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Harnessing America's heat pump moment

heatpumped.org

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Re: Harnessing America's heat pump moment

#541

Post by CalRobert »

neltnerb wrote: post #491
CalRobert wrote: post #296

Earlier quoted context omitted.

Is there a reason to use radiators and not just go straight to air to air pumps, which also have aircon?

From context I can't tell if they mean the heated coils in a heat pump head, or somehow connecting to a traditional radiator. In older homes there isn't necessarily HVAC at all and instead there are actual radiators. I've lived in two like that, there is just no forced air to rooms.

Yeah, European homes seem to have a love of radiators that I don't really understand; I hate mine. Ugly and huge.

Re: Harnessing America's heat pump moment

#542

Post by CalRobert »

stavros wrote: post #316
antonymoose wrote: post #315

Earlier quoted context omitted.

One question I would have is how distorted is your area, economically? I live in the Appalachian mountains, so one would think it should be reasonable labor rates for an area with a middle-low cost of living. Except that we have a lake the next town over which is entirely covered in millionaire lake houses, so anyone working a trade here can and will charge obscene rates to local, normal people because they can comma…

You've kind of exposed me, I'm not in the US, my question was in the first person but it was more that I'm curious as to the causes of what the commenters report. You may be right about the area just being HCoL, though.

Note that in some places (the EU for instance) self-installation is illegal since you need an F-gas certified installer. Of course, this may result in higher emissions than letting people DIY it, since it discourages switching away from gas....

Re: Harnessing America's heat pump moment

#543

Post by TeMPOraL »

caminante wrote: post #468
TeMPOraL wrote: post #454

Earlier quoted context omitted.

"Whataboutism", like "dog whistle", is a name for an imaginary discussion pattern that doesn't occur in real life, but is super easy to point out in most conversations, allowing one to cry foul and "win" the argument (or whole discussion) through violence instead of reason. This is pretty much the same as accusing a colleague of insulting you through PR they asked you to review, because there's an added line that say…

? [0] [0] https://en.wikipedia.org/wiki/Whataboutism

What about it?

Re: Harnessing America's heat pump moment

#544

Post by throw0101a »

ssl-3 wrote: post #499
whateveracct wrote: post #403

Earlier quoted context omitted.

I think the comment was saying below 30F and below 10F. Much warmer than you're saying. Also.. > It is warmer than -16C/3F at Chicago (O'Hare) for 99% of the time (i.e., except for 4 days a year), and warmer than -18.7C/-2F for 99.6% of the time (2 days). If my heat doesn't work for those days, I'm kind of boned. Four days per year without a working heat pump? That's a mess.

At face value, then in the worst case that's just 4 days per year of using resistive heat to keep a home warm. Which is, of course, very expensive to use -- but it's only expensive for those 4 days. Resistive heat can be avoided for the other 361.2425 days in a year. In the US (as of August of 2025), the average price of residential electricity per delivered kWh is $0.1762 [1]. If using resistive heat averages 4kW du…

> At face value, then in the worst case that's just 4 days per year of using resistive heat to keep a home warm.

The design philosophy for using 1% is that you may end up having to run your heating (or cooling) 24/7 to keep up with temperature delta between outside and desired inside, but it will keep up with the demand.

The rest of the time (99%) the mechanicals only run intermittently. Also note that the 1% would not necessarily occur every year: it is just the historical average. The charts also have the 0.4% extremes if you want to be extra conservative, but most building codes specify 1% because that is what experience has shown is a good trade-off.

Part of the process (in the US) is to use what is called the Manual J to determine/estimate/calculate how much energy is needed to maintain a particular temperature (typically ≥70F/21C in winter, ≤75F/24C in summer):

* https://www.acca.org/standards/technical-manuals/manual-j

* https://www.youtube.com/@HomePerformance/search?query=Manual...

> The Cooling Design Day is effectively the "worst case" day for your air conditioning loads. The "worst case" hour of this day determines equipment capacity, fan sizes, and subsequently duct sizes. This largely impacts first cost. The Design Hour also impacts peak KW demand which often has a huge impact on the utility bill.

* https://energy-models.com/blog/hvac-what-cooling-design-day

* https://hvac-blog.acca.org/sizing-selecting-hvac-equipment-p...

* https://www.airequipmentcompany.com/2021/what-does-design-da...

Here's an overview of the design process for one particular municipal jurisdiction:

* https://www.suffolkva.us/DocumentCenter/View/7362/Understand...

