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cjm13905

Question on Heat Pump and Electricity Usage

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I own two homes. One in New York, that has gas forced hot air for heating. No A/C.

My second home is on Lake Gaston, in South most VA. It is a new home, built in 2007. 2000 sq ft, with two heat pumps, which I am not too familiar with how they work. One unit for upstairs, one for downstairs. I will need to do research on heat pumps. When we are not in VA, we set the AC to 85 and the heat to 55, and the only electric running is the fridge, a few led clocks (oven, microwave) and a dehumidifier in the basement.

The kWh usage for VA home for Jan - Feb was 1071, while our full time residence here in NY was 578 kWh. Our NY home we are using TV, computers galore, and lights. I am trying to understand why the VA kWh is so high, and almost twice as high as our NY home.

I know in VA, if we set the thermostat more than 2 degrees above the current temp, then an electric auxiliary system kicks in, and that is expensive to run, but when we aren't there that should not be running. In cold weather does a heat pump use a lot of electricity ? I thought the only electricity it would use would be for the blower. 

 

Thanks

 

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In really basic terms, a heat pump creates heat using the same principles as AC, but running in reverse.  That works pretty well, when its cool outside, but not so great when it gets cold.  It becomes less and less efficient the colder it gets outside, and therefore cycles for longer periods of time.  When the heat pump can no longer meet the demand called for by the thermostat, the auxiliary heat kicks is which is resistance heat (think giant toaster).  

So yes, a heat pump is very expensive to run when its really cold out i.e. single digits F.  If you haven't had a tune up on your systems recently, that could help some.  The refrigerant charge, and a few other things, can really affect their performance. I'd be looking at geothermal when the time comes, as that would give you pretty sizeable savings without having to run a gas line to the house, or using expensive propane.

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I think the south home has both pumps running at the same time occasionally. could be inaccurate thermostats. Or the sensitivity control is too wide. Overshoots the shut off temperature a lot.

Check how the rates are calculated in the winter.  Windows or a attic door open. basement windows open. Some systems have TOO MUCH outside air allowed to be brought in. Lots to check out.

Not enough insulation in attick ?

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17 hours ago, TNBrett said:

In really basic terms, a heat pump creates heat using the same principles as AC, but running in reverse.  That works pretty well, when its cool outside, but not so great when it gets cold.  It becomes less and less efficient the colder it gets outside, and therefore cycles for longer periods of time.  When the heat pump can no longer meet the demand called for by the thermostat, the auxiliary heat kicks is which is resistance heat (think giant toaster).  

So yes, a heat pump is very expensive to run when its really cold out i.e. single digits F.  If you haven't had a tune up on your systems recently, that could help some.  The refrigerant charge, and a few other things, can really affect their performance. I'd be looking at geothermal when the time comes, as that would give you pretty sizeable savings without having to run a gas line to the house, or using expensive propane.

Thank you very much.

The average temp for this time frame was over 8 degrees lower than last year, so the "really cold" issue is probably the answer, but it's probably time for a check up.

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The fact that the NY home has gas heat and the VA one electric (even with a heat pump) is a big reason why the difference in the overall electric bill alone.  While not a perfect apples to apples comparison, comparing the sum of your electric and gas bills on the NY home to the same in the VA home will give you a quickie look at how much it is or is not out of whack.

 

 

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Been very cold in Va in Jan - Feb - that's the main problem.  I set the heat pump thermo at 50 and turn the water off when not home.   No where near as efficient as gas furnace in these conditions.  

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10 hours ago, cjm13905 said:

Thank you very much.

The average temp for this time frame was over 8 degrees lower than last year, so the "really cold" issue is probably the answer, but it's probably time for a check up.

I feel your pain.  I have a heat pump as well.  January was colder for us this year compared to last.  My Jan '18 electric usage was 73% higher than Jan '17.  I knew it had been cold, but opening the bill surprised me a bit. 

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using electricity to make heat is very $$$$$$$.  Luckily your home with the heat pump is further south and doesn't have the expensive electricity costs that NY does.  My utility bill for january was pretty high , this year

 

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My N J total electric house with lots of glass is 3, 000 KW Hours in Jan - Feb  about 68 F daytime  Our 1500 s f ranch. 2 retired people.

The furnace is 4.... 5.5 K W heating elements. Glows like a huge toaster grid.   7 days on the big 17.5 K W generator was $ 850 of gasoline

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Sorry, just got back here. 

Both are around 2000 sq.

Pretty sure it was just super cold, and the heat pump isn't efficient in the cold.

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I always find it interesting that the New York Power Authority charges so much for electricity but always has the money to hand out to the politicians for there special public projects.

Gee, i wonder where they get all that money from. 

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The N Y bridge authority collects millions of needless extra tolls on bridges to Canada.  I pay for loads of mansion restorations.

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My wife works for a heat pump company here in Maine.  The big kicker is not to leave it "Auto" mode, if you are worried about freezing then just leave it in heat mode.  The heat pumps if left in auto mode will cycle all day long, thus driving your usage way up.  Side note, what systems do you have?

 

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