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Harnessing America's heat pump moment

heatpumped.org

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Re: Harnessing America's heat pump moment

#161

Post by throw0101a »

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…

> 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.

When was the heat pump manufactured? Mitsubishi, for one, publishes data were they have 100% heating capacity at -15C, which some models being 100% at -20C and -23C:

* https://www.mitsubishielectric.ca/en/hvac/home-owners/zuba

There's a website for cold climate air-source heat pumps (ccASHPs), that has performance data down to (at least) 5F/-15C:

* https://neep.org/heating-electrification/ccashp-specificatio...

* https://ashp.neep.org/#!/

OEMs can optionally have publish data on "Lowest Cataloged Temperature" if it's below 5F/-15C.

Also: how (air) leaky is your house? how much insulation? For a lot of folks dealing with those two things would be more cost effective than anything.

As it stands, even if you are heating with "cheap" methane (née 'natural') gas, propane, or oil, you're throwing money out the window by letting the heat out in winter. (And the heat in / cold out in the summer.)

Re: Harnessing America's heat pump moment

#162

Post by yojo »

sitharus wrote: post #146
darth_avocado wrote: post #57

Earlier quoted context omitted.

I’m in California, I have two heat pumps installed. I can sum up the problems as follows: 1. They are EXPENSIVE. The equipment itself isn’t that expensive tbh but installation is pretty expensive. The government subsidies have made sure that the contractors jack up their own prices by as much. 2. I end up paying more in utilities because electricity is very expensive and heat pumps aren’t nearly as good at heating in…

I was shocked when I saw the price of heat pump installation in the US, even with an existing ducted system. There’s no reason a reversible heat pump system should be significantly more expensive than a cooling only one.

It’s bonkers. I bought a pre-charged ductless mini split to DIY. Took my dad and I about four hours to do the install. So call it 8 hours of semi-skilled labor.

The unit was $1350, I added a line set cover, pad and feet for another $200, and needed about $200 in electrical equipment - it was a long wire run and code requires installing a disconnect box. The only special tool was a hole saw bit for running the coolant lines.

So maybe $1850 all-in, plus 8 hours labor. I’m sure a pro could do it in half the time. But the low end for a pro install is $5k.

I get that they have insurance and warranty or whatever, but that’s a damn juicy margin.

Re: Harnessing America's heat pump moment

#163

Post by sokoloff »

doctorhandshake wrote: post #153
sokoloff wrote: post #150

Earlier quoted context omitted.

100% efficiency is terrible for a heat pump. Electric resistance heat is 100% efficient.

I should have said 100% performance. COP is typically 3-4:1 with mitsu

Typical seasonal average? Sure.

At -5°F? Hell no!

At +5°F, they rate their own equipment to have a 2.0 CoP.

https://mylinkdrive.com/viewPdf?srcUrl=http://s3.amazonaws.c...

Re: Harnessing America's heat pump moment

#164

Post by crgwbr »

kragen wrote: post #136
crgwbr wrote: post #106

Earlier quoted context omitted.

That’s true, but still doesn’t always make heat pumps the most cost effective choice to operate. For example, last winter I paid an average of $0.24/kWh for electricity vs $0.05/kWh for natural gas. Even if a heat pump had a perfect 4.0 COP all winter, gas would be ~15% cheaper. Electricity prices really need to come down before it will be viable for everyone.

Get solar.

I’ve tried. For it to be at all viable on my property, I’d need to cut down a bunch of trees. I’d rather keep the trees and pay someone else with solar panels.

Re: Harnessing America's heat pump moment

#165

Post by parpfish »

morshu9001 wrote: post #127
darth_avocado wrote: post #107

Earlier quoted context omitted.

> most homeowners in california actually see operating cost parity or a slight decrease, even with super expensive electricity But you’re missing my first point though, installing a heat pump system comes with a price tag of tens of thousands of dollars. I’m not doing that if my operating cost is at parity or a slight decrease. It’s the same reason people are no longer incentivized to install solar. And to add to tha…

I feel like home solar makes no sense without subsidies, even now with economies of scale. Commercial solar may be a different story.

home solar makes sense when you live out in the boonies and there's an unreliable grid that goes down in storms

Re: Harnessing America's heat pump moment

#166

Post by wtallis »

pessimizer wrote: post #38
nsxwolf wrote: post #23

Earlier quoted context omitted.

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…

What's relevant is not how cold it got on the coldest day of the year, but how warm it got on the coldest day, and how long it stayed cold. If the daytime high is mild enough that an undersized heat pump can keep the house at 72, it will take time for that house to cool from 72 to eg. 63 when the temperature drops overnight. And since the heat pump is still trying to keep the house warm, it'll take a lot longer for the house to cool off than if the heat were turned off entirely.

Re: Harnessing America's heat pump moment

#167

Post by throw0101a »

sokoloff wrote: post #163
doctorhandshake wrote: post #153

Earlier quoted context omitted.

I should have said 100% performance. COP is typically 3-4:1 with mitsu

Typical seasonal average? Sure. At -5°F? Hell no! At +5°F, they rate their own equipment to have a 2.0 CoP. https://mylinkdrive.com/viewPdf?srcUrl=http://s3.amazonaws.c...

Here's a Trane/Mitsubishi unit that has a COP of (at least) 3 at -13F/-25C:

* https://ashp.neep.org/#!/product/156605/7/25000/95/7500/0///...

An LG unit with 2.4 at -4F/-20C:

* https://ashp.neep.org/#!/product/29688/7/25000/95/7500/0///0

Searchable database of cold climate air source heat pumps (ccASHPs):

* https://ashp.neep.org/#!/product_list/

Re: Harnessing America's heat pump moment

#168

Post by bluGill »

switchbak wrote: post #92
bluGill wrote: post #50

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 wor…

It's really amazing how often I hear that same story: poor choices by the installer left the home owner in a bind with a poorly functioning system. The industry (certainly the residential side) really does need better educated installers/planners. Even as a homeowner who's a bit of an energy geek, it's entirely too challenging to understand the entire space and what options fit one's needs. LLM's help a lot here (if…

The system works well - just not how I want it. I was expecting to need the gas heat 1-2 weeks per year not 2-3 months.

Re: Harnessing America's heat pump moment

#169

Post by chongli »

danielsju6 wrote: post #148

Maybe I have scar tissue from COVID prices but $20k to install a ductless heat pump vs. a $200 to throw a window A/C in or $700 for a portable heat pump. While I get that these heat pumps are better for the environment and much more efficient it's a last mile issue. The installers charge an arm and a leg and I'm not hurting enough to self install. I'm hoping the window heat pumps that just run off mains will be avail…

This is talking about cold-climate heat pumps. A $200 window AC isn't going to heat your house when it's way below freezing outside.

$20k USD is insane though. I live in Ontario and we paid $12k CAD (pre-government subsidy) for a modern heat pump with a backup high efficiency furnace for when temperatures dip down to -40 or lower.

Re: Harnessing America's heat pump moment

#170

Post by kevin_thibedeau »

morshu9001 wrote: post #127
darth_avocado wrote: post #107

Earlier quoted context omitted.

> most homeowners in california actually see operating cost parity or a slight decrease, even with super expensive electricity But you’re missing my first point though, installing a heat pump system comes with a price tag of tens of thousands of dollars. I’m not doing that if my operating cost is at parity or a slight decrease. It’s the same reason people are no longer incentivized to install solar. And to add to tha…

I feel like home solar makes no sense without subsidies, even now with economies of scale. Commercial solar may be a different story.

If you DIY everything and go with server rack batteries you can keep the costs low enough for a reasonable break even point. Any middleman is going to gouge.
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