As someone who switched to a heat pump recently, you should know "your mileage may vary." Don't confuse physical efficiency for cost efficiency. In many places, natural gas is still more cost efficient, even if it isn't as efficient in terms of physics.
Heat Pumps Take on Cold Climates
11–20 of 83 posts
Re: Heat Pumps Take on Cold Climates
#12We decided to install a cold climate central ducted heat pump system, operating down to -20 F and swapped from wood to pellet stoves in our fireplaces. We didn't have AC previously, and got too old to haul wood around. We can run the heat pump on the coldest days but burning biomass is cheaper and has a nice ambiance. Does wonders for humidity in the summer time too!
Re: Heat Pumps Take on Cold Climates
#13> But heat pump manufacturers say they now have the technology to heat homes just as efficiently in bitter cold as they do in milder winter temperatures. This claim defies thermodynamics (and I expect better from IEEE). Heat pumps are bound to be less efficient as the spread between inside and outside temperature grows. (They might be just as effective or they might be just as efficient as current heat pump tech , bu…
" just as efficiently " as what?
The way I read it was "just as efficiently as a conventional furnace". IOW, a COP of 1 at bitter cold temperatures.
Re: Heat Pumps Take on Cold Climates
#14> But heat pump manufacturers say they now have the technology to heat homes just as efficiently in bitter cold as they do in milder winter temperatures. This claim defies thermodynamics (and I expect better from IEEE). Heat pumps are bound to be less efficient as the spread between inside and outside temperature grows. (They might be just as effective or they might be just as efficient as current heat pump tech , bu…
I've found that marketing material takes significant liberties with their claims, with the understanding that the audience isn't actually interested in the gory details, just the general question of "should I buy option A or option B?" I've been asked to critique statements that were flat-out wrong, only to be told yeah, thanks, nobody cares about that.
Re: Heat Pumps Take on Cold Climates
#15[flagged]
This would be nice. It's not the end of the world to convert them myself but given the large readership base that uses Freedom I'd like to see these with both. It's much easier for them to add our units than it is for us to adopt metric here anytime soon.
Re: Heat Pumps Take on Cold Climates
#16Is there a way to get your house (currently with hydronic gas heat) retrofitted for heat pumps that doesn’t result in either a ton of demo or ugly lines all over the exterior? I tried to switch over last year only to find the savings were not that great in my climate, and that it would have an unacceptable aesthetic cost.
I had heat pumps installed in my house last year, to replace oil-based heat from baseboards. We have no drainage lines on the the front of the house, and only one bundle on the back. It follows the roof line, and then down a corner of the side of the house. So, yes, you will need drainage lines, but no, they shouldn't have to be all of the exterior. They should be able to be placed in an acceptable way. (Similar to, say, gutters.)
On the savings side: I think we're about even compared to oil. But I'm okay with that: we didn't have any air conditioning at all in the house, so we had no duct work. (We bought the house at the end of 2022 like this.) Since we were already doing significant work to install the duct work and get a new air conditioning system, I wanted to make them heat pumps to get off of oil. I think in the long run, we'll save money. I eventually plan on installing solar panels. And even if it's a wash in terms of money, I'm care about climate change, and I want to do what I can to electrify my house.
edit: After looking at other comments, I should clarify what we have. We have two condensers outside, and three air handlers inside. It acts like "central air", for the most part. We do have one mini-split, for the main bedroom, as we could not get ducts to it. My point here is that "heat pumps" do not necessarily mean "mini splits." My house is almost entirely centrally heated and cooled through duct work.
Re: Heat Pumps Take on Cold Climates
#17> But heat pump manufacturers say they now have the technology to heat homes just as efficiently in bitter cold as they do in milder winter temperatures. This claim defies thermodynamics (and I expect better from IEEE). Heat pumps are bound to be less efficient as the spread between inside and outside temperature grows. (They might be just as effective or they might be just as efficient as current heat pump tech , bu…
" just as efficiently " as what? The way I read it was "just as efficiently as a conventional furnace". IOW, a COP of 1 at bitter cold temperatures.
the next words are "[as] they do", so I naturally read it as 'those same heat pumps'.
Re: Heat Pumps Take on Cold Climates
#18> But heat pump manufacturers say they now have the technology to heat homes just as efficiently in bitter cold as they do in milder winter temperatures. This claim defies thermodynamics (and I expect better from IEEE). Heat pumps are bound to be less efficient as the spread between inside and outside temperature grows. (They might be just as effective or they might be just as efficient as current heat pump tech , bu…
If you want to get nitpicky: Cycle losses aren't the only source of inefficiency and in fact the end-to-end efficiency curves of most domestic heat pumps tend to be pretty flat through their useful range. Basic thermodynamics, provided a refrigerant that is well matched to the cycle (which is what the article is actually about), isn't really the core design point.
Re: Heat Pumps Take on Cold Climates
#19> But heat pump manufacturers say they now have the technology to heat homes just as efficiently in bitter cold as they do in milder winter temperatures. This claim defies thermodynamics (and I expect better from IEEE). Heat pumps are bound to be less efficient as the spread between inside and outside temperature grows. (They might be just as effective or they might be just as efficient as current heat pump tech , bu…
My father has a heat pump that works fine in alpine climate (half of the winter snow outside) for more than a decade now. Not sure about the precise english terminology here, but his hear pump works using the deep ground water next to our house. The temperature of that water slightly dips in winter, but it is no more than a degree.
It is a very old house that before had a oil heating system and I think the replacement worked quite well.
Re: Heat Pumps Take on Cold Climates
#20Earlier quoted context omitted.
Mine has one pipe going into the basement, and the mains power connection. What sorts of ugly lines are you referring to?
I think probably the ugly lineset covers characteristic of lowest possible budget (and therefore overwhelmingly most common) installation of air-to-air heat pumps.
I guess this depends on where you locate the heat pump. On mine, the insulated pipe and mains connection are within two feet of the building.