3 ms·
> At 10°f very few heat pumps can supply sufficient heat to keep even a decently insulated house properly heated - my guess is that many are using 2-3x less eff
by TulliusCicero 6y ago
> At 10°f very few heat pumps can supply sufficient heat to keep even a decently insulated house properly heated - my guess is that many are using 2-3x less efficient resistive heaters at night.
How is it possible for heating devices to be less efficient? Where does the waste energy go?
Normally, waste energy in devices powered by electricity means it's lost to heat, but here it would be lost to...?
- _whiteCaps_ 6y agohttps://www.sciencelearn.org.nz/resources/241-heat-pumps-and-energy-transfer https://www.sciencelearn.org.nz/resources/241-heat-pumps-and... Heat pumps use a small amount of energy to move thermal energy, but it's much more efficient than resistive heat. But if they can't move enough heat, they fall back to resistive heat to top it up.
- TulliusCicero 6y agoOhhhh, interesting. Right, that makes sense.
- joelwilliamson 6y agoThere's no waste heat with resistive heating, but heat pumps use electricity to move heat from outside to inside, and they can add more than 1J of heat using 1J of electricity.
- TFortunato 6y agoThe trick here is that with heat pumps, they aren't generating the heat, just moving it. As such, you can have, e.g. a 1 kW heat pump moving much more than 1 kW of heat. Wheras with a resistive heater, the best you can do is turn 1 kW of electric power into 1 kW of heat output.