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Harnessing America's heat pump moment

heatpumped.org

31–40 of 571 posts

Re: Harnessing America's heat pump moment

#31
post #2

[flagged]

This is outdatated nonsense, I had my system installed 10 years ago and it works down to -15F... even the cheap $1k systems on Amazon work below freezing now Like any piece of equipment, just check the specs before you buy...

What’s the COP at -15F? It’s probably close to 1, which means you’re paying for resistive heat which happens to be the most expensive possible way to heat something up.

Re: Harnessing America's heat pump moment

#32
post #2

[flagged]

That is true only for air heat source. And even those work in below freezing (the one I have works down to -20degC) but as you say... with diminishing returns. Still, checking the technical spec, it says that at -15 degC it heats up a tad under 3x as much energy it uses. Pretty good I would say!

Re: Harnessing America's heat pump moment

#33
People are reluctant to install them because they don't work as well as the good old boilers we'd be replacing. I'm not saying they can't, and I'm not saying that there are zero models out there that work. But in practice, a lot of us that have interacted with heat pumps have the specific experience that they get anemic as the temperature goes down and eventually become unable to do much of anything.

I live in the mid-Atlantic (US) climate zone, where it's certainly not as cold as the north but definitely goes well below freezing regularly for several months of the year. The place I've lived for 15 years had a heat pump and a (oil) boiler with radiators, and when it was below 40°F (~5°C) I had to switch to the radiators. It's because it's old, everybody told me, modern heat pumps are better! So last year when both systems needed repairs at the same time, I not-entirely-willingly switched to a brand-new 2024-model heat pump. It absolutely could not keep up when the temperature was freezing until they came back and installed resistive heat strips for low temperature---these seem to be a fancy version of the heating elements in a space heater or a toaster. They do not seem to be particularly efficient. And to the extent that my "heat pump system" does now more or less keep the house adequately warm, if not as comfortable as the radiators always could, it's not solely due to the heat pump, but the other stuff they had to put in because the heat pump couldn't keep up.

My experience is far from unique. Maybe it's that they only install the good ones in farther-north locations! Maybe it's that the good ones are just way more expensive! I'm perfectly prepared to believe the factual statements about the physics and the tech. But if we're talking about perception and "why aren't more people looking to install heat pumps", it's because lots of people have experiences like the above, and that is what the industry needs to work on.

Re: Harnessing America's heat pump moment

#34
I live in a heat pump only house and the only thing I don't really love are mid summer electric bills, but I think that'd basically be the same with a dedicated AC. In my climate heat is more nice than complete necessity and usually only spikes bills if there are true hard freezes.

I will say, they seem to have gotten more expensive. It took about $10k to replace ours (it was over 20 years old and replacing coolant+fixing was quoted at nearly half that). Even though research suggested it could be more like a $6.5 to $7.5k cost, it was hard to even get people quoting in a timely manner, let alone getting any kind of a deal.

Re: Harnessing America's heat pump moment

#35

One other challenge is for existing homes a water heater may only have a gas line running to it. Want a heat pump hot water heater? Hiring the electrician alone, not to mention potentially ripping up walls will ruin any economic advantage.

This was a major barrier for me. I had to replace an existing natural, tanked gas water heater. Ultimately I just bought a $750 replacement because I could easily swap it out myself. Installing a heat pump would have involved an electrician to install a new circuit, and possibly other changes. While there were some 120v models available locally, they all had pretty bad reviews. So I would have paid a couple thousand dollars more. Maybe I could break even over 10 years paying less for gas but that seemed like a poor use of funds.

Re: Harnessing America's heat pump moment

#36
Cool to see a Heat Pump article near the top of HN! I'm the founder/CEO of Quilt (https://www.quilt.com/), which is mentioned in the article, and a decade+ daily reader of this fine site. At Quilt we've run the Nest playbook for ductless heat pumps as our first product. The plan is to do what Tesla did for automotive to the built environment infrastructure category (HVAC, plumbing, etc) and create the first major American manufacturer in a ~century.

