# Need opinions on mini split



## toadman77 (May 28, 2015)

Hello.  I had a 18000 hyper heat mini split installed this past fall in my living room.  I am very impressed as my electric  bill has been so much cheaper.  What I need help on is adding some more heat to the rest of the house when its in the low teens and below and to give the 18000 unit some help during defrosts and so maybe help the cop. My house has all electric radiant heat until that addition except the basement which has no heat and has quite a bit of moisture from no heat.  Temps in the basement can get down to 42 ish and it mostly underground.  i thought of a few options and looking to see what would be the best.  I attached a rough drawing of the main floor to give an idea and where the current unit is at.  I sized the 18000 unit due to being the hardest to heat and the extra heat for the negative temps.  AC is not an issue since the house is cool in the summer.  Location is south west pa.

First is just put a  hyper heat or fugitsu .75 ton unit in either the spare bedroom to push heat out to the back of the house though I'm not sure if its worth doing since the bathroom and bedroom are not bad .  I use a box fan to push the air out of it to the living room.  Or I could put it in the dining room to push the air to the kitchen where it was chilly.  The unit could be either a floor or mounted near the floor on the opposite wall of the kitchen walkway.  Other idea though I don't  think it would help the main floor is mount it in the basement.  These units have around a 13.5 hspf.

Next option is do a 20000 hyperheat  dual mutizone unit. If I do that I would have to decide which one of the three areas don't get one.  10 hspf

Last option is a 24000 hyper heat tri unit.  I could heat all those areas buts its going to probaley cost $1500 more I really don't think its worth it.  10 hspf  

Any ideas would be welcome.  I also don't have natural gas or ductwork in the house.  House and insulated really good but need to replace a few windows eventually that are older but double pane.


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## begreen (May 28, 2015)

Normally one puts the heat where folks spend the most time. Putting it in the dining room pointing toward the kitchen seems to satisfy that need. I would space heat the other areas. Is the basement fully insulated?


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## Grisu (May 28, 2015)

How about adding a woodstove?


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## toadman77 (May 28, 2015)

The basement  does have insulation in the rafters and half the walls are  down.  I don't know how effective  It is because of the moisture. I  don't know if it's worth  putting  a unit there or not.


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## toadman77 (May 28, 2015)

Wood stoves are nice but not something I don't wanna deal with Between getting wood and ashes. Thanks for the idea though.


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## begreen (May 28, 2015)

The reason I asked was thinking whether heating the basement to warm up the floors and keep it drier would be worth considering. What is the source of moisture in the basement? Condensation, poor sealing, rain water not being diverted properly, low water table? Do you run a dehumidifier down there now?

An alternative to a wood stove might be a pellet stove?


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## toadman77 (May 28, 2015)

Once in a while i get a little water  from a big storm. I run a dehumidifier during the summer months but the rest if the year it doesn't pull much water out probably because it's chilly . If one was to be installed  would you wanna take out all the insulation in the rafters?


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## begreen (May 28, 2015)

If there was heat in the basement and it was kept warm then yes, I would remove the basement ceiling insulation and insulate the walls. But first I would address the source of water coming in. Sometimes this is a simple as cleaning gutters and directing the output from the downspouts a few feet away from the house. Sometimes it is more complicated needing a french drain installed on the upslope edge of the house.


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## toadman77 (May 28, 2015)

I  know there's an outside French drain  and the water runs away from the house.  Its only a couple times it happens.  Would you do a dual unit or do two separate units.


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## begreen (May 28, 2015)

Based on the little I know about the house and how it's used I would probably go for the higher efficiency unit in the dining room and space heat the bedrooms. This is assuming there is little need for the basement for anything but storage.

Question: Are power outages very rare in your area?


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## toadman77 (May 28, 2015)

Thanks for the help.  I'm goin to look at either a .75 ton hyper heat heat or a fugitsu  .75 ton  floor model which would look better in there.  Between the two that should be around 25000 btus after defrost and any loss of heat under 5 degrees.


