:


> Not sure how old your units are but newer mini splits can operate in some severe cold with impressive heat output. My cheap Chinese unit I just installed claims full heat output at 5 degrees and its cut off is -13. It is AHRI (American Heat and Refrigeration Institute) certified to that temperature meaning it was actually tested in a lab setting to back that up.
> 
> The newer high end Mitsubishi and Fujitsu splits are producing full heat to even lower temps and the technology is improving every year.



Hi Brian,

I am currently running one installed in 2013, and another with dual indoor units installed 2015, all new Mitsubishi units.  The 2013 one does better than the dual head 2015 unit, in the cold, but it’s also seeing about 1/10th the load.

Maybe my troubles are more about incorrect sizing of the unit, which I had originally suspected, but I’ve had two tech’s out here to evaluate and both seem to think it’s sized right.


----------



## Brian26

Its 10 degrees here outside right now and this thing is pumping out some serious heat. I measured 100 degrees coming out of the vent. Wow!


----------



## begreen

When installing did you need to cut and flare the linesets or did you get a fixed length and coil up the extra. Also, does the condensate drain just get bundled with the lineset coming out of the head unit and drain on the ground?

Sounds like it's doing well so far. Tonight will be the real test.


----------



## Brian26

begreen said:


> When installing did you need to cut and flare the linesets or did you get a fixed length and coil up the extra. Also, does the condensate drain just get bundled with the lineset coming out of the head unit and drain on the ground?
> 
> Sounds like it's doing well so far. Tonight will be the real test.



I did have to cut the lineset and I read to not trust the factory flares so I made new flares. This yellow jacket flare tool makes perfect flares and is designed for 410a mini splits. Worth the investment if you are going the diy route. 

https://yellowjacket.com/product/deluxe-45-flaring-tool/

Its -1 here now outside and I did run the unit to test the cold weather output and its still cranking out great heat. According to a chart in the install manual its running at about 70% capacity. At -13 it cuts out but is still running at 5 0%. What will be interesting to see is above 44 degrees it will actually put out 130%+ of its rated output.


----------



## Brian26

Its -1 outside right now which is extremely rare for here and I hooked up my FLIR camera. Still putting out great heat with a 96.7 degree duct temp.


----------



## maple1

I meant to do this ever since we got ours in a couple months ago, but didn't until this thread made me.

I just dug my IR gun out, and replaced the dead battery. Shot the iron pipes on my boiler, that had thermometers in them and it was bang on (at 75 & 95, boiler not burning). Just shot inside the air outlet on the heat pump, and it said 130. Did it a few times, same thing every time. I'm a bit suspicious of that, I wasn't expecting it to be that high. But it definitely is very warm. It is -7c outside & dropping. Was +12c when I went to bed. I think it is using 700 watts +/- at the moment, guesstimating from what the energy monitor is saying. I will likely shut it down again later today & go back to the woodpile. With the cold spell of the last couple weeks, yesterday was the first time I've had them running in about that long.

My installer had a very snazzy flaring tool, it had a torque wrench built into it so you couldn't over flare the fittings. I should have asked how much $$ it cost - sure looked big bucks, all chrome & shiney & all. In a set with different sized jaws & stuff.

I hope to have a decent idea late spring on how much electricity $$ saved me on how much less wood burned. But yeah, Highbeam, just do it. As long as you get a good one.

(Our upstairs unit is a floor mount, actually fastened to the wall right above the baseboard. I am really impressed with that one. It can send heat out in two directions, from the bottom & top. So also heats the floor a bit right where wifeys feet land when she gets up in the morning. Check it.  )


----------



## Brian26

Its 1 degree right now and I went outside and shot the condenser with my FLIR and also used a temperature probe on my multi meter to verify the reading. I got -20 on the condenser fan temp output.

The unit is on turbo mode calling for full heat and is putting out 90 degrees at the ducts. I checked it on auto with a lower fan speed and it was around 120. Will have to experiment if its better to keep it on a higher fan speed.

I think the cold weather performance of it is verified. I do have a fire going but If I installed another one upstairs I think I could say goodbye to the oil furnace.

My solar panels are currently producing enough power to run the mini split load as well.


----------



## Highbeam

Brian26 said:


> Its 1 degree right now and I went outside and shot the condenser with my FLIR and also used a temperature probe on my multi meter to verify the reading. I got -20 on the condenser fan temp output.
> 
> The unit is on turbo mode calling for full heat and is putting out 90 degrees at the ducts. I checked it on auto with a lower fan speed and it was around 120. Will have to experiment if its better to keep it on a higher fan speed.
> 
> I think the cold weather performance of it is verified. I do have a fire going but If I installed another one upstairs I think I could say goodbye to the oil furnace.
> 
> My solar panels are currently producing enough power to run the mini split load as well.
> View attachment 238783
> View attachment 238784



When this this is in “balls out” mode to make heat how is the sound level? Like a refrigerator, woodstove blower, or hair dryer?


----------



## georgepds

Tegbert said:


> I’ve been looking at adding some to my house too. I’m Leary of what some people say that they can heat/cool a large area with one head unit. I have even been told that by most installers that we wouldn’t notice much heating or cooling down to our bedrooms.
> ...




I heat a 25x30 ft area (one Fujitsu 12k RLS heat pump per floor, one head per floor). I arranged the pumps so that they blow in through the BR doors.If you want a cooler BR, close the doors. If you want a warm but not hot BR, leave the door open a tad

Don't know if you count it as a big area, but each pump  keeps each floor toasty, ( Well, not quite toasty in this 3F weather, more like 68F inside). In the summer they will cool everything . The big red arrows show the rough airflow. You can feel the breeze in the BR when you stand in the doorway,. FWIIW, the heat pump heads have louvers so that you can direct the air

I do run the four fans in the winter to stir things up. I measured considerable stratification in the second floor cathedral room ( ~ 1F/ft) until I turned on the fans. On the first floor the fans are used more to stir up the hot air from the wood stove. Because the thermometer is in the head, you want to make sure the pump is at or near the same temperature as the ground. I mount mine ~ 8 feet high


----------



## georgepds

Highbeam said:


> ....
> These things are several thousand dollars. 2-3 for the unit and then who knows how much for install. I hate hiring people but this skillset is very unique.



Re hiring...

I could  only find an HVAC firm to install the units if I bought it from them. it requires two trades: electric and HVAC


----------



## georgepds

Highbeam said:


> When this this is in “balls out” mode to make heat how is the sound level? Like a refrigerator, woodstove blower, or hair dryer?



There is no sound inside or out. The only way I can tell if it is running is if I stand in the breeze

I really would not believe me, since my hearing sucks, but my wife, who can hear a 120 mm computer fan in a 1/2" pine cabinet,says the computer fan is louder

If all she could hear was a fan, I'd be golden, But she can hear a low level fart at 50 m, which does me in every time


----------



## begreen

Brian26 said:


> Its -1 here now outside and I did run the unit to test the cold weather output and its still cranking out great heat. According to a chart in the install manual its running at about 70% capacity. At -13 it cuts out but is still running at 5 0%. What will be interesting to see is above 44 degrees it will actually put out 130%+ of its rated output.


Fantastic for such an inexpensive little unit. Our normal winter temps are in the low 40s so this would work very well out here.


----------



## maple1

georgepds said:


> There is no sound inside or out. The only way I can tell if it is running is if I stand in the breeze
> 
> I really would not believe me, since my hearing sucks, but my wife, who can hear a 120 mm computer fan in a 1/2" pine cabinet,says the computer fan is louder
> 
> If all she could hear was a fan, I'd be golden, But she can hear a low level fart at 50 m, which does me in every time



There is no doubt it's running, when putting heat out. Full speed & max heat is fairly loud if you are near it. But just maintaining, it varies between lower amounts.

Best for someone to find one & hang out next to it for a while if they are definitely concerned about it.

(Our floor mount is a lot quieter than the wall mount though, it seems).


----------



## peakbagger

I do want to point out that even though the units may be putting toasty air down to zero that the efficiency is getting close to electric baseboard. IMHO the air movement required to move the air around increases the comfort temperature due to the convective cooling from the breeze. I think folks are far better running radiant baseboard or other alternatives when the temps get down to 10 F or lower but every house will be different. On both my Mitsubishi units, there are three setting for fan speed. Low is quite quiet, far quieter than a window AC unit. Medium is noticeable but not objectionable, high is definitely noticeable and I have to turn up my TV volume to compensate.  I find that when I run the unit on high I am mostly trying to get the heat to move around the house farther from the unit. In real cold weather the farther rooms get decidedly colder.

The other thing to keep in mind is these devices do not magically change the laws of physics. If you selected mini splits to meet the design heat load like a furnace there would be several of them lined up next to each other. These are really just fan forced space heaters, great for supplement heat but not so good for a primary heating system.

I do like mine and recommend them to a lot of folks but get worried that some folks listed to the hype and think that they are a viable substitute for  a primary heating system in cold climates, they aren't but they sure make a great supplement especially for folks who are now starting to see a need for AC where they used to not need it.


----------



## Tegbert

georgepds said:


> I heat a 25x30 ft area (one Fujitsu 12k RLS heat pump per floor, one head per floor). I arranged the pumps so that they blow in through the BR doors.If you want a cooler BR, close the doors. If you want a warm but not hot BR, leave the door open a tad
> 
> Don't know if you count it as a big area, but each pump  keeps each floor toasty, ( Well, not quite toasty in this 3F weather, more like 68F inside). In the summer they will cool everything . The big red arrows show the rough airflow. You can feel the breeze in the BR when you stand in the doorway,. FWIIW, the heat pump heads have louvers so that you can direct the air
> 
> I do run the four fans in the winter to stir things up. I measured considerable stratification in the second floor cathedral room ( ~ 1F/ft) until I turned on the fans. On the first floor the fans are used more to stir up the hot air from the wood stove. Because the thermometer is in the head, you want to make sure the pump is at or near the same temperature as the ground. I mount mine ~ 8 feet high
> View attachment 238818



That’s a decent area but In my house it is about 25’ wide by 64’ long. I see how yours does make it work though I just don’t see one head unit in my home making the far reaches comfortable without overheating the room it’s in. I mean my insert can make the far reaches comfortable and bearable heat in that room so maybe it’s possible. Just would be more efficient in my eyes to split it up more. 


Lopi Rockport
Blaze King Ashford 25


----------



## Tegbert

peakbagger said:


> I do want to point out that even though the units may be putting toasty air down to zero that the efficiency is getting close to electric baseboard. IMHO the air movement required to move the air around increases the comfort temperature due to the convective cooling from the breeze. I think folks are far better running radiant baseboard or other alternatives when the temps get down to 10 F or lower but every house will be different. On both my Mitsubishi units, there are three setting for fan speed. Low is quite quiet, far quieter than a window AC unit. Medium is noticeable but not objectionable, high is definitely noticeable and I have to turn up my TV volume to compensate.  I find that when I run the unit on high I am mostly trying to get the heat to move around the house farther from the unit. In real cold weather the farther rooms get decidedly colder.
> 
> The other thing to keep in mind is these devices do not magically change the laws of physics. If you selected mini splits to meet the design heat load like a furnace there would be several of them lined up next to each other. These are really just fan forced space heaters, great for supplement heat but not so good for a primary heating system.
> 
> I do like mine ands recommend them to a lot of folks but get worried that some folks listed to the hype and think that they are a viable substitute for  a primary heating system in cold climates, they aren't but they sure make a great supplement especially for folks who are now starting to see a need for AC where they used to not need it.



