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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

#71

Post by __MatrixMan__ »

elil17 wrote: post #48
nightski wrote: post #26

Earlier quoted context omitted.

The thing is (especially where I live) I'd still need a gas furnace. We regularly see -20F to -40F in the winter. While the 95% scenario sounds great, in practice still needing gas means we still need all the gas infrastructure. From my understanding natural gas burns pretty clean. The problem is leaks in infrastructure and drilling, which isn't going away because I buy a heat pump.

Although natural gas is "clean" compared to, say, coal, the advantage of a heat pump is that it uses less total energy than natural gas. That means it would be more efficient to run a heat pump off a natural gas power plant than to burn natural gas to heat your home directly.

Where I live, you can bank solar credits. If you cash them out you get the "wholesale" energy price for them (much lower), but if you spend them on electricity then you've avoided paying full price for that electricity. So if your system produces more than you consume, you've got this free energy budget to spend--a budget that applies to heat pumps and not to gas furnaces.

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

#72

Post by afavour »

brabel wrote: post #54
afavour wrote: post #24

Earlier quoted context omitted.

I've only ever visited Phoenix but when I did it was mid July and being outside genuinely did not feel hospitable to human life. That statement doesn't surprise me at all. Unless you're employed in, I dunno, the solar power industry I really feel like you shouldn't be living there. It should be like living on an oil rig.

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).

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

#73

Post by elil17 »

ramesh31 wrote: post #34

Swamp coolers are massively underutilized as well. The vast majority of residential cooling in all but the most humid climates can be done with nothing but a fan and some cold water; no compressed gases necessary.

This sort of true? There are many hours per year in many climates where direct evaporative cooling alone could suffice to keep people comfortable. However, most climates also have a good number of hours where air conditioning is required for comfort.

You can use this tool to visualize this: https://drajmarsh.bitbucket.io/psychro-chart2d.html

(Use the Givoni Bioclimatic Chart overlay and select a weather station using the globe icon.)

That said, there are a number of more complex devices which could further reduce how often AC systems need to be used: dew-point (Maisotsenko Cycle) coolers, indirect evaporation cooling, and thermal energy storage to name a few.

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

#74

Post by willis936 »

ashconnor wrote: post #35
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…

I would imagine solar panels would be a good investment in a climate like this.

Or a solar boiler connected a refrigerant compressor. The hotter it gets the more cooling power you have. Steam punk for the 21st century.

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

#75

Post by [deleted] »

__MatrixMan__ wrote: post #15

I live in a colder climate where heat pumps are not popular. After talking with a number of HVAC people about this I was surprised to learn that despite being very similar to an AC system in principle, in practice converting an AC system into a heat pump system doesn't make economic sense--you end up just ripping one out and installing the other. I don't fully understand why this is the case, but I hope that there's…

[deleted]

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

#76

Post by AlbertCory »

RationPhantoms wrote: post #36
tiahura wrote: post #16

Earlier quoted context omitted.

Half of Phoenix vs A person in Portland. It seems like there’s an important scale issue there. So the risk isn’t really the same everywhere.

Good point on the scale. However, Phoenix is also a retirement destination so you're looking at a larger portion of the population being susceptible to heat waves.

> Phoenix is also a retirement destination

People who retire there most likely go up to Flagstaff in the summer, or further north.

Or they just have good A/C.

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

#77

Post by earlyriser »

__MatrixMan__ wrote: post #15

I live in a colder climate where heat pumps are not popular. After talking with a number of HVAC people about this I was surprised to learn that despite being very similar to an AC system in principle, in practice converting an AC system into a heat pump system doesn't make economic sense--you end up just ripping one out and installing the other. I don't fully understand why this is the case, but I hope that there's…

I live some 5 hours north of Montreal, we have few days at -40C and wall radiators (not sure about the name) are needed, but for most of the winter days we use the heat pump to heat the house (-21C and up). Some members in my family work in AC/Refrigeration industry and all of them have thermo pumps, which make economic and ecologic sense. On the other side I don't know about AC/heat pump replacements as it's not common to have AC for the just a handful of days that could be very hot.

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

#78

Post by chickenpotpie »

brabel wrote: post #54
afavour wrote: post #24

Earlier quoted context omitted.

I've only ever visited Phoenix but when I did it was mid July and being outside genuinely did not feel hospitable to human life. That statement doesn't surprise me at all. Unless you're employed in, I dunno, the solar power industry I really feel like you shouldn't be living there. It should be like living on an oil rig.

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?

I haven't formed an opinion on the matter yet, but I do think there's a large difference between it being too cold and too hot.

If I'm too cold and my power goes out I have a lot of options to survive. I can put on more clothes, get under a blanket, light my furniture on fire, etc

If I'm too hot and my power goes out, I die. Once the wet bulb temperature gets above a certain level in shade, there's nothing that can be done to stop me from dying except Air Conditioning.

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

#79

Post by ilamont »

GlickWick wrote: post #65
__MatrixMan__ wrote: post #15

I live in a colder climate where heat pumps are not popular. After talking with a number of HVAC people about this I was surprised to learn that despite being very similar to an AC system in principle, in practice converting an AC system into a heat pump system doesn't make economic sense--you end up just ripping one out and installing the other. I don't fully understand why this is the case, but I hope that there's…

I switched in New England when my freon system hit end of life. I wouldn’t recommend doing it beforehand, but as a replacement it’s been incredible. All the ductwork and infrastructure largely remained the same. Pulled out the furnace, evaporator coils, and compressor of course. It cools better than the old system, and the fact that it runs longer instead of in short bursts means it regulates humidity way better too.…

Fellow New Englander here. We had a 4 unit heat pump system installed a few years ago, replacing a bunch of window air conditioners. Not only is it a vast improvement over the window ACs in terms of ease of use, sound levels, comfort, and electricity use, it has become our default heat source in the winter as well, greatly reducing our natural gas bills.

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

#80

Post by rcme »

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).

Until the widespread use of heat pumps, AC was much more energy efficient than heating.
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