Air-source heat pumps (ASHPs) can often help reduce the energy consumption, operating costs, and environmental impacts associated with heating and cooling homes; this is especially true with homes that are heated by electric baseboards, fuel oil, or propane. Heat pumps can also help improve occupant comfort in many situations. However, poor design and installation practices, such as improper sizing and selection and poor sealing of building envelope penetrations, may reduce these potential benefits.

Various studies have found significant reductions in the overall efficiency of heat pump systems as a result of installation issues^{1, 2}. Poor installation practices may also reinforce misperceptions that ASHPs are not well suited to Canadian winters, creating a barrier towards the increased adoption of heat pumps by both homeowner and installers.

A recent study on ASHP installation practices in BC indicated that only 32% of the studied ASHP installations were well-matched with the heating requirement of the homes they were installed in, while the remaining units were either oversized or undersized³. The study also found that the savings from the ASHP systems was lower than would be expected in most of the sites. This guide, which is primarily focused on experienced installers of heat pump systems, attempts to address these issues by providing best practice guidelines for the design and installation of common types of residential ASHPs.

Following installation best practices can benefit installation contractors through referrals, increase sales, reduced callbacks, and improved customer comfort and satisfaction. Contractors can also use this guide as a tool to educate homeowners on the advantages of installation best practices. Additional advantages for contractors, homeowners, and the broader public are summarized below.