So if you recommend not getting rid of the baseboard heat then what would you do in place of them? Meaning like my baseboards take up a lot of wall space that I would like back for furniture or other things that I now have to keep clear. If they end up being equivalent to baseboard heat in lower temps do they just do a poorer job of heating a space? My goal is to rid the house of baseboard heat and in the PNW I think most of our weather would be ok with using just them. 


Lopi Rockport
Blaze King Ashford 25


----------



## maple1

I don't find baseboards take much space away. If you say back a couch up against a wall, the top will hit the wall way before the bottom will hit the baseboard - then just pull it back out an inch or so. If it's something else straighter like a shelf, not a big thing to ease it up against the baseboard. I have some narrow strips of boards in the odd place laying on the floor under the baseboard to stop something from being shoved in too hard against them.

Also, a heat pump will send heat out across a space a lot further than a stove will. They can really move air if you bump the speed up.


----------



## maple1

peakbagger said:


> I do want to point out that even though the units may be putting toasty air down to zero that the efficiency is getting close to electric baseboard. IMHO the air movement required to move the air around increases the comfort temperature due to the convective cooling from the breeze. I think folks are far better running radiant baseboard or other alternatives when the temps get down to 10 F or lower but every house will be different. On both my Mitsubishi units, there are three setting for fan speed. Low is quite quiet, far quieter than a window AC unit. Medium is noticeable but not objectionable, high is definitely noticeable and I have to turn up my TV volume to compensate.  I find that when I run the unit on high I am mostly trying to get the heat to move around the house farther from the unit. In real cold weather the farther rooms get decidedly colder.
> 
> The other thing to keep in mind is these devices do not magically change the laws of physics. If you selected mini splits to meet the design heat load like a furnace there would be several of them lined up next to each other. These are really just fan forced space heaters, great for supplement heat but not so good for a primary heating system.
> 
> I do like mine ands recommend them to a lot of folks but get worried that some folks listed to the hype and think that they are a viable substitute for  a primary heating system in cold climates, they aren't but they sure make a great supplement especially for folks who are now starting to see a need for AC where they used to not need it.



Depends on the definition of 'cold climate'. Based on our experience so far, I think I could do all our heating (2700 broken up square feet) with 3 12k heads. Down to at least -20c intermittently. For less fuel cost than anything except wood. If I was going to try that though, I would certainly still want something that burns wood. For power outages & maybe some odd supplementing when I felt like it.

Now, if I was in some central places in this continent where -20c is considered a semi-mild spell - that would be entirely different.


----------



## Highbeam

If your stove can heat the whole house from one room then why couldn’t a single head heat pump? I fail to see the difference. Btu are btu right?

I’m sure a lot of things vary from house to house but many folks heat their homes with a single woodstove. I have heard the same odd logic about woodstoves too, just space heaters. Well yeah, the space is your home!

Putt temperatures here in the pnw on average are above freezing but I would not size a heat pump based on that. Instead, use the coldest day. Say 5 degrees that you need to be ready for.


----------



## Ashful

peakbagger said:


> I do want to point out that even though the units may be putting toasty air down to zero that the efficiency is getting close to electric baseboard. IMHO the air movement required to move the air around increases the comfort temperature due to the convective cooling from the breeze. I think folks are far better running radiant baseboard or other alternatives when the temps get down to 10 F or lower but every house will be different. On both my Mitsubishi units, there are three setting for fan speed. Low is quite quiet, far quieter than a window AC unit. Medium is noticeable but not objectionable, high is definitely noticeable and I have to turn up my TV volume to compensate.  I find that when I run the unit on high I am mostly trying to get the heat to move around the house farther from the unit. In real cold weather the farther rooms get decidedly colder.
> 
> The other thing to keep in mind is these devices do not magically change the laws of physics. If you selected mini splits to meet the design heat load like a furnace there would be several of them lined up next to each other. These are really just fan forced space heaters, great for supplement heat but not so good for a primary heating system.
> 
> I do like mine and recommend them to a lot of folks but get worried that some folks listed to the hype and think that they are a viable substitute for  a primary heating system in cold climates, they aren't but they sure make a great supplement especially for folks who are now starting to see a need for AC where they used to not need it.



My experience, exactly.  I have owned five Mitsubishi mini splits, in three different buildings.  I also have a few in my lab at work.


----------



## Ashful

maple1 said:


> I don't find baseboards take much space away. If you say back a couch up against a wall, the top will hit the wall way before the bottom will hit the baseboard - then just pull it back out an inch or so.



I think he is talking about electric baseboards, which unlike hydronic, can melt your couch or set fire to your book case.


----------



## SpaceBus

Ashful said:


> I think he is talking about electric baseboards, which unlike hydronic, can melt your couch or set fire to your book case.



I have not found that experience with our 70's Merkel 750 watt electric baseboard heaters. I just keep stuff five inches or so away and that's seems fine. We don't block them for fear of a fire, but so we don't block the heat. I agree that they do force some furniture arrangements when in use. Ours also don't run that much and take over when the stove dies down if we are away or asleep and don't feel like getting up to load the stove. I think we will be getting up tonight to load the stove though. This is the coldest night we've had so far, but we also just got here in November.


----------



## Ashful

SpaceBus said:


> I have not found that experience with our 70's Merkel 750 watt electric baseboard heaters. I just keep stuff five inches or so away and that's seems fine. We don't block them for fear of a fire, but so we don't block the heat. I agree that they do force some furniture arrangements when in use. Ours also don't run that much and take over when the stove dies down if we are away or asleep and don't feel like getting up to load the stove. I think we will be getting up tonight to load the stove though. This is the coldest night we've had so far, but we also just got here in November.


I guess it might vary by brand and wattage.  My last house had electric baseboard in all five bedrooms, and the upstairs bathroom.  More than one of them had melted material on their guards, from where prior owners let synthetic drapes or furniture get too close.


----------



## Tegbert

Highbeam said:


> If your stove can heat the whole house from one room then why couldn’t a single head heat pump? I fail to see the difference. Btu are btu right?
> 
> I’m sure a lot of things vary from house to house but many folks heat their homes with a single woodstove. I have heard the same odd logic about woodstoves too, just space heaters. Well yeah, the space is your home!
> 
> Putt temperatures here in the pnw on average are above freezing but I would not size a heat pump based on that. Instead, use the coldest day. Say 5 degrees that you need to be ready for.



I guess I should have specified about that more. Yes my insert can keep the house heated. So can my stove. I’ve never tried that with let’s say just my living room baseboards but I am trying it now. My concern is I want the AC. We use a portable ac in the living room a 12,000 btu one and it can’t keep up in the living room. Yes it’s more comfortable than what it would be without it but I want it cooler in there. It definitely doesn’t do much for the bedroom last down the hall either that I have to run a 9000 btu one in the master. That one does seem to keep the master good since I like it cold to sleep but the other rooms across the hall are still too warm. So when an installer says a 12000 btu head will cool the living room and down the hall I have doubts about that. Yeah the mini split one is probably more efficient but how much better does it do than a portable version?


Lopi Rockport
Blaze King Ashford 25


----------



## maple1

Tegbert said:


> I guess I should have specified about that more. Yes my insert can keep the house heated. So can my stove. I’ve never tried that with let’s say just my living room baseboards but I am trying it now. My concern is I want the AC. We use a portable ac in the living room a 12,000 btu one and it can’t keep up in the living room. Yes it’s more comfortable than what it would be without it but I want it cooler in there. It definitely doesn’t do much for the bedroom last down the hall either that I have to run a 9000 btu one in the master. That one does seem to keep the master good since I like it cold to sleep but the other rooms across the hall are still too warm. So when an installer says a 12000 btu head will cool the living room and down the hall I have doubts about that. Yeah the mini split one is probably more efficient but how much better does it do than a portable version?
> 
> 
> Lopi Rockport
> Blaze King Ashford 25



The split will send the heat (or cold) out further than a stove or radiators. I was surprised how far ours sends it. The fans really distribute the air out & around - much more so than a window shaker if talking a/c. More fan ooomph.


----------



## georgepds

Tegbert said:


> I guess I should have specified about that more. Yes my insert can keep the house heated. So can my stove. I’ve never tried that with let’s say just my living room baseboards but I am trying it now. My concern is I want the AC. We use a portable ac in the living room a 12,000 btu one and it can’t keep up in the living room. Yes it’s more comfortable than what it would be without it but I want it cooler in there. It definitely doesn’t do much for the bedroom last down the hall either that I have to run a 9000 btu one in the master. That one does seem to keep the master good since I like it cold to sleep but the other rooms across the hall are still too warm. So when an installer says a 12000 btu head will cool the living room and down the hall I have doubts about that. Yeah the mini split one is probably more efficient but how much better does it do than a portable version?
> 
> 
> Lopi Rockport
> Blaze King Ashford 25



By all means, get a manual j calculation to size the equipment


That said, the rule of thumb is 12kbtu/hr for each 600 ft^2. By that rule your AC should be 2x bigger


----------



## SpaceBus

georgepds said:


> By all means, get a manual j calculation to size the equipment
> 
> 
> That said, the rule of thumb is 12kbtu/hr for each 600 ft^2. By that rule your AC should be 2x bigger



Thank you for posting this, I had no idea. When we selected our wood stove I used an online calculator.


----------



## Brian26

Pretty neat how these inverters run. It seems to start out at about 20% output and slowly ramps up to full speed over the course of an hour then quickly goes down.  This was on the auto heat setting. I can set it on turbo if I need to and it will run at max capacity.

 Here was 2 hours of run time graphed. Outside temp was 25 and it was set to 70.


----------



## twd000

have these technology advances spilled over to the central heat pump units?  Are they now able to run efficiently down to single digit temperatures?  

I already have central A/C and ductwork.  Could I replace my propane furnace with a high efficiency heat pump and come out ahead?


----------



## maple1

twd000 said:


> have these technology advances spilled over to the central heat pump units?  Are they now able to run efficiently down to single digit temperatures?
> 
> I already have central A/C and ductwork.  Could I replace my propane furnace with a high efficiency heat pump and come out ahead?



I would likely tend to replacing the A/C unit and keeping the propane unit. Yes, there have been advances. You can get a mini-split system that has the indoors part in your ductwork.


----------



## twd000

Replace the outdoor A/C condenser with a heat pump? And leave the indoor air handler and propane furnace for backup? It would be nice to wire the thermostat and control to switch from the heat pump to propane when the outdoor temp gets below ? Degrees

Do you have a link to the indoor units that work with the ductwork?


----------



## Tegbert

twd000 said:


> Replace the outdoor A/C condenser with a heat pump? And leave the indoor air handler and propane furnace for backup? It would be nice to wire the thermostat and control to switch from the heat pump to propane when the outdoor temp gets below ? Degrees
> 
> Do you have a link to the indoor units that work with the ductwork?



My parents have a heat pump hooked to a propane furnace. The heat pump works for them down to 15° or so then switches to propane. It should be relatively easy to switch out as long as the furnace is still in good condition. 


Lopi Rockport
Blaze King Ashford 25


----------



## twd000

Yes the furnace is in good shape. Current propane price is about $2.50/gallon. Furnace is 90% AFUE. 

How do I estimate cost savings for a heat pump? All-inclusive electric rate is about $0.20/kWh


----------



## woodgeek

HP will usually have higher tonnage (and need bigger ducts and airhandler) than AC for the same space.  FYI.


----------



## twd000

unless I'm missing something here, I don't see the savings for my fuel choices

ignoring distribution and duct losses (which would be the same for central heat pump and furnace)

propane: $2.15/gal / 92,000 BTU * 1,000,000 MBTU = $23.37/MBTU 
heat pump w/ avg 2 COP: $0.20/kWh / 3,412 BTU / 2 COP * 1,000,000 MBTU = $29.31, or 25% MORE than propane.
If I optimistically assume 3 COP, it's only $19.54, or 15% savings over propane.  Seems like it would take a long time to payback new heat pump equipment at a COP of 3, and at a more realistic COP of 2, it actually would cost me more.