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## toadman77 (May 28, 2015)

I forgot to ask do you think they would interfere with one another?


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## begreen (May 29, 2015)

No. Also look at Mitsubishi equivalent for great low outdoor temp performance.


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## maple1 (May 29, 2015)

begreen said:


> No. Also look at Mitsubishi equivalent for great low outdoor temp performance.


 

hyper heat = Mitsu.

I think?


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## Highbeam (May 29, 2015)

maple1 said:


> hyper heat = Mitsu.
> 
> I think?



Yes, mitsu is hyper heat. The multi head units cost way more and are lower efficiency. Singles are better for the additional benefit of independent systems so if one dies the other still works.


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## maple1 (May 29, 2015)

I'm pretty close to going to get an estimate from the local Mitsu people. Many more hot days like yesterday (hot to me anyway) and might be a done deal. The dual head has my attention, it would work pretty good for what I have in mind I think, despite the bit of a hit in efficiency- but will run thru the choices with them when I do get to talking.


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## toadman77 (May 29, 2015)

I did see they got muti zone hyper heats.  There about a 10 hspf. My single unit I have now is 10.3hspf. The new single zone hyper heats get up to 13.5 hspf.


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## toadman77 (May 29, 2015)

Post back with what they tell you about the multi zone.  Supposely there compatible with a whole bunch of inside air handler  units.


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## toadman77 (Jun 7, 2015)

I was wondering has any  one tried the ducted unit?  I'm assuming you would need a return  duct and was wondering how it monitors the temperature since it would be goin to separate areas.


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## begreen (Jun 7, 2015)

I almost put one in back in 2006. Unfortunately no one had installed one yet in our area and the only brand sold was a Sanyo unit. I ended up installing a high-end American Standard with a variable speed air handler instead. Now there are lots of choices and I wouldn't hesitate to try one. Yes, it will need return(s) ducted in. Temperature is monitored and the unit is controlled by a wired or wireless remote thermostat(s). The main limitation is size. They don't make them in 36,000 btu units so for our house we would need two. 

This site has pictures of several ducted mini-split installations:
http://homeenergypros.lbl.gov/profiles/blogs/what-do-ducted-mini-splits-look-like


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## Highbeam (Jun 8, 2015)

I was told that the remotes don't actually monitor temperature but the unit itself so you would want to be sure that the return air is taken from the room(s) you want to heat/cool.


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## STIHLY DAN (Jun 10, 2015)

you can have wired remote, or wireless and take temp from either unit or t'stat. there are 2 types of ducted units. 1 is like a traditional unit but has same modulating condenser, then there are horizontal skinny units that have to be ducted towards static pressure.


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## toadman77 (Jun 12, 2015)

I was wondering how the ducted  worked. I think I'll  stay with the other. I'm thinking of a fugitsu  floor model over Mitsubishi  a wall unit.  It's about a $150 more. It still does  negative temps to. I would  probably use it more during the off seasons since the 1.5 ton short cycles  a lot during the 50 and up days.


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## STIHLY DAN (Jun 12, 2015)

These don't short cycle they modulate. They are at the most efficient at 47*


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## toadman77 (Jun 23, 2015)

I read somewhere that they short cycle and it's hard on the unit.  Adding a second unit should bring the cop up in the winter I would think.


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## begreen (Jun 23, 2015)

I haven't seen that with the units in our area. Maybe an installation or setup issue?


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## toadman77 (Jun 24, 2015)

I think it's because the minimum is 7500 btus and i don't need that much when its milder out. I'm just wondering if it hurts the unit.  Adding the second one I would be able to leave this one off  till it's colder outside


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## begreen (Jun 24, 2015)

The usual reasons that could cause short-cycling are very rapid heat loss, thermostat poorly located or with a mis-set swing range or defect.


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## toadman77 (Jun 24, 2015)

I usually  put it on wide  vane  do heat travels toward the hallway and the lowest  setting to push the heat to the floor. I didn't purchase an external thermostat. I don't have it happening  when it really cold out.


