Want a Wall Mounted Ductless Heat Pump

kadini · 3:19AM

Pictured above is the south wall of our living room. Between the fireplace and the corner cabinet (only place in the house it works) and above the painting (print) is approximately 66" X 22". This is an exterior wall (second story) adjacent to the driveway and there are no obstructions on the outside. The electrical panel for the house is on the same side of the fireplace downstairs.

Like to put a self contained (not split if possible) ductless heat pump in that space. Thinking the heat pump will occasionally cool the living room (about 22' X 20' with a vaulted ceiling) a few days in the summer and take a load off our recently repaired central heat electric furnace in the winter. The house currently has heat but not AC,

The wall must be load bearing, don't see how it can't be. So any cutouts either have to work around the studs or otherwise be reinforced to compensate for losing vertical load capability. The outer wall is some kind of 1970s insulation board covered with wood siding.

We had our electric panel replaced a couple of years ago and they gave us an external conduit for a possible hot tub on our deck. So getting power to the unit should be easy.

For BTU calculating purposes we thinking doubling the square footage of the living room (at least) is in order as it is open to the kitchen, the hall to the bedrooms, and the stairs down to the entrance way. In other words we are hoping to cool the kitchen too and a great deal of the cold air will certainly go downstairs. But our electric furnace has a summer fan switch specifically for recirculating the always cooler air from downstairs through out the house.

If we have to go split the outside component will likely have to be mounted up off the ground above the driveway and the extremely incompetent drivers who inhabit the premises.

Like for the panel and vents on the inside wall to not stick out too far like a typical floor mounted hotel unit does. The space is there but it's an aesthetic consideration. Mounting a unit in the ceiling is not possible as there is no empty space above the vaulted ceiling. Mounting on the floor would displace my stereo cabinet.

Open to all advice and suggestions.

Thanks!

bburd · 3:39AM

Have you considered adding a central heat pump to your existing electric furnace? That would give you much more efficient heating and full central cooling, would be much quieter than a thru-wall unit and would be invisible from the living room.

If that is a gable-end wall on a 1970s house it is probably not load bearing since the roof load is usually carried by the longer exterior walls. A licensed builder, architect or structural engineer can tell you.

kadini · 6:04AM

The estimate to replace electric furnace with an air handler and put a heat pump outside the north wall that would heat cool the whole house was $$K.

We haven't really needed AC for most of the 23 years we've lived in the house. Only a few days each summer but it seems like there are more of them each year.

We think we can do the ductless for less than $$k. Maybe substantially less. And we are confident that will lower our heating bills which have also been getting higher.

So yes we looked at central air and heat with a heat pump. It's too much money. My neighbor is a contractor he can tell me if the wall is load bearing but I'm 99% positive it is.

You're right though the $$k solution would be quieter.

HVACNUT · 2:43PM

Load bearing or not, only a 2.5" hole needs to be drilled through the wall for refrigerant pipes, electric, and drain. The head doesn't weigh much, so that's not an issue. It WILL be a split system with one indoor head and one outdoor unit mounted above the snow line.

At approximately 440 sq ft, without knowing the climate zone, insulation, and ceiling height, we can't give an accurate calculation on what size. But on the second floor with a vaulted ceiling, I might opt for a 12K, knowing it will modulate. 9K if there's a ceiling fan and a cool climate zone.

kadini · 3:02PM

Sorry climate zone is Seattle. I should have said that before.

We looked at whole house central heat pump replacing electric furnace. $$k

Keep the furnace and have a split units with 1, 2 or 3 ceiling mounted (wall mounted in living room) heads $$k, $$k and $$k respectively.

They all entailed having the heat pump on the north end of the house on the ground away from the driveway. Did say mounting the unit on the outside wall above the driveway was an option.

Basically the unit cannot sit on the driveway even though it's mostly in the shadow of the fireplace.

Is split the only option? If so any suggestions? Brand model etc.

pecmsg · 3:06PM

No one can GUESS at sizing! An accurate manual "J" heat load / loss is the only way of knowing the correct size.

Once the size needed is determined then the installing contractor is the most important decision. A bad install leads to early and costly failure.

kadini · 5:54PM

Let me start over.

We bought 2 Hisense portable 115v 9000 btu heat pumps to cool 2 upstairs bedrooms during the summer. They work great. Kind of a pain as they take up a lot of space and ties up a window but for short term summer use it works

Below is pictured an experimental set up of one of those units in my large un-insulated garage hoping I could get the temp in there warm enough to work on my project car during the winter.

The unit requires a 115v outlet and and external inlet and outlet ducts.

Plus I had to rig up a drain to outside. Heating fills the onboard tank up in maybe 15 minutes so continuous draining is needed. When we use the units inside for AC the units sit on the floor and the onboard condensation tanks have never needed draining for at least the last 2 summers.

Long story short in ambient temps as low as 40 deg F the unit would heat the garage to 66 deg, the lowest heat setting available. And it will keep the temperature there. Experiment was a smashing success. If I decide to permanently heat my garage I will move the unit elsewhere and cut holes in the wall. The garage is my sandbox.

Fast forward a few months. Our furnace failed. I put one of these units on a table in the dining room/ kitchen. It was set up exactly the same as the garage except higher up so I could run the drain through the bottom of the window and not drill a hole in the wall.

Long story short it kept the kitchen/dining room warm plus the living room using a fan to blow air out there. Didn't do the rest of the house of course, and I understand the hot air tends to stay up as opposed to going down stairs which is what the AC cold air would want to do.

And, we could use a unit like this to cool the living room but we can't make the space needed for it, next to the front windows, unlike in the bedrooms. Plus there's the drainage issue if we wanted to use it to heat.

But, what if I built a shelf in the area I want to put the ductless heat pump, set the Hisense unit on that shelf, cut holes for the ducts and the drain? That would work but the Hisense unit doesn't fit the space being about 30" X 20" X 18".

Or I could build an external cabinet sealed so it's part of the internal house volume with a slot cut to let the air in. Have to get on a ladder to clean the air filter. Not real worried about external aesthetics in that area as it's right above where the garbage cans go.

Or I could buy a hotel style floor mounted self contained heat pump but then my stereo has to move and there's no place for it to go.

The Hisense units were about $300 each. Surely there are wall mounted units available that will do this? Think like a window mounted AC except it's a heat pump. And come to think of it why don't they make something like that anyway?

I am sure I can find a solution. But was hoping to leverage off the knowledge and experience on this forum. A relatively flat head (panel) that fits the 22" X 66" space available with a small split unit (heat pump) hanging off the exterior wall above the garbage cans is all I need. Or a compact self contained unit similar to the Hisenses would be good too. Not having to rearrange studs is obviously a big plus.

Looking for the cheap solution. Increasing the btu to 12,000 gives me some extra margin, having too little is worse than too much. And I feel confident it will at least cool the living room in the summer and heat in the winter, i.e. lower our heating bills.

Now what do you say?

ChrisJ · 7:08PM

A non-split unit is called a window unit, window shaker etc.

You have splits, mini splits, and window units. Well, and those horrible portable units that blow conditioned air outside (pulling in a good amount of non-conditioned air from outside into the living space).

You have duct work, I'd go with a ducted air handler.

HeatingHelp.com · 7:54PM

Hello @kadini , one of the rules of the forum is to not post job pricing/estimates. I've edited those numbers out of your posts for you. Thanks, Andrew

jimna01 · 8:06PM

I will

Add one more type to ChrisJ’s list. A package unit.

kadini · 8:18PM

My apologies for posting the pricing numbers. They were approximate.

Want a Wall Mounted Ductless Heat Pump

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