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Heat Pumps – The Well-Tempered Future of A/Cs

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Re: Heat Pumps – The Well-Tempered Future of A/Cs

#81

Post by Maxburn »

kevin_thibedeau wrote: post #38
Maxburn wrote: post #23

Earlier quoted context omitted.

It's an industry term for mechanical equipment that can heat AND cool. One piece of equipment replaces your AC AND heat source. Heat pumps in particular are getting a push from "green" initiatives because they only use electricity for fuel which can potentially be supplied by "renewable" sources. ie; it's a buzz word.

It's not just buzz. It's more efficient than resistive heating and modern units have better performance in cold temps. Hence the push to promote them. The downside is that you have added complexity driving up installation costs and reliability down.

Walk around in the American Heating and Refrigeration conference for a while to get a feel of these trends, this was specifically called out by many manufacturers as driven by the green movement.

Re: Heat Pumps – The Well-Tempered Future of A/Cs

#82

Post by nemo44x »

davidmurdoch wrote: post #64
nemo44x wrote: post #20

I have both HVAC and a ducted heatpump for one part of the home. The biggest issue with the heatpump is that in the climate I live in there are times of year where you may have the heat on in the morning and the AC in the afternoon. Or you may leave and when you return you want to change the temperature. A furnace and an AC can do this rapidly. A heatpump takes time. It's more of a trickle of climatized air than a bl…

Mine take maybe 2 minutes to switch from heating to cooling, or cooling to heating.

I’m saying the time it takes to change the temperature in the home, not the time to switch function.

Re: Heat Pumps – The Well-Tempered Future of A/Cs

#83

Post by colechristensen »

silisili wrote: post #10
digdugdirk wrote: post #2

Well this was an oddly terrifying introductory paragraph for an IEEE article: "... half of Phoenix residents are at risk of an emergency room visit or worse if their electricity fails during a future heat wave, according to a recent study. Air conditioning is what keeps people there comfortable—and alive—a growing fraction of the year. The extreme heat already kills hundreds of Phoenix-area residents every year, a nu…

Sure, but it can happen anywhere. I was just reading yesterday about a person who died in Portland of heat during the dome. Same with cold weather, if the gas/electric goes out during the winter. There's really only a few places one can live with moderate enough weather to avoid those scenarios.

Eh, it is much much easier to keep warm when it's -40 outdoors than it is to keep cool when its 120+ outside.

Unless you have a terribly insulated shelter, blankets, coats, and friends will keep you warm enough to the extent that unless you are not really capable of taking basic care of yourself, you're not dying of the cold when your heat goes out. You can always do more insulation, and you only need so much for your body to keep you warm.

With heat though you run out of things to do.

There is a difference between an impaired person or a person doing something unwise dies of the heat or cold... and there being an environment where there's nothing a healthy adult can do to survive without powered heating/cooling.

Re: Heat Pumps – The Well-Tempered Future of A/Cs

#84

Post by elil17 »

__MatrixMan__ wrote: post #62
elil17 wrote: post #41

Earlier quoted context omitted.

There's no reason you couldn't just switch a couple valves out in your AC and perhaps change the refrigerant to make it into a serviceable heat pump. However, you'd need to retrofit controls/electronics, which I don't think most HVAC technicians would know how to do. It's also not advisable to attempt to DIY something like this because it is very easy to accidentally vent the refrigerant, which is a very potent green…

Right. It's a problem best confronted by the AC manufacturer. Except they have no incentive to do so (because if they don't, they get to sell an entirely separate heat pump down the line). Which means it's perhaps a problem for the regulator. There are tax breaks involved with installing "energy star" rated equipment. Perhaps we ought to start witholding the star from AC units that are not easy to convert to heat pum…

I think that would be an excellent regulatory solution. You should write to your representatives. Since heat pumps are getting a lot of regulatory attention, it might actually get considered.

Re: Heat Pumps – The Well-Tempered Future of A/Cs

#85

Post by triceratops »

afavour wrote: post #72
brabel wrote: post #54

Earlier quoted context omitted.

Do you think people shouldn't be living in Chicago (or most of Canada and the US midwest for that matter) because without heating it's just completely inhospitable to human life during the winter? Or pretty much all Australian cities in summer?

Heating is considerably more energy efficient than having to run ACs all over the place. And if you need to go outside when it's cold you can: you add layers of clothing. In Arizona, in the middle of summer, you could be buck naked and you'd still overheat (and get burnt, to boot).

> Heating is considerably more energy efficient than having to run ACs all over the place.

That's actually incorrect. Heating takes considerably more energy.

