5 ms·

It’s much easier to heat something than to cool it. You can build a fire without any technology at all, but you can’t do anything about unsurvivable heat withou

by goerz 3y ago

It’s much easier to heat something than to cool it. You can build a fire without any technology at all, but you can’t do anything about unsurvivable heat without a working power grid.

solardev 3y ago
Not dismissing your overall point (it's certainly easier to just combust something for heat) but it's not strictly true that you can't cool without electricity. There are techniques both modern and ancient that can help, though sadly most structures aren't built this way: https://en.wikipedia.org/wiki/Passive_cooling?wprov=sfla1 https://en.wikipedia.org/wiki/Passive_cooling?wprov=sfla1 Where it gets really problematic is places that used to have a moderate climate (vs always having been hot) so the people and structures have no adaptations for the sudden extreme heat.
- goerz 3y ago
  Yes, you can absolutely (and we will have to) mitigate hot temperatures with building design, but only up to the point where you have wet bulb temperatures >35C over several days. There are heavily populated areas that are in real danger of having something like that happening, and this is what that would look like: https://www.orbitbooks.net/orbit-excerpts/the-ministry-for-the-future/ https://www.orbitbooks.net/orbit-excerpts/the-ministry-for-t...
wongarsu 3y ago
Heating is much easier, but in the right conditions you can still do a lot without power. - The simplest is just having thermal mass to average day and night temperature. As long as the night is cold enough you can just stay in a brick or clay building with thick walls, preferably painted white. - If you want to get a bit more advanced, you can use evaporative cooling, like Persian Yakhchāls [1]. - If you go high-tech, certain paints can cool surfaces down by a couple degrees (by radiating heat at frequencies that don't get absorbed by the atmosphere, thus breaking the equilibrium between heat absorption and heat emission). Of course there is a point where those fail. Evaporative cooling is dependent on a low wet-bulb temperature and fails quickly in humid climate. Thermal mass needs temperature differences. Paints only buy you a couple degrees. In contrast an AC can be scaled to much higher temperatures. 1: https://en.wikipedia.org/wiki/Yakhch%C4%81l https://en.wikipedia.org/wiki/Yakhch%C4%81l
- goerz 3y ago
  Right, but we're talking about being extremely close to the point where these will fail due to unsurvivable wet bulb temperatures
  - frumper 3y ago
    Your comment is 5 parents deep and not one mentions wet bulb until you just now. The wet bulb temp of Death Valley is in the 70s or 80s. Hardly unsurvivable wet bulb temperatures.
    - falcolas 3y ago
      Death Valley is also a bit of an outlier in it's dryness. Of course, that's what also makes it a desert. It wouldn't take much humidity to turn those temperatures into wet-bulb of 100+ - fatal to humans. Expanding the area of this level of heat a couple of hundred miles in any direction would probably be enough.
    - ttfkam 3y ago
      https://www.washingtonpost.com/news/capital-weather-gang/wp/2015/07/30/iran-city-hits-suffocating-heat-index-of-154-degrees-near-world-record/ https://www.washingtonpost.com/news/capital-weather-gang/wp/...
      - frumper 3y ago
        > Right, but we're talking about being extremely close to the point where these will fail due to unsurvivable wet bulb temperatures I'm not sure who we is, and it wasn't clear anyone was talking about wet bulb temperatures. It's a comment on an article about Death Valley. At this point, you're just responding with things completely unrelated(behind paywalls).
        ttfkam 3y ago
        Because Death Valley is our local bellwether for where heat extremes are headed. The issues of soaring temperatures will affect far more than Death Valley, especially where the humidity is much higher.
empthought 3y ago
Sure you can; you can tunnel a few feet underground.
- goerz 3y ago
  Not if the air that you need to breathe has a wet bulb temperature >35C
  - empthought 3y ago
    Not gonna happen in Death Valley
ProfessorLayton 3y ago
It takes a lot less energy to cool down a dwelling than it does to heat it, due to the delta between the inside/outside being a lot lower when it's too hot vs when it's too cold (Which can easily go into the negatives). Sure, it takes no technology to start a fire in an emergency, but that can't be done at a mass scale for non-emergency habitability without making the problem worse in the long run. AC can run from the very same energy that's heating up a dwelling, and power grids will need to be adjusted to incorporate more clean power sources.
- ttfkam 3y ago
  > It takes a lot less energy to cool down a dwelling ...only in low humidity. Also, PV solar efficiency drops quite a bit as the temperature goes up. Carnot efficiency also drops noticeably as your cold sink, the ambient environment around you, heats up. Are you going to provide AC to all the livestock and crops as well? Because they're kind of important in the long run too.
  - ProfessorLayton 3y ago
    Running AC lowers the dwelling humidity, so I'm not sure what you're referring to. Lower PV efficiency means some margin/overcapacity will be needed, not free but also not an insurmountable problem either. There's more energy being cast upon earth every single day than we'll ever need, and the same cannot be said for hydrocarbons. Temperature control for livestock applies to cold climates too, so kind of a moot point to mention one and not the other. Running AC in hot areas does not necessitate making climate change worse. Heat pumps are very efficient in cold climates too, but it doesn't change the fact that much more energy is required due to the temperature deltas being dealt with.
gambiting 3y ago
And yet a LOT more people die every year due to cold than due to heat.

