Heat Pumps...PRO & CONS??

Question

Can anyone give me information and/or experience with heat pumps. From what I understand they are more efficient in warmer climates and provide a cleaner air. Any feedback is appreciated! Thanks

Charlie MacPherson · Answer

I don't know of any negatives.  My neighbor installs them and I went over a proposal for our new home here in Plymouth MA.

We currently have baseboard electric heat - the highest cost per BTU of any heat source.  He tells me that a single baseboard heating element can eat 3KW of power.  We have about 10 in our home.

He thinks we can replace the baseboard electric with a split unit - a single heat pump with the "through the wall" units that will provide heat and also whole house AC.  He said that the unit eats 450W - that's 0.45KW, vs 30KW if all the heating elements are calling for heat at the same time.

We will move forward with that project as soon as we have a fewer high priority projects done.

PS - here in MA, there are rebates to help with the expense.

Dustin Beam · Answer

This is partially true. I'm a Mech Engineer (do HVAC/Plumbing design). There are some limitations to heat pumps, and the colder it gets, the less effective they become. They pull heat from the outside and put it in your house. When the AC is running in the summer, it pulls heat from your house and puts it outside (your AC also becomes less effective as it gets hotter).

It can still pull heat from the outside below 40 dF, however you start to risk freezing on your outside unit, which would make it ineffective. There are solutions to that though, you can run the unit in "reverse" (normal coolign mode) and it will thaw the unit out. You can also put electric heat as backup in the furnace, so if the outside unit freezes, you used electric heat.

In any case, just speak to a local HVAC guy and ask them about the unit freezing and what kind of options they have.

Maurice D. · Answer

Nothing wrong with a heat pump in NC.  make sure the design is right (the right tonnage for the home).

I'd play with Geothermal, if I were doing new construction or a large rehab on multi-family.

a typical 1.5Ton unit will have a 3-4.5KW emergency strip for those days when the temp is well below 32F

Kurt Dieringer · Answer

I recently installed geothermal heat pumps on my duplex. It was an experiment in profitability, and the verdict is still out. Headaches are the major downfall besides more upfront cost (definitely hire a pro). You can't beat the efficiency, so it depends if tenants will pay extra for it. On my own house, it's the only thing I want.

JD Martin · Answer

You're down here near me where electricity is (relatively) cheap compared to a lot of the country. And the climate is mild, so heat pumps are pretty common. I would do one before I'd leave baseboard heating in place, because if it's not too cold they're really efficient. Also, if you're using a heat pump, you only change the temperature a little bit at a time so that you don't initiate the electric coils, which use a ton of electricity (just like baseboard).

For rentals, if gas is available, I prefer to have a gas furnace and separate AC system. For starters, it's easier on your equipment, because you're then only using the compressor half the year. Gas is a more comfortable heat than heat pump. If the furnace goes out on May 1, you're not in dire straights like with a single-system heat pump, because you'll only be using the compressor and fan for the summer. And gas furnaces last a very long time. The furnace & AC compressor in my own house are both 25 years old and still chugging along nicely.

Juris Cooper · Answer

Hey, all! To help back up some or all of what you mention @Charlie MacPherson, below is a great, relevant article on the newer cold-rated electric heat pumps that can now rival the cost of natural gas: https://masslandlords.net/heat-pumps-now-cheaper-p...

I also like how it expands into the possibilities of tying into solar and the supplemental revenue/cost saving opportunities this can provide. Well, at least here in MA.

Hope this adds some value. Cheers

Matthew Graves · Answer

very informative Dustin! Much appreciated.

Dustin Beam · Answer

"Efficient" can often be misleading to the general public. For instance, electric resistance heat is almost 100% efficient. But it is generally more expensive than gas simply because gas is cheaper even though it does have more losses. Check your local gas prices obviously.

Heat pumps will generally put out MORE heat than it consumes, unlike electric resistance that puts out an equal amount to what it consumes (some fan losses, but mostly). How much it puts out depends on teh unit and what temperature it is outside. The answer isn't simple. In general, gas will be cheaper overall between the cost of the unit and cost to heat. But again, there are variables that you can't answer simply.

Max T. · Answer

How does the whole house electric heat pump system compare to a natural gas system in a northern city like Philadelphia?

Heat Pumps...PRO & CONS??

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