When you're cooling you're looking at a temperature delta of at most 20 degrees C/45 degrees F between outside and inside. When you're heating, it can be easily be twice that. Or even more, in parts of Canada or the Great Lakes states.

Air conditioning is a heat pump and can achieve up to 300% efficiency. Whereas most houses in cold climates use furnaces, which have at most 98% efficiency.

Now that we have more efficient cold-climate heat pumps all of this may gradually change. But as of right now, what you're saying is wrong.

Re: Heat Pumps – The Well-Tempered Future of A/Cs

#86

Post by silisili »

phpisthebest wrote: post #59
silisili wrote: post #10

Earlier quoted context omitted.

Sure, but it can happen anywhere. I was just reading yesterday about a person who died in Portland of heat during the dome. Same with cold weather, if the gas/electric goes out during the winter. There's really only a few places one can live with moderate enough weather to avoid those scenarios.

>>Same with cold weather, I 100% disagree with this... Heat is made by everything, waste heat is a byproduct of all modern things, and there are TONS of easy low cost ways to make heat even it is just as simple as burning something. Also the body makes head naturally so adding layers to trap this heat does not require continual inputs from an outside resource Cooling on the other hand is MUCH harder, and electricity…

For a young/healthy person, sure. But these aren't generally the at risk people in the first place.

I grew up around the 38N parallel, gross enough to get too hot in the summer and too cold in the winter. Every winter people froze to death, just the same.

It's not as bad as Phoenix percentage wise, but it's still a risk in the vast majority of places that people in the US live.

Re: Heat Pumps – The Well-Tempered Future of A/Cs

#87

Post by Maxburn »

1-more wrote: post #47
Maxburn wrote: post #23

Earlier quoted context omitted.

It's an industry term for mechanical equipment that can heat AND cool. One piece of equipment replaces your AC AND heat source. Heat pumps in particular are getting a push from "green" initiatives because they only use electricity for fuel which can potentially be supplied by "renewable" sources. ie; it's a buzz word.

> because they only use electricity for fuel which can potentially be supplied by "renewable" sources. They also can operate at >100% efficiency. Under the right conditions (I'll let someone who knows more about it fill that in) they can provide more heat than the same amount of power going into a resistive heater (which is I think per-se 100% efficient right?). Kinda wild.

OR another (incorrect) way of thinking is that resistive heating is 100% efficient as every bit of heat generated is inside the home. VS mechanical heat has some "loss" with some of the heat being left outside the home.

But yes, mechanical might be up to 600% efficient depending on how you think about it as moving heat around based on energy usage per therm delivered inside the home is really what people are looking for.

Re: Heat Pumps – The Well-Tempered Future of A/Cs

#88

Post by Schweigi »

itzworm wrote: post #70
nemo44x wrote: post #20

I have both HVAC and a ducted heatpump for one part of the home. The biggest issue with the heatpump is that in the climate I live in there are times of year where you may have the heat on in the morning and the AC in the afternoon. Or you may leave and when you return you want to change the temperature. A furnace and an AC can do this rapidly. A heatpump takes time. It's more of a trickle of climatized air than a bl…

There are ceiling cassettes for mini-split systems that aren't nearly as much of an eyesore as the wall mount ones are.

Mini split systems can be used with ducts. All big venders sell heads which are specifically made to be connected to ducts. That way you get the best of both worlds and its also easy to retrofit to an existing (ducted) house.

Re: Heat Pumps – The Well-Tempered Future of A/Cs

#89

Post by Maxburn »

jondwillis wrote: post #39
Maxburn wrote: post #23

Earlier quoted context omitted.

It's an industry term for mechanical equipment that can heat AND cool. One piece of equipment replaces your AC AND heat source. Heat pumps in particular are getting a push from "green" initiatives because they only use electricity for fuel which can potentially be supplied by "renewable" sources. ie; it's a buzz word.

Why put renewable in quotes? Because it isn’t 100%?

Basically yes. Renewable is more of a supplement to current grids for most of us. There might be a couple rare few areas that currently claim 100%.

Re: Heat Pumps – The Well-Tempered Future of A/Cs

#90

Post by t8sr »

davidmurdoch wrote: post #69
ptmcc wrote: post #32

Earlier quoted context omitted.

Please stop with these sorts of posts, it's the 2023 equivalent of "let me google that for you"

Only if they used GPT 3.5, if they used GPT 4.0 is more like someone using their paid access to a subscription to a scientific journal to look up research papers for someone.

Not really - a scientific journal contains information of a high quality. The fact that money is involved here makes no difference. A better analogy would be using your paid subscription to a horoscope.
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