43 ms·

However, it's a lot easier to passively heat a house then to passively cool a house. We could easily upgrade building envelope standards, incorporate a heat pum

However, it's a lot easier to passively heat a house then to passively cool a house. We could easily upgrade building envelope standards, incorporate a heat pump, and reduce the heating-associated CO2 emissions to a fraction. If we did that, I think on net the Houston C02 emissions might be larger, since there really aren't equivalent ways to passively cool space.

post_break 6y ago
A lot of texas power grid is renewable however, which helps tilt the scales.
- saeranv 6y ago
  This works both ways! You can clean the grid in the the Northeast[1], and the clean energy would go a lot further to condition your (properly energy-retrofitted) houses then a house in Houston. [1] For example in Toronto, Ontario, the electric grid is fueled from hydro (and we get passive cooling from lake water). And yet, Toronto's urbanization is so intense (and still growing) so the city still needs to reduce the energy consumption of it's buildings to manage it's peak power consumption. And I would argue this still has a huge impact on CO2 emissions given the reduction of transportation emissions associated with high density areas.
  - frandroid 6y ago
    > hydro Okay, the power company is named Toronto Hydro, but it buys electricity from whatever is available on the grid, be it hydro, gas, nuclear (Darlington wasn't built to power Ottawa...), wind (hello Chatham farmland!) or solar.
    - saeranv 6y ago
      Ah I am humbled, I didn't know that.
kortilla 6y ago
There is no evidence this is really possible. Houston homes cooling a house 25 degrees will still be significantly less than maintaining a 100 degree difference in Minneapolis during a -30F snap. Don’t forget that there is significantly less daylight to work with in the winter for this “passive heating” too.
- saeranv 6y ago
  There's plenty of evidence. One example is Passive House standards (which can be applied to commercial contexts as well), which reduce heating loads by 90% using the methods I discussed. There's a lot of factors you're not accounting for: 1. Waste heat from lights, equipment, and people is constantly offsetting the heating energy, and contributing to cooling energy. There's so much equipment in office/commercial buildings, it's common to need air conditioning all through winter. 2. It's not just air temperature difference, it's also about solar radiation gain. Even in cold climate zones the peak load for cooling is significantly higher then the peak load for heating.
  - kortilla 6y ago
    Passive house standards don’t cut it. Reducing 90% doesn’t matter if many of those energy improvements also apply to cooling. > Waste heat from lights Use LEDs and this is irrelevant for a home. > people is constantly offsetting the heating energy Insignificant in the scheme of things. Humans can’t even keep themselves warm when holding still in 50F. > it's also about solar radiation gain. Do you realize how little sun cities in the north get during the winter? Conversely, solar electricity can conveniently capture plenty of electricity quite near the time it’s required in the South. Peak air con time is when there is solar radiation. Peak heating time is in the dead of night.
- mdorazio 6y ago
  Be careful here since it gets complicated between energy efficiency differences in heating vs. cooling, but also in greenhouse impact of the units themselves. For example, R410A used in modern A/C units is over 2000x more potent as a greenhouse gas than straight CO2, and A/C units leak quite frequently as they age. You also need to factor the greenhouse impact of the energy source of the local power grid during the season when heating/cooling are needed. It's hard to make a solid claim either way without looking at quite a bit of data.

post_break 6y ago

A lot of texas power grid is renewable however, which helps tilt the scales.

saeranv 6y ago
This works both ways! You can clean the grid in the the Northeast[1], and the clean energy would go a lot further to condition your (properly energy-retrofitted) houses then a house in Houston. [1] For example in Toronto, Ontario, the electric grid is fueled from hydro (and we get passive cooling from lake water). And yet, Toronto's urbanization is so intense (and still growing) so the city still needs to reduce the energy consumption of it's buildings to manage it's peak power consumption. And I would argue this still has a huge impact on CO2 emissions given the reduction of transportation emissions associated with high density areas.
- frandroid 6y ago
  > hydro Okay, the power company is named Toronto Hydro, but it buys electricity from whatever is available on the grid, be it hydro, gas, nuclear (Darlington wasn't built to power Ottawa...), wind (hello Chatham farmland!) or solar.
  - saeranv 6y ago
    Ah I am humbled, I didn't know that.

kortilla 6y ago

There is no evidence this is really possible. Houston homes cooling a house 25 degrees will still be significantly less than maintaining a 100 degree difference in Minneapolis during a -30F snap. Don’t forget that there is significantly less daylight to work with in the winter for this “passive heating” too.

saeranv 6y ago
There's plenty of evidence. One example is Passive House standards (which can be applied to commercial contexts as well), which reduce heating loads by 90% using the methods I discussed. There's a lot of factors you're not accounting for: 1. Waste heat from lights, equipment, and people is constantly offsetting the heating energy, and contributing to cooling energy. There's so much equipment in office/commercial buildings, it's common to need air conditioning all through winter. 2. It's not just air temperature difference, it's also about solar radiation gain. Even in cold climate zones the peak load for cooling is significantly higher then the peak load for heating.
- kortilla 6y ago
  Passive house standards don’t cut it. Reducing 90% doesn’t matter if many of those energy improvements also apply to cooling. > Waste heat from lights Use LEDs and this is irrelevant for a home. > people is constantly offsetting the heating energy Insignificant in the scheme of things. Humans can’t even keep themselves warm when holding still in 50F. > it's also about solar radiation gain. Do you realize how little sun cities in the north get during the winter? Conversely, solar electricity can conveniently capture plenty of electricity quite near the time it’s required in the South. Peak air con time is when there is solar radiation. Peak heating time is in the dead of night.
mdorazio 6y ago
Be careful here since it gets complicated between energy efficiency differences in heating vs. cooling, but also in greenhouse impact of the units themselves. For example, R410A used in modern A/C units is over 2000x more potent as a greenhouse gas than straight CO2, and A/C units leak quite frequently as they age. You also need to factor the greenhouse impact of the energy source of the local power grid during the season when heating/cooling are needed. It's hard to make a solid claim either way without looking at quite a bit of data.