----------



## maple1

There is also combustion (in)efficiency with LP that should be factored in.

I don't know what LP prices are around here but I think around 0.90/litre.

Electricity used is 0.15/kwh.

My heat pumps spec at 3.8 & 4.0 COP.

Assuming a COP of 3 and ignoring LP inefficiency, I get 36.22 for LP & 14.65 for splits.

Wide variations place to place of course. And COP would vary with outside temp - we're fairly moderate but also very varying. Was -16c here this morning.

Our fuel oil costs I think would be similar to LP.


----------



## twd000

maple1 said:


> There is also combustion (in)efficiency with LP that should be factored in.
> 
> I don't know what LP prices are around here but I think around 0.90/litre.
> 
> Electricity used is 0.15/kwh.
> 
> My heat pumps spec at 3.8 & 4.0 COP.
> 
> Assuming a COP of 3 and ignoring LP inefficiency, I get 36.22 for LP & 14.65 for splits.
> 
> Wide variations place to place of course. And COP would vary with outside temp - we're fairly moderate but also very varying. Was -16c here this morning.
> 
> Our fuel oil costs I think would be similar to LP.




good point on the furnace efficiency - the label on mine claims 92.5 AFUE, so my propane cost is really $25.26/MBTU
Your propane is even more expensive than ours

Having a hard time finding real world COP -  are you really averaging COP 3 across an entire winter?  I have seen #'s from 2-4 COP which makes a huge difference


----------



## maple1

twd000 said:


> good point on the furnace efficiency - the label on mine claims 92.5 AFUE, so my propane cost is really $25.26/MBTU
> Your propane is even more expensive than ours
> 
> Having a hard time finding real world COP -  are you really averaging COP 3 across an entire winter?  I have seen #'s from 2-4 COP which makes a huge difference



I just kind of pulled 3 out of the air. Rated at 4. But I really have no idea what it would be averaged over a winter.


----------



## Brian26

Got to test the unit out in some milder weather. Was in the 40s yesterday and is currently 50 out. Heat output really goes way up in these temps. What I didn't realize is it is actually rated at putting out around 17k btus when its above 44 degrees outside. Pretty impressive for a 110v 12k unit.


----------



## Brian26

Been doing extensive testing and monitoring since my install and these things are incredible at pumping out heat in very cold weather. I have sensors monitoring return and supply air and my efergy monitoring its power consumption.

This unit can prettty much always maintain a 30-40 degree temp rise between the return and supply air (delta t). Here is a chart from overnight when I fired it up this morning. Intake temp was 64 and it was putting out 105 degree duct air within minutes. Outside temp was 9 degrees.


----------



## SpaceBus

Did it feel like 64? Between loads while we sleep (or if I don't wake up to load the stove) the house gets down to 62-64 depending how long it has been. The electric baseboard heaters take over if it gets down to 62. While I'm awake or if I wake up to load the stove it never goes below 68 and usually it's above 72 inside. Our house is small, so I can raise the first floor temp close to 3 degrees an hour. Even faster if the sun is out.

I have the thermostat set so low because the baseboard heat is expensive and I can usually reload before the house gets cold. It would be nice to have cheap heat that feels warm. My wife like really has a thing about heat pump heat, she just stays cold. Sometimes she doesn't even warm by the stove!


----------



## Brian26

SpaceBus said:


> Did it feel like 64? Between loads while we sleep (or if I don't wake up to load the stove) the house gets down to 62-64 depending how long it has been. The electric baseboard heaters take over if it gets down to 62. While I'm awake or if I wake up to load the stove it never goes below 68 and usually it's above 72 inside. Our house is small, so I can raise the first floor temp close to 3 degrees an hour. Even faster if the sun is out.
> 
> I have the thermostat set so low because the baseboard heat is expensive and I can usually reload before the house gets cold. It would be nice to have cheap heat that feels warm. My wife like really has a thing about heat pump heat, she just stays cold. Sometimes she doesn't even warm by the stove!



I am still fine tuning the ideal setpoints. I have been letting the oil burner carry most of the load as its been pretty cold here. I am on the CT shoreline so these single digit temps are rare. When its in the 30s and 40s the oil burner is off. I have saved a ton on oil since I installed it. Looking forward to seeing the data when its in the high 50s next week.


----------



## semipro

SpaceBus said:


> My wife like really has a thing about heat pump heat, she just stays cold.


In many cases, this is due to evaporative cooling on skin from too high a fan speed in heating mode.  A variable speed ECM motor in the air handler can be retrofitted to address this issue.   You can also just rewire the air handler fan to run on its lowest speed.


----------



## SpaceBus

Brian26 said:


> I am still fine tuning the ideal setpoints. I have been letting the oil burner carry most of the load as its been pretty cold here. I am on the CT shoreline so these single digit temps are rare. When its in the 30s and 40s the oil burner is off. I have saved a ton on oil since I installed it. Looking forward to seeing the data when its in the high 50s next week.



We are on the coast, but the bays and harbors shield is from the worst of the weather. The wind will still take some heat from the house. Still, the stove will be doing most of the heating for our house, the mini splits would be back up, with the electric baseboards being back up for the mini splits.


----------



## SpaceBus

semipro said:


> In many cases, this is due to evaporative cooling on skin from too high a fan speed in heating mode.  A variable speed ECM motor in the air handler can be retrofitted to address this issue.   You can also just rewire the air handler fan to run on its lowest speed.



Well, we don't have an air handler at all on our new (built in 77) house. That at first made her very nervous, but she has warmed up to the electric baseboard heaters. I wish electrical service weren't so expensive here, but we knew there would be sacrifices to living in such a remote area. On a sunny day like today I have to use very little firewood, if any at all while the sun is up.


----------



## DBoon

SpaceBus said:


> It would be nice to have cheap heat that feels warm. My wife like really has a thing about heat pump heat, she just stays cold.


I can tell you that these mini-splits deliver warm heat. I too was once skeptical having lived with crappy ducted units that just pushed out cool air until the electric resistance strips kicked on. The mini-splits are way different than that.


----------



## peakbagger

I differ a bit on my perception of heat from my minisplit compared to baseboards. My boiler and storage is in the basement and it keeps the floor warm. I can set my thermostat several degrees lower when the basement is warm. I tend to take days off from burning in the winter and use the minisplit. Its quite noticeable that I need to run the minisplit at a higher temp to match the comfort level that I get away with burning wood. 

When I worked in offices there was always a battle over thermostats with women usually complaining they were too cold. We sometime would buy low wattage floor mat heaters for the ladies. It cut way down on complaints.


----------



## SpaceBus

peakbagger said:


> I differ a bit on my perception of heat from my minisplit compared to baseboards. My boiler and storage is in the basement and it keeps the floor warm. I can set my thermostat several degrees lower when the basement is warm. I tend to take days off from burning in the winter and use the minisplit. Its quite noticeable that I need to run the minisplit at a higher temp to match the comfort level that I get away with burning wood.
> 
> When I worked in offices there was always a battle over thermostats with women usually complaining they were too cold. We sometime would buy low wattage floor mat heaters for the ladies. It cut way down on complaints.



This is exactly what I needed to hear. While we do not have hot water baseboard heaters, ours are electric, my wife still prefers them over forced air now that she trusts them to not burn the house down. This makes me less in a hurry to change them, she is leery of a DIY install and getting a pro to do it is crazy expensive.


----------



## maple1

One of our units is a 'floor mount'. Still attached to the wall but sits on the floor. It can send heat out both low along the floor and from the top, into the middle of the room. I think it improves the 'warm but feels cool' thing.


----------



## SpaceBus

maple1 said:


> One of our units is a 'floor mount'. Still attached to the wall but sits on the floor. It can send heat out both low along the floor and from the top, into the middle of the room. I think it improves the 'warm but feels cool' thing.



The low mount makes a lot of sense. I don't think we could find a practical location for one in our house, unfortunately. Perhaps this is where the professional install makes more sense.


----------



## Ashful

Went out to my shop this morning, with dual Mitsubishi minisplits, and it was 45F in there.  Thermostats were set to 55, but system wasn’t running.  Bumped them both up to 70, and they started pumping heat straight away.  Weird, but par for the course, with these units.  

We’ve been hovering near zero for the last few days, but last night was a balmy 16F, and i think it even went up above freezing this afternoon.


----------



## Brian26

SpaceBus said:


> This is exactly what I needed to hear. While we do not have hot water baseboard heaters, ours are electric, my wife still prefers them over forced air now that she trusts them to not burn the house down. This makes me less in a hurry to change them, she is leery of a DIY install and getting a pro to do it is crazy expensive.



A mini split would save you a fortune over electric baseboard heaters. A good Mitsibushi or Fujitsu with a 12.5 HSPF would cost you almost 4 times less for a million BTU's.

Cost per million btu's.

Electric baseboard- $46.89
Mini Split-  $12.80.

www.pacificpud.org/heatcalc.xls


----------



## SciGuy

twd000 said:


> unless I'm missing something here, I don't see the savings for my fuel choices ignoring distribution and duct losses (which would be the same for central heat pump and furnace)
> *propane: $2.15/gal* / 92,000 BTU * 1,000,000 MBTU = $23.37/MBTUheat pump w/ avg 2 COP: $0.20/kWh / 3,412 BTU / 2 COP * 1,000,000 MBTU = $29.31, or 25% MORE than propane.
> If I optimistically assume 3 COP, it's only $19.54, or 15% savings over propane.  Seems like it would take a long time to payback new heat pump equipment at a COP of 3, and at a more realistic COP of 2, it actually would cost me more.



Are you certain about your cost of propane? It looks way out of wack compared to current pricing here in Upstate NY.
When I Google propane prices in New Hampshire I find the following much less attractive value.








Hugh


----------



## twd000

Wow I don't know anyone paying $3.17, unless they're heating their house with 20-lb BBQ tanks! I buy as part of a co-op and they set rates every spring based on usage. What are you paying in NY?


----------



## SciGuy

twd000 said:


> Wow I don't know anyone paying $3.17, unless they're heating their house with 20-lb BBQ tanks! I buy as part of a co-op and they set rates every spring based on usage. What are you paying in NY?



IIRC it cost $2.90/gallon for a fill up in the middle of last winter and prices are running as high as $3.75/gallon this year in the north country. So if you called for a fill up today it would only run $2.15 or was that the summer time price?


----------



## twd000

SciGuy said:


> IIRC it cost $2.90/gallon for a fill up in the middle of last winter and prices are running as high as $3.75/gallon this year in the north country. So if you called for a fill up today it would only run $2.15 or was that the summer time price?



yes this was the pre-buy price - the co-op always sets rates after the heating season ends so it's cheaper.  I'm not sure what I would pay in today's spot price with no contract, but I would guess closer to $2.50


----------



## Brian26

twd000 said:


> yes this was the pre-buy price - the co-op always sets rates after the heating season ends so it's cheaper.  I'm not sure what I would pay in today's spot price with no contract, but I would guess closer to $2.50



The EIA has propane prices at $3.28 a gallon as of 01/28 in New Hampshire. Thats the average of what most are paying. 

https://www.eia.gov/dnav/pet/PET_PRI_WFR_DCUS_SNH_W.htm

My heat pump with a hspf of 12 would still cost half to run using your  $2.15 propane price.

Using the above fuel cost calculator and thr EIA for .16 kwh price in NH.

Per millions btus.

