- cross-posted to:
- geography@mander.xyz
- technews@radiation.party
- cross-posted to:
- geography@mander.xyz
- technews@radiation.party
There is a discussion on Hacker News, but feel free to comment here as well.
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“you shouldn’t buy food because that means there’s less food available”
If people don’t have AC at all when temperatures are no longer livable, people will die. This is a dumb thing to guilt an entire population into.
It’s a good discussion in prioritizing:
- Urban design - reducing heat retaining materials and increasing greenery.
- Support for home efficiency improvements - more efficient homes require less AC.
- The type of AC we support - ground source heat pumps eliminate this problem (at the cost of increased up front cost that pays itself down).
I tried putting fire on the fire to stop it but it only made it worse
To answer the main physics question Yes obviously. It takes energy to move heat from one area to the other. Energy expended for work becomes heat. So the net heat of the system has to go up. The thermodynamic axiom
Is it significant? Yes, especially in developing areas where large populations are getting access to the energy and economy to support air conditioning.
Do we need to find better solutions? Absolutely
Having just spent some time in Hong Kong, a city that appears to be addicted to AC, I had wondered this myself. Shops completely open to the street would have air conditioners blasting. You almost had to wear a jumper inside many buildings because they were set so low. I went into shopping malls which had portable AC units because they has single glazed glass frontages which radiated heat.
This is the best summary I could come up with:
A study found that waste heat generated by a city’s worth of air conditioners during a heatwave can raise the outside temperature by more than 2 degrees Celsius.
As Europe faces more frequent and more intense heatwaves, you might have considered taking the plunge and buying an air conditioning unit.
It comes from a study published in 2020 that was based on a scenario in which air conditioners are used in all buildings of a city like Paris to maintain an interior temperature of 23 degrees Celsius during a heatwave.
Temperature increases due to air conditioning (AC) use “depend on the time of day and the characteristics of the heatwave, mainly its intensity”, according to the study.
They found that, after “Nine days of a heat wave similar to the one of 2003,” the systematic use of AC during that time would increase air temperature “by up to 2.4°C”.
And as cities are only likely to grow hotter as a result of climate change, that means that citizens are likely to demand more indoor air conditioning.
The original article contains 529 words, the summary contains 176 words. Saved 67%. I’m a bot and I’m open source!
Not just the AC. If we put a 20 amp load into a house with the washer and TV and lights and everything else, that energy has to Go SOMEWHERE, and eventually it pretty much all ends up as heat.
Air conditioners work by pumping heat outside.
Even without AC running, your house is still consuming electricity that eventually radiates to the outside.
There are orders of magnitude difference between what the air conditioning does, and what you’re referring to.
Did I accidentally post metrics that are incorrect? I certainly don’t remember that. Tens of watts times hundreds or millions of homes will still have a measurable effect even without AC. It’ll just be smaller and I don’t think anyone is going to argue that.
How dense do you think these homes are?
Just read the article
The measurable effect is from the heat pumps.
Heat pumps are exceptionally efficient
Right, but the area the heat was removed from gets colder. When looking at the city as a whole, the transferred heat cancels out. The only heat added to the system is the additional energy used to transfer the heat.
This article isn’t about the heat added to the entire planet
A lower energy alternative is to build homes with built-in heat sink loops. Basically it’s just a deep hole dug straight down that you loop a heat transfer fluid through and through a heat exchanger in the home. So if it is hot outside, you are pumping the heat in the home into the ground. The only cost is the pump which uses a very minor amount of electricity. If that becomes insufficient, then you can also use that fluid with a heat pump to increase the temperature differential. The key element here is allowing for a non-heat pump. Looping of the fluid through a heat exchanger that blows air through it.
This does require putting in the deep hole before the foundation or the rest of the house, but will allow for a significant decrease in the cost of heating or cooling the home.
If it is hotness that is the problem in that area and the ground is hot from geothermal energy then you should not build there unless you are able to use that heat and significant ways for cooking, hot water and making electricity to offset.