Pocket Change has done a pretty deep dive on this and found that an Air Source Heat Pump (ASHP) is the best choice out there for replacing your gas furnace. An ASHP is both an air conditioner and a furnace in one. There are hybrid (gas/electric) ASHPs and fully electric ones. Both options will make a giant impact in GHG reductions from home heating.
ASHP technology has been around forever and has been commonly used in milder climates for decades but tweaks and improvements in the last 10 years have finally made it an option in Canada. It is 3 x more efficient than electric or gas furnaces because it doesn’t generate heat, it just moves it around. In the fall/winter/spring it sucks the heat from the air outside (there’s a surprising amount of heat in winter air!) and pumps it indoors and in the summer, it sucks the heat from inside your house and pumps it outside.
A fully electric ASHP would take your home off gas heating completely and is a fantastic choice for hard core shrinking of your carbon footprint but it will set you back 15 to 22k depending on whether you need to upgrade your electricity panel to accommodate the increased load or not. This option would reduce your green house gas (GHG)emissions from home heating by 90 to 95%. Your heating costs would remain about the same.
The hybrid option is much cheaper. In the hybrid scenario, the ASHP connects to your gas furnace and heats your home down to around -3 per to - 5 at which point the gas furnace takes over. The combined cost, after tax and install, of a mid range high efficiency furnace and ASHP is around 10k.
There are only about 20 days a year that fall below -3 to -5 so you will be decarbonizing a great deal of your home heating. Your heating costs remain about the same and your greenhouse gas emissions are reduced by about 35 to 60% - still pretty amazing! And, as the carbon tax increases year over year – you’ll be able to pocket the savings from the rebate because of your big reductions in gas consumption.
Another great thing about the hybrid option is that you can choose to set the “change over point” (the temp at which the ASHP switches to gas heating) to -2 or even 0 and and significantly reduce your home heating costs – although you will also limit GHG reductions as well.
There are fantastic rebates on both versions from the new Greener Homes Grant.
This article from Thompson Architecture is a terrific resource for all things ASHP, as well providing various roadmaps to reducing your GHG’s through HVAC options.
This webinar on ASHPs from the City of TO is also great and easy to understand.
If you want to connect with someone in person to chat about ASHPs – you can reach Paul Dowsett at [email protected].