Mini split.              13.33
2.15 propane        26.16
Eia 3.29 average. 40.03


----------



## twd000

Brian26 said:


> The EIA has propane prices at $3.28 a gallon as of 01/28 in New Hampshire. Thats the average of what most are paying.
> 
> https://www.eia.gov/dnav/pet/PET_PRI_WFR_DCUS_SNH_W.htm
> 
> My heat pump with a hspf of 12 would still cost half to run using your  $2.15 propane price.
> 
> Using the above fuel cost calculator and thr EIA for .16 kwh price in NH.
> 
> Per millions btus.
> 
> Mini split.              13.33
> 2.15 propane        26.16
> Eia 3.29 average. 40.03




I don't know what to tell ya.  I promise I'm not sleeping with my propane delivery guy!


----------



## Brian26

twd000 said:


> I don't know what to tell ya.  I promise I'm not sleeping with my propane delivery guy!
> 
> 
> 
> 
> 
> 
> 
> 
> 
> View attachment 240184



Looks like you pay a good price. I was just pointing out that a good mini split would cost you half even at $2.15 propane. The majority of people that pay the retail price of $3.29 would save almost 3 times the amount. 

On a related note. I finally got to run my unit in some milder weather. Its in the 40's this morning and its pumping out 136 degree heat with a 71 return air temp. An impressive almost 70 degree temp rise across the evaporator!

Another added benefit of these mini splits is they don't dry out the air according to my sensor monitoring on the return and supply.


----------



## twd000

yeah, days like this (mid-50's) are where it seems silly to burn wood, even with the BK Princess chugging away at a low tstat setting.  I would love to let a heat pump carry the load until it gets real cold again.

I'm not familiar with that HSPF metric, but the $13.33/MBTU you quoted equals COP=3.5 which I'm more familiar with.  That is pretty admirable, if it can average that high COP across the heating season.


----------



## CaptSpiff

I find propane prices to be very regional. We get choked here on Long Island:

https://www.nyserda.ny.gov/Researchers-and-Policymakers/Energy-Prices/Propane/Average-Propane-Prices


----------



## begreen

Likewise in our area. Propane prices are high here.


----------



## CaptSpiff

Brian26 said:


> Another added benefit of these mini splits is they don't dry out the air according to my sensor monitoring on the return and supply.
> View attachment 240185


I always thought the "dry indoor air in winter" was more the result of exchanging indoor air with outdoor air, as in "leaky house allows warm humid air to escape and be replaced with dry outside air which is heated and becomes even dryer".


----------



## woodgeek

twd000 said:


> I'm not familiar with that HSPF metric, but the $13.33/MBTU you quoted equals COP=3.5 which I'm more familiar with.  That is pretty admirable, if it can average that high COP across the heating season.



HSPF is just COP*3.412, its the BTU/Wh expected, while COP is Wh(heat)/Wh(electrical).  SEER is on the same basis.


----------



## twd000

woodgeek said:


> HSPF is just COP*3.412, its the BTU/Wh expected, while COP is Wh(heat)/Wh(electrical).  SEER is on the same basis.




thanks I didn't realize it was a simple linear relationship.  Will the same minisplit have different COP/HSPF based on climate heating degree days?


----------



## woodgeek

Yeah...its a seasonal average COP (or SCOP) for some reference climate...that I do not know.


----------



## peakbagger

There is report out of the web done by DOE or some other organization that looks at real time efficiency of minisplits over a range of outdoor temperatures, my googling didn't find it but it definitely showed more than a linear degradation of performance as the temps dropped.


----------



## maple1

The main issue with apparent performance loss - is that not only is there less heat to move in the outside air when it is colder out, but your house also needs more heat to maintain because heat loss is going up at the same time.


----------



## Brian26

maple1 said:


> The main issue with apparent performance loss - is that not only is there less heat to move in the outside air when it is colder out, but your house also needs more heat to maintain because heat loss is going up at the same time.



That has been my observations a few weeks in on running mine. I have mine dialed in pretty good on when to run it and when to fall back on my oil furnace. Im down on the CT shoreline were winter temps are pretty mild most of the time in winter. This week its been mild and it has been running all week pumping out great heat. Its definitely cut back huge on running the oil furnace when I am at work during the day. 

I did run it the other week when it was around zero here at night and it still puts out heat. I still had to run the oil furnace but my downstairs was way warmer than before the minisplit went in. It also appears to really cut down on the oil furnace runtime when ran together when its cold.


----------



## DBoon

Before I purchased an installed a Fujitsu 12kBTU RLS2 mini split (rated down to -17 deg F), I researched the COP at different temperatures. I recall that this model was still a COP 2 or so at -5 degree F and was rated to deliver 12kBTU at or close to that temperature. And in below zero weather, it still heated the house and there was warm air coming out of the unit. But at -5 degree F, the house lost a lot more heat, so overall effectiveness went down.


----------



## Ashful

Based on the reports here, of these things actually working in sub-zero, I’ve been playing with mine.  Unfortunately, or fortunately, our sub-zero temps ended the day I started experimenting, and it’s been too warm ever since for any real data.

I see three general possibilities as the source of the trouble with mine:

1.  First floor indoor unit may be undersized for the load.  I have two machined PVC overhead doors (10 footers) in that space, and I believe the person who calc’d the HVAC load assumed a much higher R-value on those doors.  Of course, the doors are too beautiful and expensive to even consider swapping out, it’d cost much less to just replace that indoor unit with something larger.

2.  Temp sensing was set to be in the indoor unit, rather than in the wall-mounted thermostat, and this may be tricking the system to think the space is much warmer than it really is.  It was set up this way because I have the thermostats for both floors located next to the entry door, meaning one is on a different floor than the zone it is controlling.  I will see the dreaded “wait” symbol frequently appearing on the LCD thermostats, which is an indicator that one of the head units may be calling for cooling while the other is calling for heating. 

3.  The system is set up or charged wrong, although I’ve already had this checked.  The real indicator here will be measuring inlet/outlet air temp during our next sub-zero event.

For now, I’ve switched the temp sensing to be in the wall-mounted thermostats, and temporarily (and inconveniently) relocated the second floor thermostat to the second floor.  This seems to have ended some of the crazy behavior, like finding it’s 45F in the shop when I go out there for the evening, even though both thermostats were set to hold 55F.


----------



## maple1

Ashful said:


> Based on the reports here, of these things actually working in sub-zero, I’ve been playing with mine.  Unfortunately, or fortunately, our sub-zero temps ended the day I started experimenting, and it’s been too warm ever since for any real data.
> 
> I see three general possibilities as the source of the trouble with mine:
> 
> 1.  First floor indoor unit may be undersized for the load.  I have two machined PVC overhead doors (10 footers) in that space, and I believe the person who calc’d the HVAC load assumed a much higher R-value on those doors.  Of course, the doors are too beautiful and expensive to even consider swapping out, it’d cost much less to just replace that indoor unit with something larger.
> 
> 2.  Temp sensing was set to be in the indoor unit, rather than in the wall-mounted thermostat, and this may be tricking the system to think the space is much warmer than it really is.  It was set up this way because I have the thermostats for both floors located next to the entry door, meaning one is on a different floor than the zone it is controlling.  I will see the dreaded “wait” symbol frequently appearing on the LCD thermostats, which is an indicator that one of the head units may be calling for cooling while the other is calling for heating.
> 
> 3.  The system is set up or charged wrong, although I’ve already had this checked.  The real indicator here will be measuring inlet/outlet air temp during our next sub-zero event.
> 
> For now, I’ve switched the temp sensing to be in the wall-mounted thermostats, and temporarily (and inconveniently) relocated the second floor thermostat to the second floor.  This seems to have ended some of the crazy behavior, like finding it’s 45F in the shop when I go out there for the evening, even though both thermostats were set to hold 55F.



You can't manually set them to heating mode?


----------



## Ashful

maple1 said:


> You can't manually set them to heating mode?



Yes, I can.  I probably should for the dead of winter, but I usually tend to leave all of my minisplit systems on auto-changeover, as they’re all in spaces that we might not see for a week or more at a time.  I also tend to treat every household system as if I could disappear tomorrow, leaving my wife and kids to figure it out.  In that case, my shop or music studio (our two minisplit systems) might sit un-visited several months or even a year at a time, and I’d rather not have everything in those spaces ruined for them when temps hit 0F or 100F.


----------



## Brian26

Ashful said:


> Based on the reports here, of these things actually working in sub-zero, I’ve been playing with mine.  Unfortunately, or fortunately, our sub-zero temps ended the day I started experimenting, and it’s been too warm ever since for any real data.
> 
> I see three general possibilities as the source of the trouble with mine:
> 
> 1.  First floor indoor unit may be undersized for the load.  I have two machined PVC overhead doors (10 footers) in that space, and I believe the person who calc’d the HVAC load assumed a much higher R-value on those doors.  Of course, the doors are too beautiful and expensive to even consider swapping out, it’d cost much less to just replace that indoor unit with something larger.
> 
> 2.  Temp sensing was set to be in the indoor unit, rather than in the wall-mounted thermostat, and this may be tricking the system to think the space is much warmer than it really is.  It was set up this way because I have the thermostats for both floors located next to the entry door, meaning one is on a different floor than the zone it is controlling.  I will see the dreaded “wait” symbol frequently appearing on the LCD thermostats, which is an indicator that one of the head units may be calling for cooling while the other is calling for heating.
> 
> 3.  The system is set up or charged wrong, although I’ve already had this checked.  The real indicator here will be measuring inlet/outlet air temp during our next sub-zero event.
> 
> For now, I’ve switched the temp sensing to be in the wall-mounted thermostats, and temporarily (and inconveniently) relocated the second floor thermostat to the second floor.  This seems to have ended some of the crazy behavior, like finding it’s 45F in the shop when I go out there for the evening, even though both thermostats were set to hold 55F.



I setup a return and supply temp sensor on mine that logs the data. Acurite that sells weather stations has cheap sensors.

The units have a temp sensor on the top intake that they use to regulate the temp. In cooling mode they work great  but in heating mode the intake is significantly air temp higher. I found about a 5-8 degree temp difference from 4 ft from the floor than on the intake. All that hot air rises. I can use thr follow me feature where my remote is the sensor.  Works way better but has to constantly be in communication with the wall unit. 

Another test is go measure the temps on the lines coming out of the condenser outside. There is a big one and a small one.  My bigger line is usually around 125-150 degrees depending on outdoor temps and load. That seems to be a rough number on most splits from research.

You can probably find the service manual online. It has a wealth of information on how they run.


----------



## twd000

another anecdote for what it's worth.  Just talked to a guy at church who had a Mitsu Hyperheat installed in his office a couple years ago.  I asked him how it did with our -5 cold snap last week, and he had only good things to say.  Toasty warm from his report.


----------



## Brian26

twd000 said:


> another anecdote for what it's worth.  Just talked to a guy at church who had a Mitsu Hyperheat installed in his office a couple years ago.  I asked him how it did with our -5 cold snap last week, and he had only good things to say.  Toasty warm from his report.



The Mitsbushi's can crank out some serious heat even in cold temps. Conventional heat pumps are getting crushed on efficiency.

This is no doubt going to be the future of heating and cooling...

100 percent heating capacity at 5 degrees is straight out nuts

Mine is running right now at 25 degrees and putting out 100 percent heat...


----------



## Highbeam

Brian26 said:


> The Mitsbushi's can crank out some serious heat even in cold temps. Conventional heat pumps are getting crushed on efficiency.
> 
> This is no doubt going to be the future of heating and cooling...
> 
> 100 percent heating capacity at 5 degrees is straight out nuts
> 
> Mine is running right now at 25 degrees and putting out 100 percent heat...
> 
> View attachment 240517



Just a matter of time before the conventional split system folks pull their heads out of their butts and improve their equipment to match.

