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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

#61

Post by afavour »

mathgeek wrote: post #57
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.

As a thought experiment, the same logic can be applied to any region where lack of shelter or heating would make human life unsustainable.

If you completely ignore the concept of energy efficiency, sure.

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

#62

Post by __MatrixMan__ »

elil17 wrote: post #41
__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…

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 pumps (and from thermostats, etc, which are not ready to handle the conversion).

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

#63

Post by londons_explore »

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…

It raises the question of if we should deploy 'emergency coolers' - perhaps single-use barrels of some chemical that gets cold when a pull-tab is pulled. To be a workable solution, it needs to be more reliable/cheaper/more effective than just a regular gasoline generator powering a regular aircon unit.

After a flood/hurricane/nuclear strike, they would provide enough coolness to keep people alive for a few days.

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

#64

Post by davidmurdoch »

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.

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

#65

Post by GlickWick »

__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.

For heat we did go dual fuel, which means the backup heating element uses gas, since we already had the line. This works really well in a cold snap where temps drop well below freezing.

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

#66

Post by pkulak »

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?

Relying on a coat for survival is very different from relying on an HVAC system. One has no moving parts, requires no external inputs, and is routinely handed out for free to those who can’t afford them.

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

#67

Post by chrsig »

davidmurdoch wrote: post #56

Being a Florida native, seeing an article titled "Heat Pumps [are] the Future of A/Cs" feels like it should have a ` [1973]` tacked on to the end of it. A heat pump is pretty much the only thing we use here, we just use them in reverse. Literally. Most residential units have a "reversing valve" that must be held open by a constant 24V in order to cool the air - the default mode is heating -- which is so smart to have…

My electric furnace needed to be urgently replaced in the beginning of the winter, I'm quite happy that my new heat pump would default to heat...Half of the year :)

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

#68

Post by GlickWick »

nightski wrote: post #26
__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…

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.

They make heat pumps with backup gas systems now.

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

#69

Post by davidmurdoch »

ptmcc wrote: post #32
lhoff wrote: post #21

Earlier quoted context omitted.

[flagged]

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.

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

#70

Post by itzworm »

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.
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