Worthless Electric Heatpumps

[Turin39789]

Moved into a renovated circa 1900 home this summer. Insulation was added, but obviously still some gaps. Enjoyed a full day at 0 degrees and first floor can only muster 58 degrees.

House is heated by a split system with two heat pumps. Don't know why he didn't run gas when the place was down to the studs.

Have a 37k btu gas fireplace on the way. Is it at all reasonable to swap out the units and go with gas furnaces and separate air units, or just a money sink? Electric water too. Doesn't usually hit this cold in KY, but just not loving the electric heat idea.

 

[herm0016]

by split systems, do you mean inverters? the ones you mount on the wall? which close to, but not exactly like a traditional heat pump.

sounds like you need more capacity. the inverter systems are great for small spaces, but i would not want to rely on them for your main heat source. A traditional heat pump would be a fine primary heat source.

 

[BoomerD]

Heat pumps are OK until it gets FUCKING cold...then they're worthless and your normal heating system should kick in.

You say the house is old and it's had some extra insulation added...what about the windows? Single pane windows are horrible.

 

[spidey07]

Heat pumps are worthless if it gets cold. Natural gas all the way.

-edit-
Dude, you're in KY. Go gas for everything. We have super cheap electricity, but even better super cheap NG. In the long run NG will be much cheaper and more comfortable. Temps like these do happen in our state, it's not that unusual to dip into single digits.

6400 sqft house, LG&E bill is never more than 270 in the deadest of winter.

 

[Turin39789]

by split systems, do you mean inverters? the ones you mount on the wall? which close to, but not exactly like a traditional heat pump.

sounds like you need more capacity. the inverter systems are great for small spaces, but i would not want to rely on them for your main heat source. A traditional heat pump would be a fine primary heat source.

Nah, just one unit for first floor, separate pump for 2 and 3.

 

[Ferzerp]

Is your auxiliary heat not working right? Heat pumps can only achieve a certain temperature delta, and when it gets as cold as it is outside right now they have to supplement it with resistive heating. Mine has been using aux quite a bit today, but it's maintained temperature in the sub-10 degree weather just fine.

 

[Turin39789]

Heat pumps are OK until it gets FUCKING cold...then they're worthless and your normal heating system should kick in.

You say the house is old and it's had some extra insulation added...what about the windows? Single pane windows are horrible.

Windows arent perfect but were replaced around 20 years ago, except for a big stained glass oval on 1 and a few diamond and porthole windows on 2-3.

 

[bradley]

Modern day heat pumps need to place themselves into defrost cycles under freezing, pretty much rendering them worthless. One minute they are blowing 70F warm air, suddenly to experience a 20-30 degree drop for an hour's defrost.

 

[boomerang]

Replaced furnace and AC about 8 or so years ago and went with a Heat Pump in place of a standard condenser unit because the .gov was kicking in some cash. Bottom line was I was able to get a higher efficiency unit for free.

At installation I was told to set the balance point at 30 degrees. My auxiliary heat source is the NG furnace. I now have the balance point set at 45 degrees and 50 would probably be better. NG is now cheap and electricity is getting more and more expensive. It does not make sense to make the Heat Pump work its ass off trying to extract heat from air below 45 degrees. The bonus is that it never goes into a defrost cycle.

 

[Markbnj]

Windows arent perfect but were replaced around 20 years ago, except for a big stained glass oval on 1 and a few diamond and porthole windows on 2-3.

I bet that big stained glass window is leaking an asston of heat, though. Especially if it is real, with leaded glass panes.

Like the others, I have usually heard of heat pumps being paired with auxiliary systems for when it gets very cold. In any case, you've discovered one of the downsides of old homes, however renovated they might be. Get used to living a little more like your ancestors... who were cold in the winter .

 

[Turin39789]

Heat pumps are worthless if it gets cold. Natural gas all the way.

-edit-
Dude, you're in KY. Go gas for everything. We have super cheap electricity, but even better super cheap NG. In the long run NG will be much cheaper and more comfortable. Temps like these do happen in our state, it's not that unusual to dip into single digits.

6400 sqft house, LG&E bill is never more than 270 in the deadest of winter.

Yea, going to get some quotes. Assumung it will be to add a furnace and leave the pumps. Not sure if they have a resale value. Like I said, have a gas fireplace onthe wway, was suposed to be here 3 days ago but the store didn't order it. Tempted to.have a thermal imaging done off the home but LGE offers a free one after you are in the home for a year.

Just a little pissed that we didn't get the fixer upper I wanted and I'm going to wind up doing lots of things to an otherwise well done home. But really didn't have time to do a reno between work and kids.