Also heads in butts for those manufacturers who still haven’t decided to heat water with this technology.


----------



## begreen

Their head must be up there pretty far. I've been waiting 12 yrs now and what mostly has changed is that the companies that I saw overseas are now owning the market.


----------



## woodgeek

Highbeam said:


> Just a matter of time before the conventional split system folks pull their heads out of their butts and improve their equipment to match.
> 
> Also heads in butts for those manufacturers who still haven’t decided to heat water with this technology.



Actually, they HAVE.  All the major brands now have their top of the line compressors using inverter driven variable speed motors, with suitable controllers.  And they are getting higher SEER and HPSF bc of that. Its just that they are still selling the one and crappy two speed compressors a bit cheaper, and most people will go for the slightly lower install cost.  And IIRC Goodman was largely purchased by one of the East Asian HVAC companies several years ago, around the same time this tech rolled out.

Getting broad adoption (and resulting efficiency) would prob require DOE regulation.  In the meantime the makers will just see an opportunity to charge early adopters a premium.

As for water....most people delivering heat by hot water want temps high enough for passive radiators...and that is like 20-40°F hotter than air delivery temps, killing the COP.  And no cooling in practice.  So it might be popular in some nice, drier climates...but in the US with a lot of heat and humidity where most of the people live, its gonna be air delivery for a long time.

Unless you meant heating DHW....in which case the tech also already exists and is available at HomeDespot with COPs of 3+.  My 6 yo HPWH unit is going strong, but only has a COP of 2 or so.

And those are being forced in (slowly) with Obama-era DOE regs.


----------



## Brian26

Another observation and based on my monitoring and some research these inverter units definitely have some kind of algorithm to help compressor life. My unit will always start out at the min speed and slowly ramp up capacity in small increments. Starting a conventional AC/Heat pump unit its either on or off at full capacity. That has to be a ton of strain on the equipment and effect equipment life.  These units don't do that even when you try and force them to full capacity by activating the turbo mode.

My unit also has a compressor heating element wrap that will preheat the compressor on cold starts.


----------



## Brian26

begreen said:


> Their head must be up there pretty far. I've been waiting 12 yrs now and what mostly has changed is that the companies that I saw overseas are now owning the market.



Pioneer has a whole house ducted inverter unit with some impressive numbers running a Mitsbushi compressor. 

https://www.pioneerminisplit.com/co...ditioner-heat-pump-system?variant=33504387920


----------



## Ashful

woodgeek said:


> Unless you meant heating DHW....in which case the tech also already exists and is available at HomeDespot with COPs of 3+.  My 6 yo HPWH unit is going strong, but only has a COP of 2 or so.


I check on this every year, and I’m due to check again, but I have never been able to find any HPWH solution that can handle reasonable demand with an indirect system.  Do any exist today?

I’m running an Amtrol Boilermate on my oil-fired boiler, and I’ve asked a few HVAC contractors about adding indirect HPWH to the system, but they all say my system is about the best thing they see, and they woudn’t change a thing.  What they are not acknowledging is the secondary factors, beyond direct operating cost:

1.  The cooling and dehumidification benefits.  My basement is not air-conditioned, but it is finished space that we use.  It's fine thru the first half of the summer, but it can start to get a little warm down there by August.

2.  I’m also burning almost $200/mo in running dehumidifiers down there thru summer, something that would be mostly or entirely offset by the HPWH’s dehumidification.  Those dehumidifiers also pump a lot of unwanted heat into the basement.

3.  My boiler is under our kitchen, and the floor between is not insulated.  The kitchen is already the hottest room in the house in July, between having lots of glass, poorer insulation that adjacent areas, and cooking.  Shutting the boiler down would help keep the kitchen from being warmer than the rest of the house.

Our constraints are primarily very-occasional high usage and long delivery distances.  We have more than ten sinks, four toilets, three showers, two tubs, two dishwashers, and two clothes washers.  I’d bet there are times (holidays/guests) when both dishwashers, a clothes washer, and three showers or a tub are all running simultaneously.  We also have to deliver that water more than 100 feet, in some cases, thru mostly un-insulated copper tubing.

Because of the distance, we have the thermostat set higher than any HPWH can deliver, but that’s mostly a winter thing.  I’d be happy with cooler water in summer, which is when those secondary advantages mentioned above can also benefit me most.  This is why I only consider indirect an option, as I’d be decommissioning it every winter.  Alternatively, if there were one that could be set up in tandem with the boiler to run all winter, that could work... but again, we’re then talking two tanks?

The only indirect systems I found go into the DHW loop on a boilermate, via coaxial dip tube.  This won’t work, as the restriction of going coaxial on the dip tube would kill our delivery volume.  We need at least 3/4” thru the whole system, given the number of simultaneous appliances.  I’d be happy going with a commercial unit, as long as we could find one that’s single-phase on the mains supply.


----------



## SpaceBus

Ashful said:


> I check on this every year, and I’m due to check again, but I have never been able to find any HPWH solution that can handle reasonable demand with an indirect system.  Do any exist today?
> 
> I’m running an Amtrol Boilermate on my oil-fired boiler, and I’ve asked a few HVAC contractors about adding indirect HPWH to the system, but they all say my system is about the best thing they see, and they woudn’t change a thing.  What they are not acknowledging is the secondary factors, beyond direct operating cost:
> 
> 1.  The cooling and dehumidification benefits.  My basement is not air-conditioned, but we have an exercise studio, movie theater, and kids rec-room down there.  They’re fine thru the first half of the summer, but it can start to get a little warm by August.
> 
> 2.  I’m also burning almost $200/mo in running dehumidifiers down there thru summer, something that would be mostly or entirely offset by the HPWH’s dehumidification.  Those dehumidifiers also pump a lot of unwanted heat into the basement.
> 
> 3.  My boiler is under our kitchen, and the floor between is not insulated.  The kitchen is already the hottest room in the house in July, between having lots of glass, poorer insulation that adjacent areas, and cooking.  Shutting the boiler down would help keep the kitchen from being warmer than the rest of the house.
> 
> Our constraints are primarily very-occasional high usage and long delivery distances.  We have fourteen sinks, four toilets, three showers, two tubs, two dishwashers, and two clothes washers.  Setting aside the fourteen sinks, I’d bet there are times (holidays/guests) when both dishwashers, a clothes washer, and three showers or a tub are all running simultaneously.  We also have to deliver that water more than 100 feet, in some cases, thru mostly un-insulated copper tubing.
> 
> Because of the distance, we have the thermostat set higher than any HPWH can deliver, but that’s mostly a winter thing.  I’d be happy with cooler water in summer, which is when those secondary advantages mentioned above can also benefit me most.  This is why I only consider indirect an option, as I’d be decommissioning it every winter.  Alternatively, if there were one that could be set up in tandem with the boiler to run all winter, that could work... but again, we’re then talking two tanks?
> 
> The only indirect systems I found go into the DHW loop on a boilermate, via coaxial dip tube.  This won’t work, as the restriction of going coaxial on the dip tube would kill our delivery volume.  We need at least 3/4” thru the whole system, given the number of simultaneous appliances.  I’d be happy going with a commercial unit, as long as we could find one that’s single-phase on the mains supply.



What do you do for a living?


----------



## Ashful

Research and development.  Am I showing my cards?


----------



## Seasoned Oak

Ashful said:


> of the house.
> 
> Our constraints are primarily very-occasional high usage and long delivery distances.  We have fourteen sinks, four toilets, three showers, two tubs, two dishwashers, and two clothes washers.  Setting aside the fourteen sinks, I’d bet there are times (holidays/guests) when both dishwashers, a clothes washer, and three showers or a tub are all running simultaneously.  We also have to deliver that water more than 100 feet, in some cases, thru mostly un-insulated copper tubing.
> Because of the distance, we have the thermostat set higher than any HPWH can deliver, but that’s mostly a winter thing.  .


You would probably need at least 2 of the 80 gallon models. My 50 Gal HPWH keeps up with a much smaller place and 4 people but i have to set it at max temp which is 140 and for high use times, i set it on hybrid mode so the resistance elements kick in as well to overcome the slow recovery times. The de-humidification does help cut down on the amount of time the regular dehumidifier runs but does not do the whole job.  That said the electric savings MOST of the time is significant.


----------



## SpaceBus

Ashful said:


> Research and development.  Am I showing my cards?



I mean, 14 sinks means you have a huge family and/or a nice job. I now understand how you make all of this energy stuff sound simple.


----------



## maple1

Ashful said:


> I check on this every year, and I’m due to check again, but I have never been able to find any HPWH solution that can handle reasonable demand with an indirect system.  Do any exist today?
> 
> I’m running an Amtrol Boilermate on my oil-fired boiler, and I’ve asked a few HVAC contractors about adding indirect HPWH to the system, but they all say my system is about the best thing they see, and they woudn’t change a thing.  What they are not acknowledging is the secondary factors, beyond direct operating cost:
> 
> 1.  The cooling and dehumidification benefits.  My basement is not air-conditioned, but it is finished space that we use.  It's fine thru the first half of the summer, but it can start to get a little warm down there by August.
> 
> 2.  I’m also burning almost $200/mo in running dehumidifiers down there thru summer, something that would be mostly or entirely offset by the HPWH’s dehumidification.  Those dehumidifiers also pump a lot of unwanted heat into the basement.
> 
> 3.  My boiler is under our kitchen, and the floor between is not insulated.  The kitchen is already the hottest room in the house in July, between having lots of glass, poorer insulation that adjacent areas, and cooking.  Shutting the boiler down would help keep the kitchen from being warmer than the rest of the house.
> 
> Our constraints are primarily very-occasional high usage and long delivery distances.  We have more than ten sinks, four toilets, three showers, two tubs, two dishwashers, and two clothes washers.  I’d bet there are times (holidays/guests) when both dishwashers, a clothes washer, and three showers or a tub are all running simultaneously.  We also have to deliver that water more than 100 feet, in some cases, thru mostly un-insulated copper tubing.
> 
> Because of the distance, we have the thermostat set higher than any HPWH can deliver, but that’s mostly a winter thing.  I’d be happy with cooler water in summer, which is when those secondary advantages mentioned above can also benefit me most.  This is why I only consider indirect an option, as I’d be decommissioning it every winter.  Alternatively, if there were one that could be set up in tandem with the boiler to run all winter, that could work... but again, we’re then talking two tanks?
> 
> The only indirect systems I found go into the DHW loop on a boilermate, via coaxial dip tube.  This won’t work, as the restriction of going coaxial on the dip tube would kill our delivery volume.  We need at least 3/4” thru the whole system, given the number of simultaneous appliances.  I’d be happy going with a commercial unit, as long as we could find one that’s single-phase on the mains supply.



What is your summer oil consumption?


----------



## Ashful

SpaceBus said:


> I mean, 14 sinks means you have a huge family and/or a nice job. I now understand how you make all of this energy stuff sound simple.


For full disclosure, I mis-counted the sinks, there are presently only 12.  You probably also have more than you’d think, until you sit down and actually count them.



maple1 said:


> What is your summer oil consumption?



I’ll need to verify this on my oil tracking spreadsheet, but my memory tells me it’s very close to 1 gallon per day.  Our daily hot water use is probably not all that high, but it can be on occasions when we have guests.


----------



## begreen

Brian26 said:


> Pioneer has a whole house ducted inverter unit with some impressive numbers running a Mitsbushi compressor.
> 
> https://www.pioneerminisplit.com/co...ditioner-heat-pump-system?variant=33504387920


Has to do better than this. The HSPF and SEER ratings are just a tad better than our current American Standard HP. The Mitsubishi unitary Hi-Heat system is more attractive and quieter. 42,000btus at -5ºF. It is however, a whole lot more expensive.