by goerz 3y ago

It’s much easier to heat something than to cool it. You can build a fire without any technology at all, but you can’t do anything about unsurvivable heat without a working power grid.

solardev 3y ago

Not dismissing your overall point (it's certainly easier to just combust something for heat) but it's not strictly true that you can't cool without electricity. There are techniques both modern and ancient that can help, though sadly most structures aren't built this way: https://en.wikipedia.org/wiki/Passive_cooling?wprov=sfla1 https://en.wikipedia.org/wiki/Passive_cooling?wprov=sfla1 Where it gets really problematic is places that used to have a moderate climate (vs always having been hot) so the people and structures have no adaptations for the sudden extreme heat.

goerz 3y ago
Yes, you can absolutely (and we will have to) mitigate hot temperatures with building design, but only up to the point where you have wet bulb temperatures >35C over several days. There are heavily populated areas that are in real danger of having something like that happening, and this is what that would look like: https://www.orbitbooks.net/orbit-excerpts/the-ministry-for-the-future/ https://www.orbitbooks.net/orbit-excerpts/the-ministry-for-t...

wongarsu 3y ago

Heating is much easier, but in the right conditions you can still do a lot without power. - The simplest is just having thermal mass to average day and night temperature. As long as the night is cold enough you can just stay in a brick or clay building with thick walls, preferably painted white. - If you want to get a bit more advanced, you can use evaporative cooling, like Persian Yakhchāls [1]. - If you go high-tech, certain paints can cool surfaces down by a couple degrees (by radiating heat at frequencies that don't get absorbed by the atmosphere, thus breaking the equilibrium between heat absorption and heat emission). Of course there is a point where those fail. Evaporative cooling is dependent on a low wet-bulb temperature and fails quickly in humid climate. Thermal mass needs temperature differences. Paints only buy you a couple degrees. In contrast an AC can be scaled to much higher temperatures. 1: https://en.wikipedia.org/wiki/Yakhch%C4%81l https://en.wikipedia.org/wiki/Yakhch%C4%81l

goerz 3y ago
Right, but we're talking about being extremely close to the point where these will fail due to unsurvivable wet bulb temperatures
- frumper 3y ago
  Your comment is 5 parents deep and not one mentions wet bulb until you just now. The wet bulb temp of Death Valley is in the 70s or 80s. Hardly unsurvivable wet bulb temperatures.
  - falcolas 3y ago
    Death Valley is also a bit of an outlier in it's dryness. Of course, that's what also makes it a desert. It wouldn't take much humidity to turn those temperatures into wet-bulb of 100+ - fatal to humans. Expanding the area of this level of heat a couple of hundred miles in any direction would probably be enough.
  - ttfkam 3y ago
    https://www.washingtonpost.com/news/capital-weather-gang/wp/2015/07/30/iran-city-hits-suffocating-heat-index-of-154-degrees-near-world-record/ https://www.washingtonpost.com/news/capital-weather-gang/wp/...
    - frumper 3y ago
      > Right, but we're talking about being extremely close to the point where these will fail due to unsurvivable wet bulb temperatures I'm not sure who we is, and it wasn't clear anyone was talking about wet bulb temperatures. It's a comment on an article about Death Valley. At this point, you're just responding with things completely unrelated(behind paywalls).
      - ttfkam 3y ago
        Because Death Valley is our local bellwether for where heat extremes are headed. The issues of soaring temperatures will affect far more than Death Valley, especially where the humidity is much higher.

empthought 3y ago

Sure you can; you can tunnel a few feet underground.

goerz 3y ago
Not if the air that you need to breathe has a wet bulb temperature >35C
- empthought 3y ago
  Not gonna happen in Death Valley

ProfessorLayton 3y ago

It takes a lot less energy to cool down a dwelling than it does to heat it, due to the delta between the inside/outside being a lot lower when it's too hot vs when it's too cold (Which can easily go into the negatives). Sure, it takes no technology to start a fire in an emergency, but that can't be done at a mass scale for non-emergency habitability without making the problem worse in the long run. AC can run from the very same energy that's heating up a dwelling, and power grids will need to be adjusted to incorporate more clean power sources.

ttfkam 3y ago
> It takes a lot less energy to cool down a dwelling ...only in low humidity. Also, PV solar efficiency drops quite a bit as the temperature goes up. Carnot efficiency also drops noticeably as your cold sink, the ambient environment around you, heats up. Are you going to provide AC to all the livestock and crops as well? Because they're kind of important in the long run too.
- ProfessorLayton 3y ago
  Running AC lowers the dwelling humidity, so I'm not sure what you're referring to. Lower PV efficiency means some margin/overcapacity will be needed, not free but also not an insurmountable problem either. There's more energy being cast upon earth every single day than we'll ever need, and the same cannot be said for hydrocarbons. Temperature control for livestock applies to cold climates too, so kind of a moot point to mention one and not the other. Running AC in hot areas does not necessitate making climate change worse. Heat pumps are very efficient in cold climates too, but it doesn't change the fact that much more energy is required due to the temperature deltas being dealt with.

gambiting 3y ago

And yet a LOT more people die every year due to cold than due to heat.