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Harnessing America's heat pump moment

heatpumped.org

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Re: Harnessing America's heat pump moment

#41

Post by quickthrowman »

atrus wrote: post #25
andrewvc wrote: post #11

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.

A possible challenge, yes, but there exist 1500w, standard outlet hpwh, and it's a lot less common to not have any power near a water heater.

A 1500W electric water heater would be painful to use in a home. A typical 30-60 gallon EWH is 6kW.

And for the record, every single natural gas water heater is connected to 120V power for the ignition circuit.

Re: Harnessing America's heat pump moment

#42

Post by VWWHFSfQ »

mithr wrote: post #26

Electricity costs are a big factor in this, imo. Rates for my northeast town increased by ~25% in 2024 and are going up by another ~10% this year. It's a hard sell to spend a large amount of up-front money (even after rebates, which decreased this year) to convert to a system that will cost you more than you pay today, and may not work as well in cold weather (every heat pump company I talked to suggested keeping my…

A heat pump just makes no sense whatsoever for me in my northeast town. The electric bill alone would outpace the old propane bill, not to mention installation.

And it won't even work during some of the coldest winter weeks when you _really_ need it to work.

Maybe I would consider it if I was in, like, Nevada or somewhere.

Re: Harnessing America's heat pump moment

#43

Post by Glyptodon »

brendoelfrendo wrote: post #27
galoisscobi wrote: post #3

> 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 guess I lucked out; our house had a (very old) whole-home (that is, ducted) heat pump system for heating and cooling when we moved in. When it was time to replace, our local contractor knew exactly what we needed. They even do mini-splits, had we wanted one.

Do newer ones somehow not need ducts?

Edit: (or so you mean mini splits?)

Re: Harnessing America's heat pump moment

#44

Post by quickthrowman »

RealityVoid wrote: post #37
quickthrowman wrote: post #31

Earlier quoted context omitted.

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.

That’s +15F, what’s the COP at -26C?

Re: Harnessing America's heat pump moment

#45

Post by prlambert »

nsxwolf wrote: post #22

When I needed a new air conditioner I looked into heat pumps. 3x the price.

That seems really weird, the only real difference is a reversing valve that costs a couple bucks. A heat pump is an AC, it just can be run backwards to produce heating as well. In cooling it's literally the same thing.

Re: Harnessing America's heat pump moment

#46

Post by jjtheblunt »

wffurr wrote: post #29
nsxwolf wrote: post #22

When I needed a new air conditioner I looked into heat pumps. 3x the price.

That's crazy. It's a reversing valve. But you might also be comparing multi-stage variable load DC heat pumps with single stage air conditioners and not an actually equivalent air conditioner.

or local sellers are incentivized profitably to push old technology air conditioners?

Re: Harnessing America's heat pump moment

#48

Post by lbotos »

blahedo wrote: post #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 mi…

What brand and was it sized for winter load?

Im in NY, 6 heads across 3 floors with 2 heads per outdoor unit. 2500sf covered.

Mitsubishi h2i (i think im on my phone). Get plenty warm in the winter as my sole heat source. I could have gotten smaller outdoor units and had resistive backup but I didn’t want that.

Re: Harnessing America's heat pump moment

#49

Post by quickthrowman »

SigmundA wrote: post #39
quickthrowman wrote: post #31

Earlier quoted context omitted.

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.

That’s actually a lot better than I expected, thanks!

Re: Harnessing America's heat pump moment

#50

Post by bluGill »

When I replaced my furnace a couple years back I asked for a heat pump - a previous house had it and it worked great. Turns out my contractor didn't ask the right questions and so mine only works to 25F - it still outputs heat below that, but not enough to keep my house warm and so I use the backup furnace a lot more than I want to.

A previous house the heat pump was sized to work to 14F. They make them that will work down to -25F, but since it gets to -30f where I live (about once every 10 years, but that is enough) we need a backup system so is probably isn't worth getting a system sized to as cold as possible.

Ground source heat pumps are a common option in rural areas - they cost a lot to install ($50k - and this is the cheapest version that needs a lot of land thus rural areas). They are likely to pay off if you live in the same house for 50 years, but the initial upfront costs are high (you do get a house worth $10k more than other heat option). Worth looking into if you are young and have reason to think you will live in the same house for 50 years.

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