----------



## begreen

This video (and others) may be helpful for someone considering a self-install. What I like about this one is that he got proper training, made a mistake and corrected his mistake properly instead of taking shortcuts.


----------



## Raoul

I didn’t read all the posts here but Costco has this 18k BTU for $1100 if you want to diy. They have other sizes as well.

Mr Cool DIY 18K BTU Mini-Split Heat Pump with WIFI https://www.costco.com/Mr-Cool-DIY-18K-BTU-Mini-Split-Heat-Pump-with-WIFI.product.100409862.html

Also fwiw I paid $14k for a two compressor (4 head) system with a 12 year parts and labor warranty in western WA.
 Not really concerned with ROI as I value the the air conditioning/zone heating.   Also could not stomach the work of redoing the limited ducting in my 1922 home.


----------



## maple1

Raoul said:


> I didn’t read all the posts here but Costco has this 18k BTU for $1100 if you want to diy. They have other sizes as well.
> 
> Mr Cool DIY 18K BTU Mini-Split Heat Pump with WIFI https://www.costco.com/Mr-Cool-DIY-18K-BTU-Mini-Split-Heat-Pump-with-WIFI.product.100409862.html
> 
> Also fwiw I paid $14k for a two compressor (4 head) system with a 12 year parts and labor warranty in western WA.
> Not really concerned with ROI as I value the the air conditioning/zone heating.   Also could not stomach the work of redoing the limited ducting in my 1922 home.



What brand did you get?


----------



## maverick06

Just remember the DIY ones are notably less efficient than the more "professional" units. Mr. cool is 16 seer, Mitshibushi one i had installed is 22 (some go up to 30). Actually, the higher installation costs i plaid WILL be recovered by the efficiency difference.

The big concern i had with the DIY units are the hose management. The spare hose is usually just coiled up next to the unit. Between dogs, kids, weedwackers, etc, I felt that the risk of pinching them (ruining efficiency or ruining the unit) would be high enough that the lifespan of a Mr. Cool versus the mitshibushi wasnt worth it. I figured I would do it once and do it right even though the up front cost was different.  The difference between a 16 seer and a 21 seer makes the 21 seer unit cheaper over a 20 year life (calculated to be a savings of $2200 in energy use over 20 years). Note that when i priced them out, for the size and all i wanted, prices varied by 50%, some companies were just ridiculous (I paid $5 for 15k btu which works down to -15F, the low operating temperature was very important to me)!

Just wanted to point out that you really want to check lifetime costs, not just install costs. Buy a more expensive unit, you can even pay to have it installed, and its going to be cheaper in the long run, all the while you have better equipment to use. Just my experience as someone who paid to have it installed.


----------



## Seasoned Oak

Raoul said:


> I didn’t read all the posts here but Costco has this 18k BTU for $1100 if you want to diy. They have other sizes as well.
> Mr Cool DIY 18K BTU Mini-Split Heat Pump with WIFI https://www.costco.com/Mr-Cool-DIY-18K-BTU-Mini-Split-Heat-Pump-with-WIFI.product.100409862.html
> .


HD had that same brand and size unit for $825.  But it states it should be installed by a trained HVAC. And its 17.7 SEER. 
https://www.homedepot.com/p/MRCOOL-...at-Pump-230-Volt-60-Hz-A-18-HP-230A/300456052


----------



## Seasoned Oak

9 to 12000 seems to be the sweet spot for higher SEER ratings. For some reason.


----------



## peakbagger

Considering that the Home Depot authorized installer wanted about $2,000 over equipment cost to install a dealer supplied Mitsubishi five years ago I hope they have changed the business model .


----------



## Raoul

maple1 said:


> What brand did you get?


For the Multi head unit I got Daikin.  24k compressor running three 9k heads. 

For the basement MIL apartment a single 9k Fujitsu Halcyon.


----------



## Raoul

peakbagger said:


> Considering that the Home Depot authorized installer wanted about $2,000 over equipment cost to install a dealer supplied Mitsubishi five years ago I hope they have changed the business model .


Based on my experience I think the huge labor markup IS the business model.


----------



## maple1

Raoul said:


> For the Multi head unit I got Daikin.  24k compressor running three 9k heads.
> 
> For the basement MIL apartment a single 9k Fujitsu Halcyon.



I got 2 Daikin 12k heads installed in November. My guy swore up and down that each having its own outside unit (2 completely separate systems) was a better way to go than 2 heads on one outside unit. He's good so I just went with his flow, but made me wonder.


----------



## Tegbert

Highbeam said:


> Another night in the 20s. I logged 55 additional kwhs over 24 hours by running resistance heat instead of wood heat. That again checks out to under 8000 btu per hour! I guess my insulation is pretty good when keeping the house just under 70. So 5.50$ in extra energy costs per day of electric resistance heat which is not as high as I would have thought.
> 
> If the minisplit cost 5000$ to install and cuts my resistance heat consumption by 66% (assuming a COP of 3), then I would only have paid 1.82$ so a savings of 3.68$ per day of use. It would take 1,358 winter days of use to cover the installation cost. If I was a non-woodburner and needed to heat on average 180 days per year then the thing would have a 7.5 year break even point. That's not bad if wood heat was flat out banned forever. The equipment should last 10 years. I made an assumption above of 180 days of heat but we really need less heat for a longer time in the shoulder seasons. I also believe that the COP of 3 is rather optimistic when it is below freezing but pretty close on average.
> 
> That last 2.5 years for free only adds up to a reward of 662 bucks. Will I even live here for 10 years? Will it even last for 10 years? Will there be a better technology in 10 years?
> 
> Since I do heat with wood. The only benefit is the 7 days a year or so that burning is banned where the savings would be 25.76$ per year. It would take 194 years to break even.
> 
> I am not going to install the minisplit. They are just too expensive to make financial sense in my situation due to small heating load and cheap power. Resistance heat for the win!



Just thought I would touch base here again. Been extremely busy lately and running out of dry wood I just flipped the breakers back on for the baseboards early February. Boy I wish my house was only $5.50 a day extra to heat with those. With maybe 2 1/2-3 weeks running on this billing cycle I used approximately 153% more energy than last year this time. So $160 more than last month. While it equals out to about $5.30 a day I didn’t have them on the whole month and I’m not entirely sure when I turned them on though so it still may be close to $5.50 a day the whole month having $250 plus electric bills is not entirely fun. I have a feeling though for me it will be between $8-11 a day. 

So in reality I just need to work harder at getting ahead on wood. That bill is definitely motivating for that. 


Lopi Rockport
Blaze King Ashford 25


----------



## maple1

We have an electric boiler for backup heat. I am quite sure it would be $20+ a day if we had to use it full time.


----------



## Raoul

maple1 said:


> I got 2 Daikin 12k heads installed in November. My guy swore up and down that each having its own outside unit (2 completely separate systems) was a better way to go than 2 heads on one outside unit. He's good so I just went with his flow, but made me wonder.



What I do know about having two compressors is one head cannot “disable” the other by being in a different mode.  
I suppose you have a redundant system with your installation.   Are the compressors next to one another?  Maybe he didn’t want to run extra line hide?

I had originally planned on doing all four off of one compressor.   After some discussion we decided to put the apartment on its own system.  That way whatever random Airbnb guest is staying their cannot inadvertently disable the units in my living area. 
They had the Fujitsu at the shop so I went for it.


----------



## woodgeek

On a single polar vortex day, with the split HP running with backup strips....I will use 200 kWh in one day.  $30 from a local wind farm, delivered.


----------



## Ashful

woodgeek said:


> On a single polar vortex day, with the split HP running with backup strips....I will use 200 kWh in one day.  $30 from a local wind farm, delivered.



True”dat.  Our electric bills go up a few hundred dollars in any month we get just a few days of teens or single-digit temps, ever since we installed the mini-splits.  I’m only using them to keep two outbuildings up to 55F, but they can still suck an amazing amount of energy, when it gets real cold outside.


----------



## begreen

Highbeam said:


> Just a matter of time before the conventional split system folks pull their heads out of their butts and improve their equipment to match.
> 
> Also heads in butts for those manufacturers who still haven’t decided to heat water with this technology.


Looks like Gree makes an air to water heat pump. 
https://www.greeonline.com/products/gree-versati-ii-hot-water-heating-systems


----------



## Highbeam

begreen said:


> Looks like Gree makes an air to water heat pump.
> https://www.greeonline.com/products/gree-versati-ii-hot-water-heating-systems



Not in North America it seems.


----------



## begreen

Highbeam said:


> Not in North America it seems.


Hm, same for the Japanese made products. That sucks.


----------



## Highbeam

begreen said:


> Hm, same for the Japanese made products. That sucks.



It’s coming... I know they can do it. Just need enough market.


----------



## woodgeek

I think that NA is a bad market for those.  We have all these high-temp passive hydronic radiators, and the HP can't lift hot enough to run them.  I thought the air to water systems were low temp, with a blower required for going back to heating air...

Does anyone know?


----------



## Tegbert

Tegbert said:


> Just thought I would touch base here again. Been extremely busy lately and running out of dry wood I just flipped the breakers back on for the baseboards early February. Boy I wish my house was only $5.50 a day extra to heat with those. With maybe 2 1/2-3 weeks running on this billing cycle I used approximately 153% more energy than last year this time. So $160 more than last month. While it equals out to about $5.30 a day I didn’t have them on the whole month and I’m not entirely sure when I turned them on though so it still may be close to $5.50 a day the whole month having $250 plus electric bills is not entirely fun. I have a feeling though for me it will be between $8-11 a day.
> 
> So in reality I just need to work harder at getting ahead on wood. That bill is definitely motivating for that.
> 
> 
> Lopi Rockport
> Blaze King Ashford 25



Soooooooooo I’m an idiot. Just thought I would update this again as I was going through all my bills and realized my mistakes. While I did not use the baseboards for a whole month it was not $250. Apparently I missed a payment and that was the month prior and that month. I’ll have to revisit this and do a more in depth watch next winter. 


Lopi Rockport
Blaze King Ashford 25


----------



## Brian26

Been really impressed with my $900 Pioneer cooling performance. I monitor mine with a Efergy electric meter. It was hot here yesteday and here is the usage. At full output it runs around 800 watts and at minimum it runs around 200. You can see it only ran briefly at full output at peak sun around 1-2 and then throttled down.

Easy to see how efficient these are looking at the electric usage graph.


----------



## maple1

So far I've only been using my Daikins on dry mode, and only a couple days - summer has been really slow coming here. They really don't use much juice doing that, I have them both on right now and my effergy is saying 575 watts for the whole house. Should be able to run a/c mode the next couple days to try that, have a heat advisory in effect (one extreme to the other - was the coldest July 1 on record in a lot of places here), supposed to be almost 40c 'feel like' tomorrow.


----------



## maple1

Got our most recent power bill Friday. At about a year after putting our splits in.  Two month billing cycle is about 2 weeks off from when we put them in so not exact, but our bill increased by $530 (at $0.156/kwh usage), total for the year, after the splits. Cut my wood need by quite a bit, I think from 5-6 cords to maybe 3. Haven't got a good estimate on that yet, had some left over but didn't measure it. Not burning during shoulder season means our water heater used more juice which is a part of the extra power used. This year I am trying to burn once a week during shoulder season, mainly for DHW, since the house can use the heat that one day anyway plus the standby loss the rest of the week. Finding it hard to get motivated to start a fire though, when these things just quietly keep us warm for not much $$ with no effort required.


----------



## peakbagger

Thanks for the update. Not sure about your location but last winter in NH was lot colder than prior recent years so your data may need a few years to level out. 

