Want a Wall Mounted Ductless Heat Pump
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!
Comments
-
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.
—
Bburd0 -
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 $$$$$$k solution would be quieter.
0 -
Load bearing or not, only a 2.5" hole needs to be drilled through the wall for refrigerant pipes, electric, and drain. The head doesn't weigh much, so that's not an issue. It WILL be a split system with one indoor head and one outdoor unit mounted above the snow line.
At approximately 440 sq ft, without knowing the climate zone, insulation, and ceiling height, we can't give an accurate calculation on what size. But on the second floor with a vaulted ceiling, I might opt for a 12K, knowing it will modulate. 9K if there's a ceiling fan and a cool climate zone.
1 -
Sorry climate zone is Seattle. I should have said that before.
We looked at whole house central heat pump replacing electric furnace. $$$$$$k
Keep the furnace and have a split units with 1, 2 or 3 ceiling mounted (wall mounted in living room) heads $$$$k, $$$$k and $$$$$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.
0 -
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.
0 -
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?
0 -
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.
Single pipe 392sqft system with an EG-40 rated for 325sqft and it's silent and balanced at all times.
0 -
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
Forum Moderator
0 -
-
My apologies for posting the pricing numbers. They were approximate.
0 -
I do not believe my Hisense 2 duct portable ACs waste conditioned air. If so I'd like to know.
0 -
Your unit is better than most. You are taking outside air and returning it back outside as opposed to the units chris i believe is referring to that only discharge air outside. There is only a discharge pipe on the rear of the unit. The air it is discharging to cool the condenser is conditioned air from the space.
0 -
two choices. A ductless mini split or a central system with your electric furnace.
0 -
some of the newer hotels have super quiet PTAC unit. I suppose those could be mounted on a shelf
Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream0 -
Every time I've tried to find a "two ducted" unit, it always ended up either you couldn't buy the parts to convert it, or, it simply wasn't what it seemed.
The OP's unit shows two ducts, but it looks like both just go to a common WYE connector?
@kadini Is that connector split inside, and going to two separate ports on the unit or are they two individual hoses? I couldn't really see in your picture, I just assumed it was like I've always found. The units seemed like they could do it, but the parts simply weren't available in the U.S. for whatever reason.
Single pipe 392sqft system with an EG-40 rated for 325sqft and it's silent and balanced at all times.
0 -
I thought OP was asking for basically a PTAC (PTHP for heat pump) or what someone might call a through-the-wall unit. They are available, I would rather just see a handy homeowner DIY a cheap-ish mini split though. Little bit more money, but a lot smaller hole in the wall, and typically way more efficient
1 -
Yeah,
I don't know if it's just me but I feel like window units / through the wall units have dropped in quality big time over the past 20 years. The late 90s still had some really good ones and then they all just got worse and worse. Even the pull out accordion sides used to work and fit really good, now they're terribe.
Single pipe 392sqft system with an EG-40 rated for 325sqft and it's silent and balanced at all times.
0 -
I concur that a 'mini-split' type system will make more sense than a 'through-the-wall' type system.
You have a much smaller hole through the wall, and you have flexibility about placement of both the indoor and outdoor unit.
There are multiple indoor unit options. The OP states that there isn't space inside the ceiling for the indoor unit, but there are versions that surface mount on the ceiling.
For heating, I'm a fan of 'console' type indoor units near the floor, but OP states that this doesn't fit the use of the space.
0 -
i remembered your question from last week and found this product yesterday when a Rep came in
and mentioned they where looking at the line
take a look at Olympia splendid Maestro system
they claim its a wall mounted heat pump with no outside unit
0 -
OK sorry I was on a trip. I found this on Ebay. I probably wouldn't buy it there.
Mitsubishi GX 18000 BTU 22.5 SEER2 Ductless Mini Split Heat Pump AC System R454BDidn't post the link because I wasn't sure about violating price guidelines (again).
It's the whole system.
Only thing else needed would be the external wall mount.
This very inexpensive mounting bracketry (from Amazon) looks like it would work. Says it has rubber isolator mounts.
I will pay somebody to install. 18,000 btu may be more than I need but rather have too much than too little. Have easy access to 220v connections from nearby house electrical panel. I like Mitsubishi but they tend to be pricey. I have been very happy with my Hisense portable heat pumps. I'm sure they have something similar to the above for less.
Am I missing anything? Suggestions for brands or anything else.
As always thanks for the help!
0 -
Have you looked at the cost of this unit? Olympia Splendid USA 12,000 HP. there is a video on their website that looks exactly like what you are asking for.
You might need to find another wall for the artwork
Edward Young Retired
After you make that expensive repair and you still have the same problem, What will you check next?
0 -
Yes I looked at it. Sorry I didn't respond before. The mini split takes up less space inside and the pass throughs have less impact on the wall. But you're right that is exactly what I was describing previously.
0 -
Mitsubishi
Fujitsu
Daikin
All have strict restrictions concerning warranty and online sales.