 

[Ferzerp]

Assumung it will be to add a furnace and leave the pumps

It better be unless you think you're going to cool your house by burning gas.........

 

[bradley]

I recently visited a nursing home that had a newly installed Mitsubishi heat pump, beautiful looking system. Too bad elderly men/women mute for years suddenly felt the need to complain about the frigid indoor temperatures. Like old people aren’t cold enough already.

Obviously whoever designed/installed the system should lose their HVAC license.

 

[fstime]

By split system, I hope you do not mean two ductless mini-splits and instead a traditional heatpump/condenser with an air handler and duct-work throughout the house.

If that is the case, furnaces are much cheaper than boilers with 95%+ efficient units only costing slightly more than basic 80% units.

Do all the ducts connect together, or do you have a split system where half are on in the attic and the other half are in the basement separate from each other?

If everything is interconnected, one furnace is probably going to run 800-1300 depending on the size, add another ~$200 for an AC coil. Labor can be a little brutal. Hopefully getting the gas from the meter to your furnace is not too difficult. Probably expect to spend a few thousand.

A lot of NG companies will run the line from the street to where the meter will be setup outside for free or at minimal cost, especially if you also elect to do hot water.

 

[ControlD]

Modern day heat pumps need to place themselves into defrost cycles under freezing, pretty much rendering them worthless. One minute they are blowing 70F warm air, suddenly to experience a 20-30 degree drop for an hour's defrost.

If your heat pump requires a one hour defrost cycle it isn't that modern. My heat pump (installed in the last 15 years) has about a five minute defrost cycle at which time the aux heat kicks in. There is no drop in temperature during the cycle.

 

[spidey07]

In ky my state ng is the only way to fly.

 

[Turin39789]

Bah. 2nd floor down to 63. Space heater deployed to babies room.

 

[PowerEngineer]

Your situation sound a bit like the one I was in many years ago. It was our second year in our house when we experienced unusually cold weather; the inside temperature couldn't be held above 60 degrees even though the gas furnace was running all the time.

I found out afterward that the building codes in the area had been changed to encourage the installation of smaller furnaces that were somehow supposed to be more efficient (longer on-cycles?). My 80% efficient 80,000 BTU unit was only delivering 64,000 BTU to the house, which was supposedly fine for a 20 degree ambient. It fell far short when the temperatures fell into the single digits and the winds were blowing 30+ mph! A 96% efficient 100,000 BTU furnace fixed the problem.

It's possible that (like our furnace) your heat pumps were similarly undersized for this artic vortex.

As others have suggested, there should be heating strips in the plenums of the heat exchangers that come on to add heat when the heat pumps can't extract enough from the cold ambient air. You might check to see if these heating strips are turned on. Is it possible that there's a setting on the thermostat that turns them on?

Heat pumps are essentially the same as air conditioning units except that they can move heat in either direction. If the heat pumps are providing you with adequate cooling in the summers then I wouldn't replace them. You could add a gas furnace as an alternate source of heat below a cut-off ambient temperature (maybe on just one of the two systems). We have a heat pump/gas furnace set-up like this that works well for us.

Good luck!

 

[BoomerD]

Heat pumps are far from worthless, but they have to be done correctly. Right size for the space, paired to the right heating unit, etc...PLUS, the house insulation has to be good, windows should be double pane, preferably double pane with inert gas in between the panes...and they should still have their seal. Many cheap double pane windows lose their seal in just a few years...then they're almost as worthless as single pane windows.

Talk to a heating and cooling contractor. Also, your electrical utility MIGHT offer a free home energy audit which might help you pinpoint the source of the problem. (Could be a faulty heat pump, poor insulation, leaky windows, etc.)

 

[Turin39789]

Upstairs unit had the wrong thermostat on it, so the electric auxilliary heat wasn't wired up.

Downstairs unit looks like it needs a refrigerant charge, but too cold to to that, so has to wait till the weekend. Also the auxilliary electric downstairs has one bank of coils installed, to the three upstairs. Tech thought the installers either put the units in backwards(heavier heater upstairs and lighter down) or that the one downstairs was just the wrong unit. Have to wait on that to get it sorted out and go back to the builder.

 

[NoTine42]

Heat pumps are awesome..with a natural gas backup.
After I had a heat pump installed in my previous, 1920's home, I left it in E Heat (all gas) then got a $400 utility bill. So I set it back to hybrid Heat and only had a $200 bill the next month, while other co-workers still had $400 bills.

Natural gas-only is more comfy (if you like a blast of heat) but the savings with a heat pump are fairly impressive.

 

[iGas]

Every heat pump have different HSPF to EER rating that must size correctly for heating and cooling to get the most out of it. And, don't you mean ductless split system?