4 ms·

This effect is temporary. Otherwise one could run their AC once for a few minutes and then it'd be cold inside your home for the rest of the year until you turn

This effect is temporary. Otherwise one could run their AC once for a few minutes and then it'd be cold inside your home for the rest of the year until you turn up heating. In reality equilibrium is restored quickly (and the thermal mass we're cooling/heating here is insignificant anyhow).

jackyinger 4mo ago
That heat goes out into the world, it doesn’t just disappear
- ericd 4mo ago
  Eventually radiates out into space ;-) It doesn’t disappear, but we don’t need to care much about infrared passing Alpha Centauri.
  - thayne 4mo ago
    Except we have an lot of greenhouse gases that are really good at reflecting that infrared back down to earth.
  - rippeltippel 4mo ago
    Eventually yes, perhaps. But first heat gets trapped in Earth's atmosphere, because pollution and greenhouse gases make it hard for it to dissipate into space. It's called global warming, and no - it's not a hoax.
    - ericd 4mo ago
      Heh yes, I’m aware, thanks.
- ssl-3 4mo ago
  The house being cooled by aircon is within the same world as everything else is. This doesn't mean that there's zero heat added locally (as many seem fond of suggesting): The compressors and circulation blowers and fans don't run for free, and every Joule of electricity they consume is ultimately converted to a Joule of heat in a process that wouldn't occur in the absence of aircon. That's not zero. But in very broad strokes, it's not very significant. It's somewhat akin to running a refrigerator inside of a kitchen. With aircon, the refrigerator is the size a whole house. That certainly sounds huge, and it is huge. But that refrigerated building is inside of a room that is the size of the Earth's atmosphere, which is very obviously vast in ways that kitchens simply are not. It doesn't really matter. Millions of homes with aircon don't mean much when the atmosphere is millions of times bigger than they are.
thayne 4mo ago
The process of moving heat from your house outside also creates excess heat, because no AC system is completely efficient (and it can't be because of the second law of thermodynamics).
- subscribed 4mo ago
  Heat pumps have efficiency 300-400% at the moment, meaning they pump out MUCH more than they generate .
  - Noaidi 3mo ago
    That is some Trump math. How can you be more than 100% efficient?
    - subscribed 3mo ago
      It's okay to be ignorant, but it's not okay to be aggressive about that at the same time. Heat pump uses electricity. It does, however, transfer more energy than it's using. Magic of science! That page should be simple enough for the start: https://qualityhomeaircare.com/heat-pump-efficiency/ https://qualityhomeaircare.com/heat-pump-efficiency/ > Heat pumps convert energy to heat more efficiently than combustion-based systems, potentially delivering 300-400% efficiency compared to the 80-98% efficiency of the best furnaces and boilers. > This fundamental advantage stems from the fact that heat pumps move heat rather than generate it through combustion or resistance.
  - subscribed 3mo ago
    s/generate/use/ Sadly can't edit the original comment anymore.
  - thayne 3mo ago
    Yes, but it still generates some heat. 300% means the ratio of the heat energy transfered to the energy consumed is 3. Perfect efficiency would be infinite COP.

jackyinger 4mo ago

That heat goes out into the world, it doesn’t just disappear

ericd 4mo ago
Eventually radiates out into space ;-) It doesn’t disappear, but we don’t need to care much about infrared passing Alpha Centauri.
- thayne 4mo ago
  Except we have an lot of greenhouse gases that are really good at reflecting that infrared back down to earth.
- rippeltippel 4mo ago
  Eventually yes, perhaps. But first heat gets trapped in Earth's atmosphere, because pollution and greenhouse gases make it hard for it to dissipate into space. It's called global warming, and no - it's not a hoax.
  - ericd 4mo ago
    Heh yes, I’m aware, thanks.
ssl-3 4mo ago
The house being cooled by aircon is within the same world as everything else is. This doesn't mean that there's zero heat added locally (as many seem fond of suggesting): The compressors and circulation blowers and fans don't run for free, and every Joule of electricity they consume is ultimately converted to a Joule of heat in a process that wouldn't occur in the absence of aircon. That's not zero. But in very broad strokes, it's not very significant. It's somewhat akin to running a refrigerator inside of a kitchen. With aircon, the refrigerator is the size a whole house. That certainly sounds huge, and it is huge. But that refrigerated building is inside of a room that is the size of the Earth's atmosphere, which is very obviously vast in ways that kitchens simply are not. It doesn't really matter. Millions of homes with aircon don't mean much when the atmosphere is millions of times bigger than they are.

thayne 4mo ago

The process of moving heat from your house outside also creates excess heat, because no AC system is completely efficient (and it can't be because of the second law of thermodynamics).

subscribed 4mo ago
Heat pumps have efficiency 300-400% at the moment, meaning they pump out MUCH more than they generate .
- Noaidi 3mo ago
  That is some Trump math. How can you be more than 100% efficient?
  - subscribed 3mo ago
    It's okay to be ignorant, but it's not okay to be aggressive about that at the same time. Heat pump uses electricity. It does, however, transfer more energy than it's using. Magic of science! That page should be simple enough for the start: https://qualityhomeaircare.com/heat-pump-efficiency/ https://qualityhomeaircare.com/heat-pump-efficiency/ > Heat pumps convert energy to heat more efficiently than combustion-based systems, potentially delivering 300-400% efficiency compared to the 80-98% efficiency of the best furnaces and boilers. > This fundamental advantage stems from the fact that heat pumps move heat rather than generate it through combustion or resistance.
- subscribed 3mo ago
  s/generate/use/ Sadly can't edit the original comment anymore.
- thayne 3mo ago
  Yes, but it still generates some heat. 300% means the ratio of the heat energy transfered to the energy consumed is 3. Perfect efficiency would be infinite COP.