- cross-posted to:
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- cross-posted to:
- [email protected]
Sales are growing so quickly that some installers wonder whether heat pumps could even wipe out the demand for new air conditioners in a few years and put a significant dent in the number of natural gas furnaces.
Just to share some climate change context, as of 2020, natural gas usage by buildings (mostly for heating) accounted for 54% of community-wide emissions in Toronto. Transportation only accounted for 33%, so reducing our use of natural gas for heating is something Canada needs majorly to focus on if we don’t want to burn.
To me, it’s absolutely crazy that AC units are even still marketed. An air conditioner is just a heat pump that only work in one direction (cooling). All that is needed to allow it to work for both heating and cooling is one extra valve. If you’re going to install a heat pump (in the form of an air conditioner) and a furnace anyway, you might as well let the heat pump provide heating as well. That way, your furnace is only required on the coldest nights. For most of the year, the heat pump is sufficient.
With the caveat that at lower outdoor temperatures (think below about -20C), heat pumps become increasingly ineffective at heating up indoor spaces.
For places that reach those temperatures in winter (most of the prairies and northern Ontario) you also need supplemental heating of some sort.
Well, everywhere in Canada outside of maybe Vancouver does dip deep below -20 once in a while. But for the “Quebec City to Windsor corridor” (which is where about half of Canada lives eg GTA) you theoretically should be able to get away with some electric space heaters as a backup heating source. They’d be expensive to run but it would likely only be for a few days per year.
“Pay for more electricity” might not work very well, if everybody in a region uses resistive heat at the same time. I’m not sure what the solution is… maybe an overprovisioned power grid, cheaper battery tech, or tanks of renewable backup fuel like dimethyl ether?
Local power storage.
If you’re home had a battery bank, it could slow-charge pretty much all the time, then help pick up large on-demand loads like heating/cooling (air, water, food, etc).
Then the power grid would see a relatively steady load from each home with the batteries smoothing out spikes in usage.
Add on local generation like solar or wind to further reduce that load on the grid.
Heat pumps often have the option of a heater strip that lets it work at those temperatures.
At what point is city wide infrastructure the answer?
Especially for hot water. Is it worth ripping up the roads and putting in hot water pipes or are we at the point in “electrify everything” that it’s actually cheaper to have individual appliances for everything.
I can’t help put think with hot water most is used in morning or at night. Seems like a huge storage tank that is filled at night and at peak solar is beneficial for the grid.
Hot water continuously radiates it’s heat into the environment around it. City wide hot water infrastructure would be hugely inefficient and impractical as that water would constantly have to circulate to and from homes to be re-heated and re-circulated.
Literally heating massive quantities of water; just to pump it out into essentially a field (of pipes), wait for it to cool, then pump it back and do it again.
Without that recirculation to keep hotwater immediately available at each home/tap; you’d be waiting hours for all the cooled off water to flush out of the pipes and be replaced with hot water, wasting all that water while you wait. (kinda like waiting on a typical hotwater tank, but x100)
Electric hot water on demand combined with green sources of electricity should be the goal.
Lots of countries have city hot water. It’s a simple concept. I don’t there there is that much heat wasted covering that many people in such a small area.
I just wondered about the economics. I think most of the current ones use waste heat from electricity generation
I live in one of those countries. Heat waste is a big problem, you can sometimes see where the heat pipes are because of melted snow above them. Many houses are poorly insulated as well and lose even more energy.
Central heating, as we call it, is infamous for being rather inflexible and often expensive. I used to pay up to 20% of my salary for heat during colder winters. I now live in an apartment building with its own soil-ethanol geothermal heating and my heating bills are 10% of what it used to be.
Many heating plants still burn oil products to make heat, and those are often expensive. There has been a big push to switch to locally produced biomass to cut costs.