Re: Harnessing America's heat pump moment

#545

Post by Krispy805 »

I am a HERS Rater and Title 24 Consultant in California. Our State Government hyped the idea of replacing every unit in California with Heat Pumpsnover 2p years. Unfortunately the big cookie cutter new home developers did not really like the idea. Sonthey installed 80% efficient old fashioned gas firwd furnaces like usual in 90% of new homes since 2015. Heat pumps are flashy, but most models do not handle cold weather. Units that use R410A will not ever peoduce heat in the true sense of the word. They are much more efficient at cooling however they simply cannot produce meaningful amounts of heat. HP Units that run on CO2 (R-0) as a refrigerant have been used in Alaska winters to provide emergency heat. The extreme performance difference between R410A and R0 is so staggering that one might wonder why R22, R134, R500 or R410A were ever used in thebfirst place. That has to donwith patent law and stubborn, lead poisoned engineers. Ya I said it, anone born before 1980 is a retard with Lead Poisoning. Get over it boomer, nobody respects you cause you lead in your soft tissue!

Anyways, if you feel like running the AC, then go outside. It is much hotter in Mexico, think about that.

Re: Harnessing America's heat pump moment

#546

Post by Shog9 »

Scene_Cast2 wrote: post #362
bluGill wrote: post #331

Earlier quoted context omitted.

Indoor propane furnaces exhaust outdoors in most cases. Space heaters that exhaust indoors are rare - more used for garrage heat than house. If you use them of course actount for it, but most are not.

Theoretically yes, in practice no. There is (according to my sensors) a fairly large CO2 increase inside a room when a modern furnace (with external exhaust) is running. I've confirmed this with several units (all made in the last 10 years), and it's not that the windows are closed - when the furnace turns off, the CO2 drops. And it's not that the exhaust is placed in a bad spot either.

Your control for this test should be (and maybe was, you don't say) running the furnace circulation fan without running the burner. CO2 levels are unlikely to be uniform throughout a building, and thus mixing will change (raise, lower) the CO2 levels depending on where you're measuring.

Re: Harnessing America's heat pump moment

#547

Post by glxxyz »

dns_snek wrote: post #533
glxxyz wrote: post #443

Earlier quoted context omitted.

I’m not sure what you mean by ‘unsustainable’ nor ‘critical mass’ here. Of course not everyone can net meter- on a sunny but mild day with no-one using A/C nor heating and everyone contributing back to the grid it doesn’t work. My local utility is well aware of that, applications for permits to net meter have to be made, and only a fraction (something like 15%) of properties in each area can net meter. Also the gover…

Sorry, I should've been more specific, I can explain. > My local utility is well aware of that, applications for permits to net meter have to be made, and only a fraction (something like 15%) of properties in each area can net meter. Okay, that changes things. The way it worked here is that anyone in the country could install solar and get grandfathered into net metering (perpetually), and then at a certain point the…

That makes more sense, but your utility's failings are not necessarily the same as mine nor anyone else's.

I wish I'd never mentioned solar nor net metering now- I'm not on some crusade to promote either, I was just explaining the economics of my personal setup.

Re: Harnessing America's heat pump moment

#548

Post by glxxyz »

Marsymars wrote: post #464
glxxyz wrote: post #186

Earlier quoted context omitted.

I'm amazed at these prices, I replaced a propane tank + furnace with horizontal loop ground source for $40k Canadian (+ tax, but government rebate matched that). It's almost paid for itself in about 6 years, I gave more detailed numbers in another reply.

Your setup sounds great, but depending on location in Canada, gas can be much cheaper than propane. I just priced running a gas line for my BBQ, and I'd break even on a $500 install cost after about 40 20lb propane tank fills.

Yes the calculations are different for natural gas, I don't have that option. Rural properties here (south/central Ontario) typically use delivered oil or propane supplemented by firewood.

I recently thought about running a BBQ gas line from my main 500 gallon propane tank, but with delivered propane close to $1/litre right now and a 20lb tank holding about 18 litres there's no saving over just using with the portable tanks. I prefer being able to move the barbecue around too, although I probably would run a line if I had an outdoor kitchen type setup.

Re: Harnessing America's heat pump moment

#549

Post by kortilla »

neltnerb wrote: post #472
kortilla wrote: post #238

Earlier quoted context omitted.

Then why aren’t they in 2/3 of houses

I listed a reason that impacts a third of houses. I didn't write an essay because the article lists plenty of others. It was just weird that they never mentioned the misaligned incentives.

They didn’t mention them because they clearly aren’t a dominating factor.

Re: Harnessing America's heat pump moment

#550

Post by baggy_trough »

maxerickson wrote: post #65
baggy_trough wrote: post #63

Earlier quoted context omitted.

It wasn't a bad experience before, but now it is, because of: new heat pump

Well what capacity does each system have? That they came back and added resistive heating suggests your contractor may not have been too worried about sizing the system correctly in the first place.

Seems like it's harder to correctly size a heat pump system, perhaps because it costs more if right sized, if it's even possible to right size it at all.
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