Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Nine US states are teaming up to accelerate the adoption of heat pumps

wired.com

Post reply on HN
Print view View original

21–30 of 766 posts

Re: Nine US states are teaming up to accelerate the adoption of heat pumps

#21

Post by rootbear »

vundercind wrote: post #2

> Death is coming for the old-school gas furnace—and its killer is the humble heat pump. Uh, you still need a furnace (though it could be electric) if you live somewhere that ever really gets cold, right? [edit] I mean, seeing it presented as a furnace replacement is weird to me. I’ve always seen it sold as an air conditioner replacement that also happens to heat (with weird characteristics that often confuse people—…

I live in Maryland and the first townhouse I owned, in the late 80s to early 90s, had a heat pump. It included an auxiliary electric heater for days that it got really cold. I don't remember it coming on all that often. (There was a light on the thermostat to indicate when it was on.) My current townhouse has a gas furnace. I plan to move soon into a single level home, more appropriate for an old greybeard, and I'll have to evaluate then if I want to switch to a heat pump, if the house doesn't have one already.

Re: Nine US states are teaming up to accelerate the adoption of heat pumps

#22

Post by rimunroe »

vundercind wrote: post #2

> Death is coming for the old-school gas furnace—and its killer is the humble heat pump. Uh, you still need a furnace (though it could be electric) if you live somewhere that ever really gets cold, right? [edit] I mean, seeing it presented as a furnace replacement is weird to me. I’ve always seen it sold as an air conditioner replacement that also happens to heat (with weird characteristics that often confuse people—…

Note: this is only true for air-source heat pumps. Ground source-heat pumps aren't affected by ambient air temperature, but they're also much more expensive and require suitable ground. Also, I hear air-source heat pumps have made significant advances lately in how well they handle sub -15 °C temperatures.

Re: Nine US states are teaming up to accelerate the adoption of heat pumps

#23

Post by mikeyouse »

vundercind wrote: post #2

> Death is coming for the old-school gas furnace—and its killer is the humble heat pump. Uh, you still need a furnace (though it could be electric) if you live somewhere that ever really gets cold, right? [edit] I mean, seeing it presented as a furnace replacement is weird to me. I’ve always seen it sold as an air conditioner replacement that also happens to heat (with weird characteristics that often confuse people—…

> Uh, you still need a furnace (though it could be electric) if you live somewhere that ever really gets cold, right?

For now - and only in part of the country. Most of the newest models can output 100% of their rating down to something like -5ºF -- they're easy enough to oversize as well, so if your 99% heating load is e.g. 48,000BTU, a 60,000BTU heat pump that's only outputting 80% of rated BTUs due to the extreme cold can still cover the full design load.

Here's the spec sheet for the newer Mitsubishi hyper heat models - 87º output at -4ºF and 76% output at -13ºF -- very few places in the states ever get that cold: https://static.appliancesconnection.com/attachments/D5bf5709...

Re: Nine US states are teaming up to accelerate the adoption of heat pumps

#26

Post by jacobolus »

danans wrote: post #8

A big issue right now is the oversizing of heat pumps by HVAC contractors who are used to sizing gas furnaces using very simple btu/hr/sqft calculations. A contractor should do some kind of heating need analysis, at the least by studying old utility bills, and ideally by doing a Manual J heat loss calculation for the house. But almost none of them do that. There are some startups attempting to handle these design ste…

Can you explain why this is a big issue?

Re: Nine US states are teaming up to accelerate the adoption of heat pumps

#27

Post by mrpopo »

chankstein38 wrote: post #25

Thank you, that's all I really cared about but I had "read my last free article" so I couldn't even find that out. I'm so tired of the internet.

I want a "Netflix of information". Let me pay 30€/month for unlimited information access, quality, no clickbait and no ads.

Of course, seeing what happens with Netflix now, I guess it wouldn't last long until things turn back to the old way...

Re: Nine US states are teaming up to accelerate the adoption of heat pumps

#28

Post by lotsofpulp »

mikeyouse wrote: post #23
vundercind wrote: post #2

> Death is coming for the old-school gas furnace—and its killer is the humble heat pump. Uh, you still need a furnace (though it could be electric) if you live somewhere that ever really gets cold, right? [edit] I mean, seeing it presented as a furnace replacement is weird to me. I’ve always seen it sold as an air conditioner replacement that also happens to heat (with weird characteristics that often confuse people—…

> Uh, you still need a furnace (though it could be electric) if you live somewhere that ever really gets cold, right? For now - and only in part of the country. Most of the newest models can output 100% of their rating down to something like -5ºF -- they're easy enough to oversize as well, so if your 99% heating load is e.g. 48,000BTU, a 60,000BTU heat pump that's only outputting 80% of rated BTUs due to the extreme…

I like the redundancy of natural gas. So far, in less than 40 years, I have been kept warm for multiple days on 3 separate occasions by having access to gas while the electricity did not work. Also, I was able to keep cooking.

One of the states in the article is Oregon too, where I have family that just a few weeks ago lost electricity for 4 days, but were able to use an electric generator to keep the air handler going and gas to heat the the house and cook.

I fear heat pump only heat will fail exactly when I most need it not to.

Re: Nine US states are teaming up to accelerate the adoption of heat pumps

#29

Post by 01HNNWZ0MV43FF »

vundercind wrote: post #2

> Death is coming for the old-school gas furnace—and its killer is the humble heat pump. Uh, you still need a furnace (though it could be electric) if you live somewhere that ever really gets cold, right? [edit] I mean, seeing it presented as a furnace replacement is weird to me. I’ve always seen it sold as an air conditioner replacement that also happens to heat (with weird characteristics that often confuse people—…

Technology Connections seems pretty happy with his. I think he lives in Chicago, admittedly not the coldest place, but it does snow every winter in that region.

He said 2.9 coefficient of efficiency average over a heating season for him - https://youtu.be/7J52mDjZzto?t=1522

Re: Nine US states are teaming up to accelerate the adoption of heat pumps

#30

Post by vundercind »

mikeyouse wrote: post #23
vundercind wrote: post #2

> Death is coming for the old-school gas furnace—and its killer is the humble heat pump. Uh, you still need a furnace (though it could be electric) if you live somewhere that ever really gets cold, right? [edit] I mean, seeing it presented as a furnace replacement is weird to me. I’ve always seen it sold as an air conditioner replacement that also happens to heat (with weird characteristics that often confuse people—…

> Uh, you still need a furnace (though it could be electric) if you live somewhere that ever really gets cold, right? For now - and only in part of the country. Most of the newest models can output 100% of their rating down to something like -5ºF -- they're easy enough to oversize as well, so if your 99% heating load is e.g. 48,000BTU, a 60,000BTU heat pump that's only outputting 80% of rated BTUs due to the extreme…

I’d say -15°F or lower is something you need to design for at least into the light-blue area on this map:

http://4.bp.blogspot.com/-tdK_AMaZ9pg/Vb51WrvPDhI/AAAAAAAAD5...

Which is quite a lot of the country.

Light blue is a typical Winter low point in the -10°F to 0°F, which means you will see -15°F or lower often enough to worry about it.

Post reply on HN