My mini split has gotten a lot of use in the last few weeks. I need heat at night but if its sunny out my place warms up quick so not worth running the wood boiler. My solar hot water system unfortunately doesn't heat my water hot enough on cold sunny days so I end up in squeeze where I would need to run my wood boiler for hot water. My solution is I hooked up an unused backup electric coil on my solar hot water tank last year and flip the power on if the hot water temp is too low.  The SHW does most of the work so the water is already 120 F so the electric coil doesn't have to run for long. That buys me a few weeks before I finally start using the wood boiler.


----------



## Seasoned Oak

Shoulder season is a tough one for wood stoves. Not as easy to turn up and down as most types of heat.


----------



## Ashful

Seasoned Oak said:


> Shoulder season is a tough one for wood stoves. Not as easy to turn up and down as most types of heat.



That all depends on the house, my friend. Stone houses have (literally) tons of inertia.


----------



## Brian26

I installed another 12k Midea myself last weekend. I went with a floor console unit as it is mainly a heating unit. I read mounting heating units low helps a ton with efficiency. I also liked that it could direct air out the bottom along the floor or out the top.  One huge advantage of the console unit is how easy it is to get to the coil and blower for cleaning. Here is the unit taken apart before I installed it. Its literally just a coil and large blower. Even with the lineset attached you can move the coil out of the way easily.


----------



## semipro

Brian26 said:


> One huge advantage of the console unit is how easy it is to get to the coil and blower for cleaning. Here is the unit taken apart before I installed it. Its literally just a coil and large blower. Even with the lineset attached you can move the coil out of the way easily.


Thanks for sharing that.  Cleaning, and maintenance in general, is a major concern to me. 
Maybe its all the furry critters we share out space with.


----------



## maple1

Brian26 said:


> I installed another 12k Midea myself last weekend. I went with a floor console unit as it is mainly a heating unit. I read mounting heating units low helps a ton with efficiency. I also liked that it could direct air out the bottom along the floor or out the top.  One huge advantage of the console unit is how easy it is to get to the coil and blower for cleaning. Here is the unit taken apart before I installed it. Its literally just a coil and large blower. Even with the lineset attached you can move the coil out of the way easily.



One of our Daikins is the same setup. I am really impressed with how it works. Seems quieter, and to distribute better. I think I like the way it works better than the wall mount downstairs. Being able to send the output air in oe or both of two directions is a big plus, especially sending it along the floor if you have cool floors. Ours is right beside where wifeys feet hit the floor in the morning - bonus points there.


----------



## peakbagger

I agree a high wall mount unit is better for cooling but not as good for heating. I notice a distinct stratification of air when running the mini split in heating mode.  I think the average US owner is more concerned with good cooling and regards heating as a nice to have second option so the design is optimized for the typical consumer.  With respect to family pets unless the pet hops up top of the interior unit (most likely feline) there is going to be less fluff  in the air up high than down low. I don't pretend to be able to second guess a cats sense of logic but my guess is sitting on top of something that is making noise is probably not a long term thing but then again I can anthropomorphize the cat  and guess that the cat is doing it to piss the owner off . 

As an aside I am currently going through Siegenthalers Biomass Hydronics course and just finished the section on hydronic emitters. He makes a short reference to using ceiling integrated emitters for cooling (with an appropriate caveat with respect to dew point control) as well as heating. This seems to be a nice setup for a tight house with critters as the during heating season its radiant heat not blocked by furniture and in summer the dense cooler air will drop down and create convective air flow. Since the ceiling is acting as radiant panel there is no filter or works to get clogged up with fur. This obviously only works with air to water type units comparted to the more common air to air.


----------



## Brian26

maple1 said:


> One of our Daikins is the same setup. I am really impressed with how it works. Seems quieter, and to distribute better. I think I like the way it works better than the wall mount downstairs. Being able to send the output air in oe or both of two directions is a big plus, especially sending it along the floor if you have cool floors. Ours is right beside where wifeys feet hit the floor in the morning - bonus points there.



Decided to shoot mine with the Flir. You can really see how these send out some real nice heat along the floor. The insert is in the same room and honestly think I may really only burn in extreme cold.  These things are so efficient and cheap to run its just way easier to set the temp on the remote and enjoy the nearly perfectly maintained heat. I have solar panels as well so you really can't beat the fuel source.


----------



## SpaceBus

peakbagger said:


> I agree a high wall mount unit is better for cooling but not as good for heating. I notice a distinct stratification of air when running the mini split in heating mode.  I think the average US owner is more concerned with good cooling and regards heating as a nice to have second option so the design is optimized for the typical consumer.  With respect to family pets unless the pet hops up top of the interior unit (most likely feline) there is going to be less fluff  in the air up high than down low. I don't pretend to be able to second guess a cats sense of logic but my guess is sitting on top of something that is making noise is probably not a long term thing but then again I can anthropomorphize the cat  and guess that the cat is doing it to piss the owner off .
> 
> As an aside I am currently going through Siegenthalers Biomass Hydronics course and just finished the section on hydronic emitters. He makes a short reference to using ceiling integrated emitters for cooling (with an appropriate caveat with respect to dew point control) as well as heating. This seems to be a nice setup for a tight house with critters as the during heating season its radiant heat not blocked by furniture and in summer the dense cooler air will drop down and create convective air flow. Since the ceiling is acting as radiant panel there is no filter or works to get clogged up with fur. This obviously only works with air to water type units comparted to the more common air to air.



Is there still only one air to water HP unit in the market right now? I like the idea of a unit that does both radiant heating and cooling, best of both worlds!


----------



## Highbeam

SpaceBus said:


> Is there still only one air to water HP unit in the market right now? I like the idea of a unit that does both radiant heating and cooling, best of both worlds!



not even one really. That photo of the coil above drives me batty! Just drop that coil into a tank of water and then use the hot water in your existing low temp heating system.

Do these floorunits cool well? Is condensate a problem due to lack of “fall”?


----------



## Brian26

Highbeam said:


> not even one really. That photo of the coil above drives me batty! Just drop that coil into a tank of water and then use the hot water in your existing low temp heating system.
> 
> Do these floorunits cool well? Is condensate a problem due to lack of “fall”?



Running at full capacity that coil was close to 140 degrees. That could easily heat some water. I have a supply and return temp sensor on it and these measurements are with the fan speed forced to high.


I have a supply and return temp sensor on it


----------



## maple1

Highbeam said:


> not even one really. That photo of the coil above drives me batty! Just drop that coil into a tank of water and then use the hot water in your existing low temp heating system.
> 
> Do these floorunits cool well? Is condensate a problem due to lack of “fall”?



No condensate issues. It still goes down. If it is in a spot that needs to go up (basement?), you just add a cheap condensate pump.

And yes they cool well.


----------



## Ashful

peakbagger said:


> I agree a high wall mount unit is better for cooling but not as good for heating. I notice a distinct stratification of air when running the mini split in heating mode.


I have had several mini split systems with high wall mount units, in fact I still have three in my current place, and this has not been an issue on my systems. They automatically blow the air downward in heating mode, and higher in cooling mode, for stirring and promoting best convection loop in either mode. If your systems don’t do this basic function, you should consider a different brand next time, even the Mitsubishi units I installed ten years ago did this.  I usually leave the air deflector in automatic mode, but you can also manually adjust air direction from the thermostat. 

That’s not to say I’m in love with Mitsubishi, or those ugly wall mount units, they are ugly and have some frustrating limitations. But stratification issues is not one of them.


----------



## Brian26

Finally got some cold weather here and have both splits carrying my full heating load. I have them both hooked up to my energy monitor and its nuts how little power they used overnight.

Right now its in the 30s and both combined are only drawing 625 watts and  are being powered off my panels that are currently producing 4.31 kwhs.


----------



## begreen

That's an awesome start! Keep us posted as winter progresses.

Nice monitoring system too, what is it?


----------



## Brian26

begreen said:


> That's an awesome start! Keep us posted as winter progresses.
> 
> Nice monitoring system too, what is it?



I am using a Efergy monitor.  I may use up all my excess net metered power by Feb but even paying for power its still cheaper than oil.  Power here in CT is really expense around .23-.25 kwh. I wish I had your rates in WA. The EIA has WA at like the cheapest rates in the us at .08 last I checked.
I read they are heavily deploying them in Maine that has really cheap power from hydro like WA.

At those rates these things cost pennies to run. Most 12k splits draw around 1kwh at full output.  Running one for 8 cents an hour is crazy cheap.


----------



## begreen

Brian26 said:


> I am using a Efergy monitor.  I may use up all my excess net metered power by Feb but even paying for power its still cheaper than oil.  Power here in CT is really expense around .23-.25 kwh. I wish I had your rates in WA. The EIA has WA at like the cheapest rates in the us at .08 last I checked.
> I read they are heavily deploying them in Maine that has really cheap power from hydro like WA.
> 
> At those rates these things cost pennies to run. Most 12k splits draw around 1kwh at full output.  Running one for 8 cents an hour is crazy cheap.


You have really geeked out on the instrumentation of this system. I love it. Great info!
8 cents would be Seattle rates. We're more like 11 cents/kWh


----------



## peakbagger

While working on PE credits I ran into a short video course on Heatspring.com. It was about sizing mini splits for cold climate heating. There has been a problem that the standard published data for minisplits tend to be at higher temps.  The published data can not directly be extended to colder temps  and the ratings are also biased towards cooling. A new england energy efficiency group has asked manufacturers for ratings at 5 degrees F and many have complied. The video is worth watching but if you want to go to the listings, hear is the link. https://neep.org/ashp


----------



## DBoon

This summer I replaced a 25 year old Monitor natural gas space heater in a condo with a two-head Mitsubishi hyper-heat mini-split system. After the monthly billing for gas service went to $20 a month, I was glad that the heater just outright failed less than a year later and couldn't be serviced. 

The condo is more comfortable, the noise is almost imperceptible as long as I don't turn them off overnight and then blast them in the morning to reheat. I like these better than the Fujitsu RLS2H (hyperheat equivalent) installed elsewhere.

I'm looking forward to seeing what my heating bill will be this winter. I was paying on average for 70 therms of natural gas per month during the winter (about $100 with monthly service charge tossed in) and I am expecting that these will cost me much less than $100/month in extra electricity. Plus, I won't have to pay a $20 service charge for 7 months a year when I used zero natural gas. 

Some of my condo neighbors talk about $300-400 January or February electric bills running their conventional heat pumps (why I got the natural gas heater 25 years ago). Back-of-the envelope calculation says that I might save nearly $1000/year with these over a conventional system.


----------



## dnewf

I installed 2 senville aura mini splits this summer past 18000k and 12k . One guy here where i live I helped him install a 18k senville last week. He put his 18 inches from the floor because he wants it for heating only. He is amazed the difference at floor level it makes. He also has 2- 12k downstairs running off a 24k compressor but up on the wall. He was inspired by this information he found here on this site. https://www.greenbuildingadvisor.com/question/minisplit-blowers-mounted-low-or-high

I was at his house this weekend past and i was impressed with the heat that was down at floor level and it heats his whole up stairs as well. i will get a few pics when i visit his house again.









