Heat pump cost 2-4 times lesser of energy to heat than non-heat pump heater, then why are non-heat pump heater still very common ?
(1) At home, boiler and water radiator is used.
(2) For district heating, central boiler is used.
Why aren't most these replace by heat pump?
For (2) the reason may be there is not enough heat source to pump from to support megawatts of power output.
Possible reasons for home: heat pump is driven by electricity and boiler cost lesser then electricity, then the cost difference is not that much.
I also heard in cold winter air conditioner won't work well as heat pump, is this true and is this a possible reason?