4 ms·

Its easier, but it isn't more energy efficient, at least not for winters. Average deltaT is smaller when cooling 35 to 25, compared to heating -10 to 20, say.

by brnt 2y ago

Its easier, but it isn't more energy efficient, at least not for winters. Average deltaT is smaller when cooling 35 to 25, compared to heating -10 to 20, say. A problem in cities is that aircos increase outdoor temps, on top of heat from pavement, cars, etc.

bluefirebrand 2y ago
There is no way heating isn't more energy efficient than cooling Heat is even a side effect of cooling, heat is a side effect of basically everything
- rimunroe 2y ago
  You’re correct that it is more energy efficient to heat, but the US spends much more energy heating buildings compared to cooling them. As the person you’re responding to pointed out, the difference between cold days and comfortable temperatures is usually much, much higher than the difference between hot days and comfortable temperatures for most people.
  - bluefirebrand 2y ago
    That's reasonable Then again the difference between lethal cold temperatures and comfortable temperatures is also much much bigger than lethal hot temperatures and comfortable temperatures too. EG humans can be pretty comfortable between 32F and 80-90F. The upper limit is pretty much 110F, so only a 20F difference. There's not really any sort of clothing short of some kind of spacesuit with a personal cooling device that can make those temperatures survivable. Humans can tolerate ridiculously cold temperatures with adequate clothing layers. With clothing you can buy at Walmart you can be pretty comfortable at -40F. With specialized equipment there's basically no limit to how cold the surroundings can be Not so much with ridiculously hot. Being too hot is just a more complex problem to solve
  - quesera 2y ago
    > the US spends much more energy heating buildings compared to cooling them I was curious about the stats here: The latest numbers I can find indicate that the annual US 50-state heating-to-comfort requirement is about 2.5x the cooling-to-comfort requirement. Measured in BTUs. However: a) These numbers do not account for HVAC energy efficiency (much higher for heating than cooling -- maybe ~90% heat, ~50% cool, so that 2.5x would be closer to 1.5x today) b) Due to warming trends, these numbers have been changing. Was ~3x in 1990, trendlines look like they might converge by the end of the century. With efficiency considered, convergence in about 25 years. Some obvious unaccounted factors: a) Changes in HVAC fuel or efficiency mix, e.g. heat pumps b) Changes in climate trends c) Migration patterns (more people headed to TX/AZ than AK)
- brnt 2y ago
  Have a look at how heat pumps work. The difference between cooling and heating is just which end you point inside or outside. For efficiency it only matter what the delta-T with the outside environment is. Since that is typically lower when cooling than when heating, it is therefore cheaper. Just look at your power bill.
  - bluefirebrand 2y ago
    > Have a look at how heat pumps work Most buildings where I live don't have heat pumps

by brnt 2y ago

bluefirebrand 2y ago

There is no way heating isn't more energy efficient than cooling Heat is even a side effect of cooling, heat is a side effect of basically everything

rimunroe 2y ago
You’re correct that it is more energy efficient to heat, but the US spends much more energy heating buildings compared to cooling them. As the person you’re responding to pointed out, the difference between cold days and comfortable temperatures is usually much, much higher than the difference between hot days and comfortable temperatures for most people.
- bluefirebrand 2y ago
  That's reasonable Then again the difference between lethal cold temperatures and comfortable temperatures is also much much bigger than lethal hot temperatures and comfortable temperatures too. EG humans can be pretty comfortable between 32F and 80-90F. The upper limit is pretty much 110F, so only a 20F difference. There's not really any sort of clothing short of some kind of spacesuit with a personal cooling device that can make those temperatures survivable. Humans can tolerate ridiculously cold temperatures with adequate clothing layers. With clothing you can buy at Walmart you can be pretty comfortable at -40F. With specialized equipment there's basically no limit to how cold the surroundings can be Not so much with ridiculously hot. Being too hot is just a more complex problem to solve
- quesera 2y ago
  > the US spends much more energy heating buildings compared to cooling them I was curious about the stats here: The latest numbers I can find indicate that the annual US 50-state heating-to-comfort requirement is about 2.5x the cooling-to-comfort requirement. Measured in BTUs. However: a) These numbers do not account for HVAC energy efficiency (much higher for heating than cooling -- maybe ~90% heat, ~50% cool, so that 2.5x would be closer to 1.5x today) b) Due to warming trends, these numbers have been changing. Was ~3x in 1990, trendlines look like they might converge by the end of the century. With efficiency considered, convergence in about 25 years. Some obvious unaccounted factors: a) Changes in HVAC fuel or efficiency mix, e.g. heat pumps b) Changes in climate trends c) Migration patterns (more people headed to TX/AZ than AK)
brnt 2y ago
Have a look at how heat pumps work. The difference between cooling and heating is just which end you point inside or outside. For efficiency it only matter what the delta-T with the outside environment is. Since that is typically lower when cooling than when heating, it is therefore cheaper. Just look at your power bill.
- bluefirebrand 2y ago
  > Have a look at how heat pumps work Most buildings where I live don't have heat pumps