Heat Pumps 101

A closer look at one of the best ways to save AND reduce emissions

Heating accounts for about 60% of the energy used in Canadian homes and buildings.  It’s expensive, and it can be a huge source of emissions too, especially if that energy comes from natural gas or coal-fired electricity.

Heat pumps to the rescue!  They’re super efficient – and current incentive programs make them really affordable too.  Plus – the International Energy Agency estimates that widespread adoption by 2030 could reduce global greenhouse gas emissions by at least 500 million tonnes a year – that’s equal to the annual emissions of all cars in Europe today!

So here, in point form, is a short primer about heat pumps.

• How they work: it’s helpful to imagine buildings with heat pumps as inside-out refrigerators.  Whereas a fridge is a box where the inside gets cooled and heat is expelled out through the coils on the back of the box, a building with a heat pump is a box where the outside gets cooled, and heat is expelled into interior spaces. 
• There are two types: air-source heat pumps extract heat from outside air by cooling it several degrees.  They then release that heat into interior spaces.  Ground-source heat pumps (also called geothermal heat pumps) use wells or a system of underground coils to extract heat from underground in the same way; and then release that heat into interior spaces.  Some also produce hot water.
• Air-source heat pumps can be ductless or ducted: ductless heat pumps (also known as mini-splits) have their indoor units mounted on a wall and release heat directly into the room in which they are located.  Ducted heat pumps (also called central heat pumps) distribute heat throughout a building via a system of ducts.
• Super efficient: whereas baseboard heaters produce just one unit of heat for every unit of electricity used, heat pumps can produce up to five units of heat for every unit of electricity used.  That explains why they can be such money-savers!  (The fine print: keep reading for more on cold temperature performance of air source heat pumps.)
• Operating range: today’s air-source heat pumps work well to temperatures as low as -25 degrees C; some even work to as low as -30 degrees C.  However, it’s important to note that their efficiency does drop the colder it gets (because the colder air is, the harder it is to extract heat from it).  Ground-source heat pumps are consistently very efficient all year round because temperatures underground are very stable.
• Advantages of air-source heat pumps: less expensive to install than ground-source; ductless in particular are easy and inexpensive retrofits for homes and buildings with baseboard heaters.
• Advantages of ground-source heat pumps: very efficient year-round; able to provide domestic hot water as well for further savings.
• Some maintenance required: all heat pumps require basic maintenance like regular cleaning of filters, and perhaps annual servicing by a qualified contractor.
• Cooling, a double-edged sword: most heat pumps have the ability to provide cooling as well as heating.  The downside: summer air conditioning may offset some of winter heat savings.
• Incentives: check out generous federal incentives under the Canada Greener Homes Initiative, the federal Oil to Heat Pump Affordability Program and for your province (for New Brunswick, here).

For a deeper dive, check out this guide from Natural Resources Canada, or this explanation complete with cool graphics!