						7 Tips to Get More from Mini-Split Heat Pumps in Colder Climates
					

Air-to-air heat pumps are getting more popular as a primary heat source in colder climates. Here’s how to get the most from your system.




					www.buildinggreen.com


----------



## Ashful

DBoon said:


> This summer I replaced a 25 year old Monitor natural gas space heater in a condo with a two-head Mitsubishi hyper-heat mini-split system. After the monthly billing for gas service went to $20 a month, I was glad that the heater just outright failed less than a year later and couldn't be serviced.
> 
> The condo is more comfortable, the noise is almost imperceptible as long as I don't turn them off overnight and then blast them in the morning to reheat. I like these better than the Fujitsu RLS2H (hyperheat equivalent) installed elsewhere.
> 
> I'm looking forward to seeing what my heating bill will be this winter. I was paying on average for 70 therms of natural gas per month during the winter (about $100 with monthly service charge tossed in) and I am expecting that these will cost me much less than $100/month in extra electricity. Plus, I won't have to pay a $20 service charge for 7 months a year when I used zero natural gas.
> 
> Some of my condo neighbors talk about $300-400 January or February electric bills running their conventional heat pumps (why I got the natural gas heater 25 years ago). Back-of-the envelope calculation says that I might save nearly $1000/year with these over a conventional system.



I’m running two Mitsubishi systems, one in a studio above our garage where energy usage is very low, and a dual-head unit in my two-story shop with two overhead doors. The shop unit really sucks some electrons when it gets cold out, those rare weeks we have below 20F with occasional nights sub-zero. In fact, they just can’t keep up in that weather, they spend a lot of their time in defrost mode. Down to maybe 20F they’re fantastic, though... maybe almost enough to make up for what they lack when it gets blistering cold, depending on your climate.


----------



## begreen

Ashful said:


> I’m running two Mitsubishi systems,


What models? HiHeat?


----------



## DBoon

Just checked electric usage since beginning of October. It looks like the mini splits have probably consumed about 200 to 250 kWh of electricity to heat 1200 square feet of space through 600 degree days. That's about $25 to $30 or so of electricity. My old basic gas service charge was $20/month and I probably would have consumed about 30 therms of gas at about $1/therm, so I'm looking at about half the heating cost so far during these moderate, fall temperatures.


----------



## Brian26

Here is a good graph on how good a mini split can maintain an exact perfect temperature. The air was bone dry (outside dewpoint of 9) here so I switched over to oil to run the whole house humidifier.

Notice the perfectly maintained 67 degrees overnight and then the wild swings of the furnace when it went on around 8am

These things are amazing for running super quiet at only the btus required for the heat loss.


----------



## begreen

That hysteresis is pretty normal when taking a space up 5+ degrees, even for a mini-split. The oil burner heated up the place quickly and shut off as the thermostat was satisfied. But the actual room mass and contents had not warmed up fully, just the air. Once all the chairs, sofas, walls, floors, etc. are up to temp, those temperature swings should be much less, even with the oil burner running, depending on the swing setting of the thermostat.


----------



## Brian26

I ran both my mini splits for pretty much the entire month of November set to 70.  The results were impressive considering Nov was a really cold month here. I did have a fire or two but have been finding that mini splits do very little to indoor winter humidity so I have been having less fires. Every time I have a good hot fire its crazy how fast my indoor humidity drops. My wife is very sensitive to dry air.

I monitored the electric consumption of both my 12k splits. They average around 6 kwhs a day it seems and combined consumption was 448 kwhs. I have solar panels but at CTs electric rates of .20 a kWh it would have cost $89.60 for the month.  The national average is like half that so many would cut that in half. Seems like a bargain for leaving the tstat at 70 for the month.


----------



## Alexx

Mini split does not have to be a ceiling cassette or a head high on the wall. They make indoor sections that sit near the floor-makes sense to me if the primary objective is heat and they aren’t in my line of sight.

2 ton conventional ACs or Heat pumps use 12 gage wire circuits too.


----------



## Brian26

Alexx said:


> Mini split does not have to be a ceiling cassette or a head high on the wall. They make indoor sections that sit near the floor-makes sense to me if the primary objective is heat and they aren’t in my line of sight.
> 
> 2 ton conventional ACs or Heat pumps use 12 gage wire circuits too.



I have a floor console unit. Its superior to my wall unit downstairs in heating. The big advantage is the return air sensor is measuring the air a foot or 2 above the floor. Wall units are measuring the much warmer air temperature just below the ceiling height.  The floor console units are also drawing the air in from the floor. The performance is stunning. The air outlet can be set for top or bottom or both. It puts out great warmth across the floor. Here is a flir shot of the unit in operation.

2nd one is the air sensor located just above the string on the door.


----------



## maple1

Yup. Another +1 here for floor mount units, one of our 2 Daikins is floor mount. I think our high mounted wall mount unit certainly works well, but it makes more slight air currents that you might sometimes end up sitting in and can feel a bit chilly even if they really aren't. 

Some also have mounted their wall units down low for better heating feel.


----------



## Brian26

maple1 said:


> Yup. Another +1 here for floor mount units, one of our 2 Daikins is floor mount. I think our high mounted wall mount unit certainly works well, but it makes more slight air currents that you might sometimes end up sitting in and can feel a bit chilly even if they really aren't.
> 
> Some also have mounted their wall units down low for better heating feel.



Its also pretty amazing how good they can regulate a constant near perfect temp. I have a return air and supply temp sensor on mine. It just locks right on the setpoint and maintains it perfectly.

Here is the supply/return temps when I had the unit  turn on at midnight set to 69 degrees.


----------



## Seasoned Oak

The ceiling units are the best looking as long as the blow the heat down to the floor.  
https://www.mitsubishicomfort.com/e...onal+|+EZFit+|+1.13-3.31&utm_term=EZFit-Green


----------



## peakbagger

One thing for folks with pets to consider. A floor mount is far more likely to collect per hair and also for some reason is also a popular spot for cats to perch on (No clue why but then again we are talking about cats  ). The units have filters that can be cleaned so it just means upping the maintenance. I expect the recessed ceiling unit is probably the safest option from a pet hair perspective. Somewhere I ran into a comment that a cat had decided that the top of standard high mounted wall unit was a perfect perch to survey its domain. The system was not working well so a tech was called. The tech found a unit that barely would flow any air. He opened up the case and the filters were packed solid with fur.  

For those who are tenants of a house owned by a cat, they may want to consider making the top of these units per unfriendly ( Pigeon Spikes ?)  and keep an eye on the fllters.


----------



## Brian26

The floor units are 10 times easier to clean and take apart.  The coil is completely exposed. The coil can  also be easily be moved out of the way to access the fan. The refrigerant lines dont need to be removed. Wall units require special cleaning hoods and the flong fan wheel can be a nightmare to acess and clean.  The floor units use an actual round fan blade.

A ceiling unit would be great for cooling but in heating mode it would be drawing in the hottest air at the ceiling level. All the cold air is going to sink to floor level. The colder the air intake the efficiency goes way up. I have a wall unit as well and the floor unit blows it away in heating mode. The floor level is way warmer than where the wall unit is.

On my house central air all the returns were at the floor level. I installed new inlets with dampers at the top of the wall. The difference in cooling was staggering as I was now drawing in the hottest air.  In heating mode I use the floor returns. The results were impressive.


----------



## Seasoned Oak

I agree efficiency wise the floor units would work better for heat , but i go out of my way to keep from cluttering the walls with appliances if possible  The best case scenario (for me)is a heating and cooling system you cant easily see.  For hydronic systems i like the cabinet kick panel heat exchanger.


----------



## peakbagger

Off on a tangent are John Siegenthaler's radiant heating and cooling walls and ceilings where there is no evidence of any heating or cooling system. They line up well with the cold climate air to water units (if and when any of the big boys decide to start selling existing product into the US market). I will gladly run glycol around but far less comfortable moving refrigerant. I will agree the cooling aspect is scary as dewpoint issues can cause mold but many commercial studies show that if its a tight building with no vapor sources, radiant cooling can work.  The cooling aspect is definitely "bleeding edge" for a home system but perfect for wood systems with storage as the supply temps for heating are about as low as anyone can get meaning far more effective storage capacity.


----------



## Highbeam

Seasoned Oak said:


> The ceiling units are the best looking as long as the blow the heat down to the floor.
> https://www.mitsubishicomfort.com/ezfit/?campaign_id=31175&fbclid=IwAR2n7C8L85g3kVWw1E1SgxcWuooZMRE11WC4gG-Rvg0NiQN512ZCCvOyWW8&utm_source=Facebook&utm_medium=paid&utm_campaign=Comfort+|+Facebook+|+Website+|+National+|+EZFit+|+1.13-3.31&utm_term=EZFit-Green



Warning, opinions to follow! This is highly subjective stuff. 

Those ceiling cassettes look just like the ceiling mounted AC units in RV trailers. Like actual trailer trash. Further, their efficiency was way lower and cost much higher than the wall units. 

The "best" looking units are the ducted ones. They can be hidden in a closet, attic, or below the floor and all that you see is a conventional HVAC grill.


----------



## Alexx

Seasoned Oak said:


> The ceiling units are the best looking as long as the blow the heat down to the floor.
> https://www.mitsubishicomfort.com/ezfit/?campaign_id=31175&fbclid=IwAR2n7C8L85g3kVWw1E1SgxcWuooZMRE11WC4gG-Rvg0NiQN512ZCCvOyWW8&utm_source=Facebook&utm_medium=paid&utm_campaign=Comfort+|+Facebook+|+Website+|+National+|+EZFit+|+1.13-3.31&utm_term=EZFit-Green



The ceiling units can look good, but i think if you check the efficiancys the different head units have differences.  Any sort of duct work changes things quickly.  Might not matter much but those wall units are the most efficient and one outdoor unit to one head is the most efficient set up. Those multi head systems also leave some things to be desired, redundancy, efficieny, simplicity, sound.


----------



## Ashful

It used to be those Mitsubishi ceiling units were cooling only, no heat.  Have they changed them to also do heating?


----------



## peakbagger

I review various proposals for VRF (Variable Refrigerant Flow) based systems on occasion. The household multihead systems are usually a simple VRF design. On the commercial systems, the air handlers have a coil and drain in them so they can go either heating or cooling and are sold in lots of different configurations including the low mounts, the high mounts, inline duct mounts and other configurations.  They typically are custom systems and need to be engineered. The original high ceiling mounts were optimized for predominantly cooling as they came out of Japan where the population is concentrated in warmer regions of the country.  A typical Japanese home is cramped so a high mount is a better fit than a low mount.  

An engineered system typically means its going to be higher cost to install and for most people on a budget mini splits are already too expensive. Sure if someone is building  or remodeling a new expensive home where cost is less of an object, there probably are a lot of alternatives but to someone with a 100K home that have a tough time scraping up money to replace a window unit so they dont broil in the summer, a 3 K minisplit is already a tough sell. My guess is there is premium for even the low mount unit and definitely an install premium for a ceiling unit. There is lot of competition starting to pop up on commodity minisplit installs so I expect some dealers are differentiating themselves by selling premium offerings like multiheads and alternative indoor heads. They make most of their money on manpower so a complex install requires more manpower and makes more profit. I expect if you look at $ per BTU produced the cost per BTU for complex system is higher on unit basis.


----------



## Brian26

If you know how to install one a single head unit is pretty much a cheap disposable appliance in my opinion  and its like that in most of the world. Costco and Walmart sell  them for a couple hundred bucks in Mexico. I read it cost $50-100 there to have one installed. 

My Midea 12k Hyperheat was $1k shipped to my house and it came in a  Midea Carrier North America box with both Carrier and Midea stickers you put on yourself. If it  blows up I can still buy 3 more and be ahead of a professional install. 

I have noticed alot of off brand names around here so I suspect someone is doing these on the side for cheap.


----------



## peakbagger

If and when EPA gets serious again abut HFCs I expect they will tighten up on who can sell and install. Ozone depleting chemicals were tracking downwards for quite few years but have bumped up of late as there is lot or third world use and abuse so CFCs and HCFCs. I expect most folks just vent the gas when they remove them compated to recycling it. 

Odds are the next generations of these will use propane for refrigerant.


----------