The article has bullet #1 in problems to solve as "Contractors who default to what they know." This was one of my founding hypotheses to and it turns out I was wrong, this was the hardest won learning yet at Quilt. We originally were fully vertically integrated and had our own installation force because of this reason – we wanted to solve all the big problems, thought contractors were one of them, and so had to become a contractor. But we quickly saw we were getting in the way of our own mission to accelerate the energy transition (because we had far far more demand than we could scale operations to reach it). So in March we (initially cautiously) switched partnering with existing contractors and I have been delighted by the industry reception. There are so so many existing contractors who want modern tech and see working with us as a breath of fresh air. I definitely sold them short and in retrospect it was naive and even a little elitist.

Happy to answer anything more. Also I'd be remiss if I didn't mention that we're growing super fast and just posted an Embedded Software Engineer role: https://job-boards.greenhouse.io/quilt/jobs/4952684007 :)

Re: Harnessing America's heat pump moment

#37

Earlier quoted context omitted.

This is outdatated nonsense, I had my system installed 10 years ago and it works down to -15F... even the cheap $1k systems on Amazon work below freezing now Like any piece of equipment, just check the specs before you buy...

What’s the COP at -15F? It’s probably close to 1, which means you’re paying for resistive heat which happens to be the most expensive possible way to heat something up.

Just checked the spec of mine at -10degC. It's a bit over 3.

Re: Harnessing America's heat pump moment

#38
post #23

Earlier quoted context omitted.

Cold climate heat pumps have improved a lot, even in the last 10 years. Modern models can maintain comfortable temperatures down to -15F (-26C). Lots of happy customers in this reddit thread: https://www.reddit.com/r/heatpumps/comments/146jg7k/cold_cli...

This would not work in Chicago.

Chicago days under -15°F since 2015:

  Jan 18, 2016 -21°F Coldest day of that winter
  Dec 19, 2016 -21°F Early-season Arctic outbreak
  Dec 27, 2017 -19°F Part of a prolonged late-December cold wave
  Jan  2, 2018 -23°F Deep freeze to start the year
  Jan 30, 2019 -30°F Coldest Chicago temp since 1985; “Polar Vortex” event
  Feb 14, 2020 -18°F Valentine’s Day Arctic blast
  Feb  7, 2021 -21°F Mid-winter cold snap
  Dec 23, 2022 -23°F Pre-Christmas Arctic front
  Feb  3, 2023 -17°F Last occurrence to date
So basically every year.

edit: downvoted for noticing that it is cold.

Re: Harnessing America's heat pump moment

#39

Earlier quoted context omitted.

This is outdatated nonsense, I had my system installed 10 years ago and it works down to -15F... even the cheap $1k systems on Amazon work below freezing now Like any piece of equipment, just check the specs before you buy...

What’s the COP at -15F? It’s probably close to 1, which means you’re paying for resistive heat which happens to be the most expensive possible way to heat something up.

A Mitsubishi Hyper-heat MXZ-4C36NAHZ for instance has a COP of 2.12 at -13F outdoor temp and 70F indoor temp.

Re: Harnessing America's heat pump moment

#40

> we’re waiting on people Right on. I have a heat pump water heater and a heat pump heating system in my HVAC. Getting those installed felt like swimming upstream. Most contractors would try to dissuade me from them. Luckily, I found a contractor who was skilled and knowledgeable about heat pumps and rebates (back when govt thought climate change was real). Very happy with my heat pump tech.

I ended up self-installing my HP-WH. Professionals either tried to talk me out of it like you described, or charged a premium for the upgrade. My county has a rebate that allows for self-installs. It was rather straight forward and ended up being ~$700 in the end. The old unit I tore out took an extra $350/year in electricity, so I've already broken even.
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