7 ms·

Cold weather heat pump technology is consistently getting better, but I also think people underestimate how many heating days are above freezing even in cold ar

Cold weather heat pump technology is consistently getting better, but I also think people underestimate how many heating days are above freezing even in cold areas and how much of the US and other places is mild enough in the winter for heat pumps to be fairly efficient nearly every day during the winter (especially if you look at population rather than land area). If you look at a place like Minneapolis, which is normally considered a pretty cold US metro area, you do have a few months where the average temp is below zero. But you also have several more months where the temperature is cold enough to turn on the heat but well above freezing, where a heat pump is dramatically more efficient. When picking a heating system, it makes sense to consider comparative efficiency over the entire year, not just performance during the worst conditions in the middle of winter. Even in a city like Minneapolis, it's not obvious that heat pumps are less competitive over the entire year, even if their performance in January probably isn't fantastic. I also think the practical geographic area extends further than people think. New York City definitely isn't the south, but per some random Googling, it doesn't appear to have any months where the average temperature is below freezing. Even Boston only has 2 months that barely drop below freezing. Most of the US northeast (definitely the mid-atlantic) by population arguably also falls into the range where heat pumps make sense.

FredPret 4y ago
But then you need two systems - heatpump for most of the year, and natural gas for the cold days when you would die without it. At least in Canada I’d need to know that my system can handle a week of -30 or -40C in my city. Some places are even colder, for longer at a time.
- tialaramex 4y ago
  No, electricity is versatile, you can just make electricity into heat on that day when it's too cold for your heat pump. Resistive heating is not exciting > 100% efficiency technology, but it works and if you live somewhere that realistically gets too cold to run the heat pump that's what you add, not a whole gas burning system.
  - FredPret 4y ago
    I don’t know why I didn’t think of that. I guess the only remaining concern is that winter storms cause both cold weather and trees falling onto powerlines. The latter is rare though
    - tialaramex 4y ago
      Right, but (a) most modern gas fired heating actually requires mains electricity to function properly, so if you are blacked out your heating probably is disabled and... (b) even if the heating does work, a modern home is a pretty miserable place with no electricity, unless you know power will be back soon (hours or sooner) you should probably set out for a communal safe respite centre where everybody can work together to stay warm, feed and care for each other until the emergency is resolved. There are people who genuinely live in the middle of nowhere, on an otherwise uninhabited island as caretaker, deep in the forest manning a fire watch tower, Antarctic research base, that sort o thing, who do need have more options, because if they run out of options they're dead. If you're in that situation you still don't necessarily want gas heating though, a fossil fuel powered generator might make a lot of sense, maybe even more than one, because again electricity is so versatile.
      - mindslight 4y ago
        A snow storm plus power outage makes me want to bed down, not flee. The idea of leaving your house for a community center during a power outage is odd to me on several axes (pipes freezing, digging out your car, driving on half-plowed roads), especially in the hyper-individualist US (do these centers even exist?) It's much simpler to obtain and fuel a small generator to power meta loads like thermostats/circulators/blowers than a large generator that supplies the thermal load. Fully committing to a heat pump as your only heating would likely involve a large gas generator fed by municipal gas or at least a large buried propane tank (for capacity and temperature). The straightforward backup heat answer is wood. It's easy to obtain and store, and the primary drawback of it requiring labor and attention isn't a big deal during an outage. Although if you don't do it regularly and make sure your stove is in good order, lighting a fire during an emergency situation might not be the best idea.
- dd36 4y ago
  I can’t reply to telaramex directly but backup electric resistance is exactly how my heat pump hot water works.

FredPret 4y ago

But then you need two systems - heatpump for most of the year, and natural gas for the cold days when you would die without it. At least in Canada I’d need to know that my system can handle a week of -30 or -40C in my city. Some places are even colder, for longer at a time.

tialaramex 4y ago
No, electricity is versatile, you can just make electricity into heat on that day when it's too cold for your heat pump. Resistive heating is not exciting > 100% efficiency technology, but it works and if you live somewhere that realistically gets too cold to run the heat pump that's what you add, not a whole gas burning system.
- FredPret 4y ago
  I don’t know why I didn’t think of that. I guess the only remaining concern is that winter storms cause both cold weather and trees falling onto powerlines. The latter is rare though
  - tialaramex 4y ago
    Right, but (a) most modern gas fired heating actually requires mains electricity to function properly, so if you are blacked out your heating probably is disabled and... (b) even if the heating does work, a modern home is a pretty miserable place with no electricity, unless you know power will be back soon (hours or sooner) you should probably set out for a communal safe respite centre where everybody can work together to stay warm, feed and care for each other until the emergency is resolved. There are people who genuinely live in the middle of nowhere, on an otherwise uninhabited island as caretaker, deep in the forest manning a fire watch tower, Antarctic research base, that sort o thing, who do need have more options, because if they run out of options they're dead. If you're in that situation you still don't necessarily want gas heating though, a fossil fuel powered generator might make a lot of sense, maybe even more than one, because again electricity is so versatile.
    - mindslight 4y ago
      A snow storm plus power outage makes me want to bed down, not flee. The idea of leaving your house for a community center during a power outage is odd to me on several axes (pipes freezing, digging out your car, driving on half-plowed roads), especially in the hyper-individualist US (do these centers even exist?) It's much simpler to obtain and fuel a small generator to power meta loads like thermostats/circulators/blowers than a large generator that supplies the thermal load. Fully committing to a heat pump as your only heating would likely involve a large gas generator fed by municipal gas or at least a large buried propane tank (for capacity and temperature). The straightforward backup heat answer is wood. It's easy to obtain and store, and the primary drawback of it requiring labor and attention isn't a big deal during an outage. Although if you don't do it regularly and make sure your stove is in good order, lighting a fire during an emergency situation might not be the best idea.
dd36 4y ago
I can’t reply to telaramex directly but backup electric resistance is exactly how my heat pump hot water works.