Before beginning any installation work, contractors should consider the following factors that have significant influence on the viability of air-source heat pumps:
Relevant codes, standards, and regulations in the local jurisdiction should be reviewed to ensure that all required health and safety considerations are properly addressed. Refer to CSA Standards C2733.5-11 "Installation of air- source heat pumps and air conditioners", the BC Building Code (e.g. Division B, Part 6: Heating, Ventilating and air Conditioning, Part 7: Plumbing Services, Part 10: Energy Efficiency, etc.), and the Technical Safety BC for further information on health and safety regulations related to heat pump installations. WorkSafe BC regulated issues, such as asbestos abatement, should also be reviewed since they can prevent a heat pump installation from occurring if they are not properly mitigated.
Installation contractors should assess the existing heating and cooling system type, location, and layout. It is also important to consider occupancy, usage patterns, and the local climate. Furthermore, consideration should be given towards other equipment that may be dependent on the existing system and might affect the viability of the ASHP installation. In particular, some combustion appliances may be dependent on the existing heating system for venting. This can include hot water tanks and other equipment related to the home HVAC system. In these cases, venting changes may be required.
Contractors should evaluate whether supplementary heating is required based on local design conditions, heat load calculations, and/or to improve comfort during defrost cycles with some systems. Based on design conditions of the Lower Mainland and Vancouver Island, properly sized conventional ASHPs can meet the heating requirements on the coldest day.
Similarly, properly sized cold climate ASHPs can meet the heating requirement of homes located in the Southern Interior without any supplementary heating, while supplementary heating may be required for homes located in the Northern Interior. In cases where homeowners request a supplementary heating system even though it is not required, existing heating systems should be considered first. It is also recommended that supplementary heating systems be sized for emergency heating where incremental cost are small (e.g. additional electric resistance heating in homes not requiring panel upgrades).
Contractors should assess the availability of applicable utility rebates, tax credits, and other financial support available for homeowners in their jurisdiction.