0 -
Lot of brands out there, most overseas ones are OEMed by either Midea or Gree. There are also version with quick connect fittings for the refrigerant which doesn't need an HVAC tech to connect like:
As for sizing, run through the math here using a recent winter fuel bill. That will tell you the heat loss for the whole house and can figure out what percentage of that you want to cover with the heat pump.
One word of caution about mounting. Although those brackets are called wall mount they should NEVER be used on framed walls as the vibration will transfer into the framing. You always want to mount to masonry or ground mount the unit. Make sure the unit is above the expected snow cover. The outdoor unit makes a fair bit of defrost water in the winter, so mount it away from walkways.
0 -
-
Seriously? I bought a small Sears window unit for an add on upstairs bedroom for a house in Texas. The central air wasn't getting it done. Not sized right I suspect. None the less that window unit worked great for 15 years with no servicing other than cleaning or changing filters. Still working when I sold the house in 2000.
0 -
I plan to buy through and have whatever I get installed via a local contractor.
0 -
Not being able to mount on a framed wall would be a show stopper. I have 3 heat pumps the 2 portable units for the bedrooms and a third to heat our 15' diameter above ground pool the 2 months a year we can use it. The vibration from the portable units is noticable but not unbearable. Other than sound possibly being an annoyance is vibration really an issue?
0 -
simple and basic.
a mini is much more complicated.
There’s a reason MrCool is 60-75% less them Mitsubishi0 -
You can mount it on a framed wall and secure it to the studs for a solid attachment. You just need to install proper vibration dampers so the vibration does not transfer to the structure. Most of these units don’t produce much vibration anyway. Every one I’ve installed has been very quiet—both the indoor unit and the outdoor unit.
here are 2 different types that will work:
Edward Young Retired
After you make that expensive repair and you still have the same problem, What will you check next?
1 -
the Fujitsu at our summer house certain harmonics would be noticeable late at night when everything was dead quiet.
those mounts solved that.0 -
I have asked for quotes from 3 contractors via Mitsubishi Web site.
0 -
check the contractors references
Great system but everything has to be done correctly
0 -
Yeah there's the rub isn't it.
0 -
@kadini If you ware Ok with a window shaker, a mini split will be WAY quieter. The difference between one mounted on stud walls and one mounted on foundation/ground is the first one you hear, the other one is silent.
The issue is depending on where on the walls the unit is mounted, it could resonate at certain compressor speeds (these are variable speed units, compressor speed changes with load). What usually happens is the unit is mostly Ok, but sometimes you hit a resonance where the house sings. If you are luckly, it will be quiet, if not, it will be annoying.
@EdTheHeaterMan I tried every kind of isolator to fix a stud mounted unit. They definitely helped but there is no comparison with ground mounting.
The challenge is most isolators don't have enough deflection and you need add a lot of weight (ie concrete pavers) to the wall mount brackets.
To work at the typical compressor speeds you need about 3/16" static deflection and about 150lb of weight. Most isolators are not soft enough for that and the ones that are won't hold any shear load. Most wall mount brackets won't hold all that extra weight either.
@pecmsg I have to maintain about a dozen minisplits from various manufacturers. Out of all of those over a decade I've had one control board failure on a place with noisy power. Rest of the issues were clogged drain lines. Over the same time, I've changed a lot of thermopiles, flame sensors and draft inducers on fuel burners. The usual issue I have seen is refrigerant leaks which are due to sloppy install.
1 -
I’m glad your getting lucky.
I avoid all the cheap knockoffs.
Mitsubishi, Fujitsu or Daikin are all we will service.
we don’t honor warranty unless sold by us.0 -
No chance you're in Seattle area?
0 -
the right cost!
Eastern Long Island 😇
0 -
One or two I would call lucky. A dozen means that they are pretty decent.
There are no cheap knockoffs. Most (all?) random branded units are made by either Midea or Gree (world #3 and #4 HVAC manufacturers). Midea/Gree have many different performance and feature sets and the off brand ones do tend to use the lower end product line. Usually the hyper heat ones (units rated down to -22F) are better quality.
Even the big guys go through tough patches of quality. Fujitsu had a batch of indoor heads that were pinholeing a while back.
0 -
Pin holing?
0
Categories
- All Categories
- 87.6K THE MAIN WALL
- 3.3K A-C, Heat Pumps & Refrigeration
- 59 Biomass
- 430 Carbon Monoxide Awareness
- 124 Chimneys & Flues
- 2.2K Domestic Hot Water
- 5.9K Gas Heating
- 120 Geothermal
- 169 Indoor-Air Quality
- 3.8K Oil Heating
- 78 Pipe Deterioration
- 1K Plumbing
- 6.6K Radiant Heating
- 396 Solar
- 16K Strictly Steam
- 3.5K Thermostats and Controls
- 56 Water Quality
- 51 Industry Classes
- 51 Job Opportunities
- 18 Recall Announcements

















