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Harnessing America's heat pump moment

heatpumped.org

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Re: Harnessing America's heat pump moment

#81

Post by harshreality »

quickthrowman wrote: post #41
atrus wrote: post #25

Earlier quoted context omitted.

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.

I think this is right...

kwatts_effective [kJ/s] * heating_time_minutes [min] * 60 [s/min] * COP = 4.184 [kJ/kg/K] * (T₁-T₀) [K] * gallon_capacity [gal] * 3.785 [L/gal] * 1 [kg/L]

6.6 kW, for... COP 4, T₁-T₀ = 30 [K] (lower value for warm climate), allowable 30 minute heating time, 50 gallon capacity. A cold climate could double that power requirement, or alternatively double the heating time.

Re: Harnessing America's heat pump moment

#82

Post by maxerickson »

quickthrowman wrote: post #41
atrus wrote: post #25

Earlier quoted context omitted.

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.

It's not uncommon for a gas heater to have an always on pilot.

Re: Harnessing America's heat pump moment

#83

Post by micromacrofoot »

quickthrowman wrote: post #31
micromacrofoot wrote: post #4

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.

Yeah most places aren't consistently -15F, not going to be a dealbreaker for a week.

If you live in Minnesota stick with gas, we'll be ok. The majority of the population will never hit -15F.

Re: Harnessing America's heat pump moment

#84

Post by micromacrofoot »

VWWHFSfQ wrote: post #30
christophilus wrote: post #13

Earlier quoted context omitted.

63 when it’s -5 out seems totally fine. More than fine for much of the US.

Maybe totally fine for you. But that will not be "totally fine" for much of the US when they are expecting to keep their house at 72 degrees and the new technology they got talked into can't do it. The tech has limits and cold weather states can't avoid that or the reputation will get really bad and the tech will fail.

I'm not sure if you've lived in prolonged -15F areas, but many conventional heating systems struggle too... especially in poorly insulated houses. People often have wood stoves or other ways to compensate.

Re: Harnessing America's heat pump moment

#87

Post by supportengineer »

TimTheTinker wrote: post #77

All this push to electrify everything makes me nervous, as it effectively centralizes a lever that someone evil enough could use to coerce the general public in unsavory ways. I'm doubly suspicious of areas that combine mass-electrification with reducing availability of the most reliable alternate source of electricity (i.e. generators). California in particular is pushing to make generators increasingly hard to obta…

>> someone evil enough

There's so much evil being demonstrated today, in real time, that we can't dismiss this any more, it must be seriously considered.

Re: Harnessing America's heat pump moment

#89

Post by switchbak »

prlambert wrote: post #54
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…

Yes this is actually the worst – when open minded people get a heat pump for "the right reasons" and then have buyer's remorse. Completely backfires the transition. Do you have a ducted or ductless heat pump? Sounds like ducted, and if so that might be part of it too. The air cools down in the ductwork and if that's not accounted for - i.e. you reuse ductwork that was meant for a furnace – you run into issues like th…

Hi Paul - I'm a big fan of Quilt from Vancouver Island.

It seems to me that you're helping to close the loop on some of the quality concerns that the parent commenter has. Inappropriate sizing/installation and poor product selection seem like common issues from HVAC installers that aren't particularly well versed on heat pumps.

Wishing you continued success, and that hopefully it'll be available in Canada at some point! And also I remember you from the Scala meetup in Vancouver :)

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