HEAT PUMP vs FURNACE/AC 2

[08201950]

In a cold country like Canada, do heat pumps work in the winter?
Do heat pumps have any advantage over conventional furnace and air-conditioning systems (for houses).
A company in Maine manufactures so-called "low-temperature" heat pumps - does anybody have any experience with this line of products?

 

[ChrisConley]

Canada's a big place. Any particular region you're concerned with? NWT, Yukon, Maritimes, Prairies, Mountains? Coast? I'll assume you're talking about air-source heat pumps.

The issue with an air-source heat pump is that the colder it is outside, the less capacity is available for heating. Which means, you need a larger and larger heat pump (with electric heating coil).

Likely, this will result in oversizing (with much cycling) in the summer.

A secondary issue is the efficiency of the heat pump (COP). For the sake of argument we'll say that an air-source heat pump is 3x as efficient as a gas-furnace (I would argue this is only true in mild temperatures as the efficiency also drops at very low temperatures). The cost of electricity as a heating source ranges from 1.5X to 4X the cost of natural gas, which frequently will eliminate any cost benefits.

A final issue is that I have never seen an air-source heat pump capable of operating down to my lowest design temperature, I imagine other cold countries would have this issue.

 

[KiwiMace]

Often the 'low temperature' feature is an electric heating coil that kicks in when the outdoor temps get too low for the heat pump.