Alternative heat source, minisplits for real?

[Tegbert]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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.