The following hints and tips for homeowners, including any items that should be considered ahead of an installation, help ensure that they are choosing the right heat pump system for their home and that the equipment is being installed properly.

Building Efficiency

Building enclosure issues should be addressed before installing any new HVAC equipment. This includes but is not limited to issues with poor or inadequate insulation, leakiness of the building envelope, and duct leaks.

Addressing these issues before installing new heat pump equipment reduces a home's heating and cooling costs, improves comfort and heat pump performance, and reduces the required size of any new equipment. Homeowners should discuss any previous or planned changes to their homes with their heat pump contractors. For example, homeowners should mention improved attic insulation, new windows, changes to their homes' ventilation system, and control system improvements.

Correct Equipment Sizing

It is important to ensure that ASHP are properly sized for each application. Oversizing can lead to
excessive cycling, lower efficiency, and inadequate dehumidification during summer months. Room-by-room load calculations are preferable to other simplified approaches (e.g. block load calculations). However, room-by-room load calculations may not be necessary for many retrofit applications where existing heating systems will remain in place.

Getting the Right Heat Pump System (Including Supplementary Heating)

There are many different types of heat pump systems. The suitability of each system to different scenarios depends on a variety of factors, including the existing condition of the building, the configuration of the existing HVAC system, any other planned upgrades, occupancy requirements, and local weather conditions.

Some heat pump installations require a supplementary heating system; however, for most of BC, this need can be eliminated by selecting a heat pump that is sized for the home's design heating load. When supplementary heating systems are employed, ASHPs are often set to shut off at a particular temperature and supplementary heating system starts working beyond that point.

Conversely, ASHPs are sometimes designed to operate in conjunction with supplementary heating even at very cold temperatures since the ASHP may still be providing some useful heat. Supplementary heat can be supplied by any type of heating system. It may be incorporated into the heat pump or may be a separate system. Conventional ASHPs also require supplementary heating to prevent cold air from blowing in during defrost cycles.

Key ASHP Installation Criteria¹²

Heat pump contractors should include the following items in their quotations:

• Heat load calculation to size the system
• Thermal balance point temperature calculation, to optimize the design and control of supplementary heating system
• Outdoor unit installed above anticipated snow level with due regard to defrost water drainage, which may otherwise result in slip hazards and damage to walkways
• Line sets have all refrigeration lines insulated, and fully protected from UV
• All penetrations (i.e. floor, wall, ceiling) sealed
• A condensate pipe connected to a drain or pump (for central systems)

Many of the above items can be reviewed visually by homeowners, allowing them to verify the quality of a heat pump installation.

Benefits of Advanced Integrated Controls

Advanced integrated controls help maximize savings from ASHP systems by managing the interaction with a home's existing heating system.^f Control algorithms of advanced control systems minimize energy consumption and heating costs by prioritizing heat pump operation at appropriate times and ensuring that the supplementary heating system is operating during peak heating loads to ensure comfort.

Operation and Maintenance of your New Heat Pump

Operation: The energy savings from a heat pump are highly dependent on the operational behavior of a home's occupants. Below are some operational tips to maximize energy savings and ensure comfort:

• Try to keep indoor temperature settings steady and avoid frequently adjusting the thermostat.
• Avoid large temperature setbacks during colder periods since ASHPs can take a long time to recover without supplementary heat.
• Avoid turning heat pumps "on" and "off" to control the temperature, allow the thermostat to control the temperature instead.

Maintenance: Regular maintenance schedules are critical for reliable heat pump operation. Periodic maintenance can increase the service life of your equipment and will save you money on your utility bills. Below are some common maintenance tips:

• Clean filters as recommended by manufacturer and replace as necessary.
• Be sure to keep debris and snow away from outdoor units and ensure that there is sufficient airflow around them.
• Check on your system at least once every season to make sure there's no obvious damage to the outdoor pipe covering, dirt clogging the outdoor coil, or oil drips at or below the piping connections at the unit.
• There may be indicator lights or display icons on the controller or on the indoor unit itself, that can indicate fault conditions. Review your owner's manual to interpret any displays.
• Schedule professional service at the manufacturer's recommended interval (generally annually) or if you see any problems.
• Consider using ultraviolet (UV) light to prevent growth of mould and bacteria on the coil.

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^fWhere they are compatible. Older existing heating systems are more likely to have compatibility issues. Heating system is referred to as the economic balance point.