Home Forums Hunting & Shooting Hunter's Campfire Heat pumps and cold weather

Please note I live in NW Arkansas now and not Alaska.

My 20 year old AC unit is on it's last leg. I have a gas furnace inline with the AC coils in the attic that works great. I've had two different people out to give me quotes and they both say I will need to replace the furnace when I replace the AC as the new unit will not work with the old furnace. Not sure what to think of that, but one of the guys I trust, so maybe it's not compatible with new technology.

Anyway, looking at the cost of a new AC unit and furnace or lower cost of going with a heat pump only. I'm not concerned about electricity usage, but more concerned with a heat pump when it's below freezing. NW AR is not super cold, but we do have at least 30 nights of the winter below freezing and several daytime highs below freezing. Will a heat pump work at 20 degrees F? If highs never get above freezing for 3-5 days, will it just stop working?

Whatever I put in will be in the upper range of efficiency, if that even matters. At least 18 SEER2 and 8.5 HSPF2.

I've seen quite the push lately for people to switch to heat pumps, mostly I think from the electric company, and the claims they work fine in colder climates. I just don't know anyone who actually has one in a really cold area and don't want to drop $15K on something that's not going to work.

I do heat and a/c for a living. If you can PM me the model numbers for what the are quoting you where they’re saying it won’t work with your current gas furnace, I can tell you if they’re being truthful or not. A heat pump in theory will work until absolute zero. But, that does not mean it’s going to supply enough heat to keep up with your home’s demand when it’s below freezing. In order to figure out at which point the heat pump starts getting in over it’s head is called the balance point. In order to find a heat pump’s balance point for your home, a Manual J needs to be performed on your home which is a heat load calculation.

I'm at work tonight and can see what I have in the attic tomorrow. The outside AC unit is a 5 ton Trane XL19i installed in 2004, so I think the gas furnace would also be a Trane brand. Manual J calculation is 60K

My heat pump keeps the house at desired temperature in zero temps. It doesn’t get much colder than that here.

I have an air to air heat pump, installed 3 years ago. It works below 20 but it works hard doing it, and would wear out earlier, except for the propane backup, which comes on at 20 and shuts off at 25.

I just replaced our American Standard heat pump and went back to a central air unit. Already have a high efficiency gas furnace that kicked in at +10F, but we were never big fans of the heat pump when it got below freezing. I seriously doubt we recovered the upfront cost of the heat pump in energy savings, but I could be wrong.

A heat pump would be strained in Alaska .

I have one here in N d with electric furnace backup. Heat pump kicks out at about freezing or a little above that. This was installed and set up by the REC power company. I’m guessing they know what works. Edk

I've had 3 homes with heat pumps and hated them. They cooled just fine, but when the temps got down to about 40ish, the house never seemed to be warm. Latest one was installed in 2008 just when the 410 was coming out and I got one of them, hoping it would do better, but it didn't.

When I remodeled the house I'm in now, I already had NG, so I stuck with it and have never regretted it.

They claim they have improved the heat pumps a lot since I got my last one. Maybe they have.

It’s pretty simple……the lower the temperature below, around 40 degrees, the less efficient they are. Pretty much useless at freezing temps.

Plus, you are totally dependent upon the electrical grid! Get a gas or propane fired heater (decorative if you like) with a fan as an option and be free of the grid.

We’ve been heating 2500 sq./ft (two levels) quite nicely with a 30K btu freestanding propane heater for 4 winters now! The only time we had to use our little 10K propane heater upstairs was this year…..when we hit -38 F. We had many days with below zero lows. We have not used our forced air furnace in 4 years! By the way….we don’t have a blower on our heater. We do however have ceiling fans which help maintain a very even temperature throughout the house! memtb

Are you guys who are pop poking heat pumps talking about currently produced units or the ones from 30 years ago? Technology has improved them through the years.

You’ll most likely need electrical heating strips in the evaporator duct works.

How much of the 60k is sensible/latent? Is your current system communicating?

Heat pump with backup heat strips is all we have had for11 years and I’m not far from you.
Most of the time the strips never come on but it sure isn’t like a gas furnace or wood heat.
Ours is an 18 seer.

The Laws of Physics haven’t changed! When within their operating parameters they may be more efficient presently...but, still must operate within those parameters! memtb

We put 7.5 or 10KW heat strips in older air to air units that came on during reverse cycle when in colder high humidity or foggy conditions. But that was years back and I am out of the business now. Many heat pump improvements in the last few years.
Some home owners never knew their HP had heat strips.

Do not do a heat pump anytime it’s below 40 heat strips kicks on and electric skyrockets. I live in southeast Arkansas and own one and when it’s time to replace I will go with natural gas heat exchanger!

Our house is four years old. 2000 sq ft mobile home. My son is is in HVAC. He purchased and installed our heat pump right after the home was in place and setup. Wholesale prices makes more difference than you could imagine.

We commonly see winter time temps around ten to twenty degrees. Sometimes it will not break freezing point for many weeks at a time. Sometimes it goes subzero.

We had some sustained cold this winter with daytime highs around twenty for several weeks. I remember it well as I was outside all day during that time.


It does get moderately cold here, but it makes up for it in July and August with 100 Plus for extended times.

Our winter heat bills pretty well match our Summer AC bills. I do not know that the electric furnace back up has ever kicked in. I pay $200/mo to the power company. Sometimes I get considerably ahead (Apr,May, June, Oct, Nov) then the surplus will trend lower in months of high usage.

One problem with a heat pump in cold weather, even in our arid climate. As the unit pulls heat out of already frigid air, frost will collect on the evaporator. Periodically the reversing valves switch it back to AC mode for enough time to clear that frost, as in a frost free refrigerator. When that happens, the accumulated water drips onto the base under the unit, where it freezes and accumulates. Sometimes in excessive amounts in sustained cold weather.

I turn on a garden hose occasionally and use it to melt the ice away, so that it runs off of the patio. Even if the condensate is not accumulating as ice, there will be a constant wet spot under the unit if it is on concrete, as long as it is in heat mode.

When the temps approach zero, our unit produces warm air. Still warm enough to keep the house above our thermostat setting of 66 degrees. But it has to run almost continuously to do so. And there is no source of HOT air to stand over and warm quickly when you come in from outside.

New heat pumps are incredibly efficient. Ours works very well. But I miss the single point heat source of a fireplace, wood stove, or even a pellet stove.

We had a heat pump in our old house because gas wasn't available. When we picked a place to build gas available was a must. We have a heat pump and a high efficiency gas furnace. We chose that when we built because down to 40º the heat pump was more economical. That changed and now I set the heat on emergency heat (gas) all Winter. We have a backup generator, and you only need 120VAC to run the furnace.

All the shrubs around my house are dead from the cold last winter. It never for a second got below 72 degrees f in our home. I love a heat pump!