Wrong symbol in the title:
º = ordinal indicator
° = degree
Improving air conditioner efficiency could reduce worldwide temps
91–100 of 349 posts
Re: Improving air conditioner efficiency could reduce worldwide temps
#92American air conditioners running at full power, chilling the interior and dripping on the sidewalk below on a hot day always deeply trouble me. Maybe it's my european view on things, but for contrast here in Munich we aren't just building out a city-wide heat network, but we also have a cold network! Cold river water flows through the pipe network that traverses the city and large office building can get connected t…
AC saves lives. I think concrete and blacktop everywhere is way worse.
Re: Improving air conditioner efficiency could reduce worldwide temps
#93Earlier quoted context omitted.
It's been mentioned elsewhere in this thread, but if you run your refrigerant loop through the ground instead of cooling it using the hot ambient air, you can absolutely achieve that improvement in efficiency. The concept is described here: https://energy.gov/energysaver/geothermal-heat-pumps The amount of efficiency increase you get depends on the ground temp, which varies by latitude, but I've seen 70% reductions i…
The challenge for these is the cost. First, you either have to drill wells that are ~500 feet deep or lay coils of tubing under your yard (if you have one) below the frost line. Doing either is expensive, though the wells are much more so. The downside of the cheaper option (the coils under yard) is that earth shifts, and the coils will too. I've had two separate friends install these (usually 4-6 separate coils) onl…
Sure, it's cost, but that's solvable.
1. Drilling the wells is not actually that expensive depending where you are.
For me, 3 300 ft wells, bored, piped, and grouted, was about 5k.
2. The units can be gotten for that price with install.
You need to take into account the fact that they are significantly more efficient at both heating, and cooling, and hot water, over their lifetime.
(also, their specs and submittal data usually have real numbers, giving you mappings from incoming water temperature/etc to EER, not BS numbers like most outdoor air A/C units)
They would also be cheaper if they sold more of them :)
3. The units are much easier to keep working, and pretty much never die. They are made much better than the average heat pump. As for your coils, yeah, doing horizontal loops is not a good plan in most cases, though cheaper.
With the 30% federal tax credit that used to exist, a state tax credit, etc, i paid 10k all told.
I made that back in 2 years (the electric bill in the winter went from 600 a month to 100. Yes, the heat pump was functioning properly)
In areas of the country where well drilling is more common, it's a great option. I wouldn't do it in say, the bay area.
But note: none of the wells have to be that expensive to drill, and in fact, when done during new construction, they are often really cheap.
It's just a matter of, in various parts of the country, limited set of people have well drilling rigs because it's not that common. So part of the cost may be "having some guys drive a well drilling rig 5-6 hours to come handle it"
Re: Improving air conditioner efficiency could reduce worldwide temps
#94American air conditioners running at full power, chilling the interior and dripping on the sidewalk below on a hot day always deeply trouble me. Maybe it's my european view on things, but for contrast here in Munich we aren't just building out a city-wide heat network, but we also have a cold network! Cold river water flows through the pipe network that traverses the city and large office building can get connected t…
Berlin doesn't nearly get as hot as the United States. Try sitting inside a house in Mobile, AL in July without air conditioner and see how long you last. Using your water example, what about the deserts in the US that don't have a nearby water source to cool everything. Europe is much cooler in comparison to the US.
I agree with most of what you've said, but I'd also argue that having large groups living out in the desert is such an absurd configuration for humans that it presupposes an indifference for any sort of sustainability.
Re: Improving air conditioner efficiency could reduce worldwide temps
#95American air conditioners running at full power, chilling the interior and dripping on the sidewalk below on a hot day always deeply trouble me. Maybe it's my european view on things, but for contrast here in Munich we aren't just building out a city-wide heat network, but we also have a cold network! Cold river water flows through the pipe network that traverses the city and large office building can get connected t…
http://www.ugra.org/pdfs/SurfaceWaterTemp.pdf
Random Texas river temperature ranges from 55º (winter) to 85º (summer). The world is a big place with lots of climate variety. :-)
Re: Improving air conditioner efficiency could reduce worldwide temps
#96American air conditioners running at full power, chilling the interior and dripping on the sidewalk below on a hot day always deeply trouble me. Maybe it's my european view on things, but for contrast here in Munich we aren't just building out a city-wide heat network, but we also have a cold network! Cold river water flows through the pipe network that traverses the city and large office building can get connected t…
Berlin doesn't nearly get as hot as the United States. Try sitting inside a house in Mobile, AL in July without air conditioner and see how long you last. Using your water example, what about the deserts in the US that don't have a nearby water source to cool everything. Europe is much cooler in comparison to the US.
