Heat pump on the ground to heat/cool third floor, dumb idea?

Question

Hello,

I have a 3rd story occupied unit that needs a heat pump replaced. Current heat pump unbeknownst to me is leaning against a chimney and supported by 2x4s and on a peaked roof. HVAC contractor went to replace today with a lift and realized the roof was not flat and does not feel safe or comfortable removing old heat pump and installing new heat pump on the roof. He mentioned installing heat pump on the ground. Has anybody done this before?

The 3rd floor (loft-like area) does not have a gas line or adequate space for furnace. Electric baseboard heat is an option that I would like to avoid because I'm in Ohio and worried resident's electric bill will be sky high d/t cold winters and poorly insulated attic/3rd floor unit. Current residents have complained about high electric bill d/t window air conditioners to cool unit during summer d/t broken heat pump.

What would you do?

Chris Gerstner · Answer

Hello Tyler,

I'm almost brand spanking new to REI but am the third generation of my family to be in the HVAC business in the Dallas area.

Here, we have many heat pump units on the ground floor for third story units. Many builders are still building them that way right now actually.

Typically, you find the condenser on the ground connected to an air handler in the attic above the third floor which supply's heat or cooling to the unit.

Your contractor should know what to look for but we all know what happens sometimes when you just trust your contractor. You'll want to specifically ensure that the exact condensing unit he is going to use will not have an issue with the length of the copper lineset and the rise (height that it will have to pump the freon up). Most manufacturers will work well for that application but there are standards for each model which usually can be found online that will show what the exact recommendations and limitations are. Look up the product data sheet or PDF for the exact model he is going to use.

Now, you say that there isn't room for a furnace in the third floor area? Was there not an air handler already there somewhere?

Could you have a roofer build a good platform for it to sit on, on the roof? The cost difference would be about the same whether you build the roof up the right way or relocate it to the ground level here in Dallas.

I would typically recommend finding a place on the ground to install as it will be easier to maintain and service but I don't know the rest of the details of your particular place. Plus, I'm in Dallas and not sure if there is any other weather related reason to not put it on ground level.

Landrin Lewien · Answer

@Tyler Speelman

Hello Tyler, I do industrial HVAC, I’m a service man and I went to school for HVAC. I would definitely recommend a heat pump for the 3rd floor but you have a few options. The condensing unit is fine on the ground and I agree that it’s a much safer location for servicing. Your contractor will run a line set up along the outside of the building to the 3rd floor. And depending on what you want it will run into a small air handler with a coil and fan, or if you choose a “mini split” there will be multiple line sets running to the “heads” basically the fan and coil all in one that mounts inside the room and looks very nice.

Depending on the square footage and what the original heat pump was (air handler with duct work already installed?) decides what unit to go with.

Mitsubishi mini splits are always nice or a Trane. Also with the supplemental heat I doubt it’s needed, heat pumps are 300% efficient and can provide substantial heat at very low outside air temps, + there on the 3rd floor and what does heat do? Rise from the other floors.

Thanks

Chris Gerstner · Answer

I'm glad I could help, Tyler. Nice to finally contribute to a forum that has taught me so much!

Best of luck and let me know if any other questions come up.

-Chris

Brandon Sturgill · Answer

@Tyler Speelman No worries...@Landrin Lewien is the expert here...to his point, the tech is good...these things are efficient for sure....even mini-split tech is crazy good right now....

Sounds like you have some logistical issues blended in here...I'd seek a couple of quotes...just be clear with your needs to get the best solution.

Good luck!

Bart H. · Answer

Heat pumps will be your most efficient heating/cooling source.  However, there is a  theoretical limit based on the thermodynamic cycle  as to how much they can heat a house when the outside temperature drops. That's why in northern climates they are rarely used unless there is baseboard heating or geothermal heat pumps.

If you have gas at the house, I would see if you have enough gas supply to put a gas furnace in, and either go with a traditional AC unit or else put a new heat pump in and supplement it with bas or baseboard heater.

John Teachout · Answer

Seems like OH is a little far north for a heat pump. They work well here in GA but in cold weather when the heat strips kick on they suck the power. I'd go with straight AC and a gas furnace. Doesn't seem all that difficult to run a gas pipe up to the third floor.

Brandon Sturgill · Answer

@Tyler Speelman you said no gas line to the 3rd floor?...but to the rest of the property? A heat pump is used as an alternative to gas, so your concern about electric base-board heat is invalid...the entire heating system would be electric...

Heat pump technology has come a long way and these things are good at providing heat to a property with a 3rd floor as long as your ducting is good...and more importantly, your R-value...I would look at 1)- better insulation, 2) extending the gas line and adding a gas furnace, 3) installing a PTAC unit, 4) Installing a mini split...or baseboard heat...its actually a really good heating source...and think more about hydronics...in my opinion hydronics is absolutely the way to go in almost any situation with boiler technology...

Best of luck.

Tyler Speelman · Answer

@Brandon Sturgill

Yes, gas furnaces for all other units except for 3rd unit.

All great points. My understanding was that a heat pump with back up heat strips would be best option as opposed to baseboard heat + window Ac unit because heat pump would heat and cool more efficiently.

I appreciate your recommendations and tips. I will consider adding insulation and will have to look up R-value.

Heat pump on the ground to heat/cool third floor, dumb idea?

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