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## begreen (Jun 24, 2015)

Maybe a remote thermostat in the hallway would help? Or can the swing setting (differential) for the internal thermostat be increased?


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## johnhartsell (Jun 26, 2015)

A wood stove, I feel, is not that great an idea as it increases the expenses. I had a similar problem and my air conditioning company nj recommended me to go for a good quality of thermostat. Thermostats do work well if you can get the right one.


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## maple1 (Jun 26, 2015)

_*A wood stove, I feel, is not that great an idea as it increases the expenses.*_

What method of heating doesn't increase expenses?


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## johnhartsell (Jun 26, 2015)

maple1 said:


> What method of heating doesn't increase expenses?


Well I didn't mean that only wood stoves increase expenses. There are various kinds of expenses and investments associated with all heating techniques. Even thermostats are expensive but they are, in my opinion, a one-time investment and a better alternative to wood stoves. Its the digital world and a bit of gadget-friendliness won't do any harm.


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## maple1 (Jun 26, 2015)

I think you've lost me on thermostat vs. wood stove...


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## georgepds (Jun 29, 2015)

toadman77 said:


> I read somewhere that they short cycle and it's hard on the unit.  Adding a second unit should bring the cop up in the winter I would think.


 
The new high efficiency units do not short cycle.. they have a variable speed compressor


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## toadman77 (Jul 7, 2015)

I researched and found out the floor models need mounted 6 in off the floor.  How could the piping be hid without opening the wall up?


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## georgepds (Jul 14, 2015)

toadman77 said:


> I researched and found out the floor models need mounted 6 in off the floor.  How could the piping be hid without opening the wall up?


 
If you're talking abount an air source heat pump.. the answer is the fluid and electric lines go through the wall behind the inside heat exchanger . The lines are then routed outside to the exterior heat exchanger (compressor)


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## peakbagger (Jul 14, 2015)

The standard install is to drill a hole through the wall behind the unit and run a vinyl "gutter" down the outside of the house to the unit. The gutter has a baseplate you install on the exterior wall and the power, refrigerant  lines and drain are then strapped to it with tywraps, then a top cover snaps over it. The refrigerant  lines are insulated with black rubber that can deteriorate in the sun so it has to be covered. If you have a thick wall you can fish the lines through a chase in the wall but an installer will charge extra as its a lot more work. Incidentally make sure to seal off the cables and tubing as it enters the wall with foam as otherwise you have an open hole to the outside in the wall.


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## Mpodesta (Jul 14, 2015)

Just has a 12k unit installed, best investment i have made, house feels wonderful!


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## toadman77 (Jul 15, 2015)

What i want to do is  run it straight down  through the floor  then go through the basement to the outside like the other unit.   I was wondering if I have to have it exactly six inches off the floor or can it sit on the floor. If i do mount it six inches the piping will be seen in the room and have to hide it. My wall mount unit has the pipes running in a closet but can't do that on this install do that's why I'm figuring  on a fugitsu floor  mount  and do straight down into the floor .
I'm  planning  on doin must of the work except  for vacuuming and electrical.  

Glad you like it.  Are you planning on using  it for heating in the winter?


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## STIHLY DAN (Jul 15, 2015)

toadman77 said:


> What i want to do is  run it straight down  through the floor  then go through the basement to the outside like the other unit.   I was wondering if I have to have it exactly six inches off the floor or can it sit on the floor. If i do mount it six inches the piping will be seen in the room and have to hide it. My wall mount unit has the pipes running in a closet but can't do that on this install do that's why I'm figuring  on a fugitsu floor  mount  and do straight down into the floor .
> I'm  planning  on doin must of the work except  for vacuuming and electrical.
> 
> Glad you like it.  Are you planning on using  it for heating in the winter?



The Daikin can be floor mounted.