My bedroom in Tampa, FL reaches 90F at night without air conditioning. There is no way I could live without AC here.
Re: Improving air conditioner efficiency could reduce worldwide temps
#97Earlier quoted context omitted.
It's been mentioned elsewhere in this thread, but if you run your refrigerant loop through the ground instead of cooling it using the hot ambient air, you can absolutely achieve that improvement in efficiency. The concept is described here: https://energy.gov/energysaver/geothermal-heat-pumps The amount of efficiency increase you get depends on the ground temp, which varies by latitude, but I've seen 70% reductions i…
The challenge for these is the cost. First, you either have to drill wells that are ~500 feet deep or lay coils of tubing under your yard (if you have one) below the frost line. Doing either is expensive, though the wells are much more so. The downside of the cheaper option (the coils under yard) is that earth shifts, and the coils will too. I've had two separate friends install these (usually 4-6 separate coils) onl…
Thanks for the practical counterpoint. They are definitely pricier and the installation is more complex, but they do pay for themselves over time and should add to the value of the home.
I'm surprised about the earth movement ruining coils. The installations I've seen pictures of show coils with pretty large radii (maybe 18"), I'd think the earth would have to move a lot to do that, and if it's doing that I'd worry about the foundation. Were these small coils? Is the surface really close to the water table?
Re: Improving air conditioner efficiency could reduce worldwide temps
#98One thing missing from this article is demand response: "It matters, researchers say, because cooling has a direct relationship with the building of coal-fired power plants to meet peak demand. If more air-conditioners are humming in more homes and offices, then more capacity will be required to meet the demand. So 1.6 billion new air-conditioners by 2050 means thousands of new power plants will have to come on line…
> "So 1.6 billion new air-conditioners by 2050 means thousands of new power plants will have to come on line to support them."
Or not, where California has brought enough solar power online to the point that during peak times it has to pay to offload power to other states because some natural gas operators can't (won't?) shutdown...
Re: Improving air conditioner efficiency could reduce worldwide temps
#99American air conditioners running at full power, chilling the interior and dripping on the sidewalk below on a hot day always deeply trouble me. Maybe it's my european view on things, but for contrast here in Munich we aren't just building out a city-wide heat network, but we also have a cold network! Cold river water flows through the pipe network that traverses the city and large office building can get connected t…
And warming up the rivers won't lead to any problems regarding their ecosystem?
No. The vast majority of the heat is removed from the water by a processing plant before it gets reinjected into the stream. The temperature difference is negligible.
Re: Improving air conditioner efficiency could reduce worldwide temps
#100Earlier quoted context omitted.
It's been mentioned elsewhere in this thread, but if you run your refrigerant loop through the ground instead of cooling it using the hot ambient air, you can absolutely achieve that improvement in efficiency. The concept is described here: https://energy.gov/energysaver/geothermal-heat-pumps The amount of efficiency increase you get depends on the ground temp, which varies by latitude, but I've seen 70% reductions i…
The challenge for these is the cost. First, you either have to drill wells that are ~500 feet deep or lay coils of tubing under your yard (if you have one) below the frost line. Doing either is expensive, though the wells are much more so. The downside of the cheaper option (the coils under yard) is that earth shifts, and the coils will too. I've had two separate friends install these (usually 4-6 separate coils) onl…
It's a regional thing; they seem to be common here in Michigan. It seems to be proportional to the degree of temperature swings? They're not great if the ground and air are always warm or always cold.
We have winter lows below 10F/-10C and summer highs above 85F/30C. But the ground temperature is a relatively uniform 50F - useful for both heating (less important, because natural gas is cheap and efficient) and cooling. It's not so useful when the average temp is above your desired room temp.