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## Mpodesta (Jul 15, 2015)

toadman77 said:


> Glad you like it.  Are you planning on using  it for heating in the winter?




Than plan is to use it in conjunction with the pellet stove. It's installed part way up the stairwell between the two floors, hopefully it can help pull some of the heat from the stove downstairs, up. Not to get off topic, but we are in negotiations on having a 5kw solar system put in, which should provide us with "free" cooling an supplemental heating with the mini split


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## peakbagger (Jul 16, 2015)

You will be happy with a solar/minisplit set up, I expect you will use your pellet stove less. I know I have cut back on my wood boiler use.


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## toadman77 (Jul 17, 2015)

Is floor  mount on the floor or up of the floor?


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## Highbeam (Jul 17, 2015)

Great thread folks. Goes to show how little we all know about the nonstandard minisplit options.


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## dougstove (Sep 30, 2015)

In this thread  people commented that the multi-head Mitsubishi HyperHeat (Mr. Slim?) units are less efficient than single head units.

I have two small (~11' x 10') bedrooms downstairs that do not get heated well from my woodstove.

The smallest indoor head unit I see in Mitsubishi Hyper Heat spec sheets is 6700 btu/h at 17F.  My heat need in the bedroom would be 5000 btu/h or less.

Would it make sense to get a the small head unit in each room, both connected to a single outdoor unit?
Do they run well below maximum capacity?  Most of the time my heat requirement would be 3000 btu/h or less, I think.
Do they have a decent dehumidification mode?
I do not need air conditioning, per se, but I could use summer dehumidification.
cheers, Doug


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## toadman77 (Sep 30, 2015)

I'm  not  sure of your setup but you could have a few options.   Putting a muti head unit might be too much for the area.   The minimum load  if I remember right was around  7500 btus.  A single head unit will have a lot less btus on minimum load  (1700btus).  You could use a floor  fan to help push the air in the other roomor mount it do it could blow directly through the door  way.  
Also look at Fujitsu units as they got a nice floor mount and works even in lower temps. A single head unit would push 3100 btus at minimum but its mounted on the floor and should need the extra btus. Other  plus is no matter which size you get there all rated  for the minimum 3100. Knowing this now I would've got a fugitsu for the living room since  it wouldn't short  cycle.

The hyper heat  I have does a great job dehumidify   the air but the drawback  is the room  gets to cold  if it runs  a few hours since the heat  is exhausted  outside.


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## STIHLY DAN (Oct 10, 2015)

toadman77 said:


> Is floor  mount on the floor or up of the floor?



You can install either way. Floor mounts also can blow air on the floor and in the air.


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## toadman77 (Oct 10, 2015)

STIHLY DAN said:


> You can install either way. Floor mounts also can blow air on the floor and in the air.




I installed  about  and inch above so if I want  to change the carpet  or do flooring it has room to be worked under.


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## toadman77 (Oct 10, 2015)

I do have a question. Does anyone have the external thermostat hooked to the mitibushi wall units?


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## STIHLY DAN (Oct 10, 2015)

Yes. what is the question.


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## Highbeam (Oct 12, 2015)

STIHLY DAN said:


> You can install either way. Floor mounts also can blow air on the floor and in the air.



So do these floor mount, or low wall mount, units run the coolant and drain lines out the back into the wall or down through the floor?


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## toadman77 (Oct 12, 2015)

Either way for the lines.   My wall mount and floor mount run down under the floor and through the rafters outside. I did not want to have the lines seen  on the outside or in the living  area.  There mounted on inside  walls also.  The condensation lines are also ran in the basement to a drain.   I the wall mount is installed on a closet wall so the pipes are hidden.  A little planning and they  are pretty flexible in placing.


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## begreen (Oct 12, 2015)

A friend up north is looking into having mini-splits with the floor units installed. If they go for it I will go up and take pics of the installation.


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## STIHLY DAN (Oct 12, 2015)

Lines can go down through the floor, out the back, or out the side.


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## toadman77 (Oct 13, 2015)




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