Many people buy or use air-conditioners without understanding their design, components and operating principles. Proper sizing, selection, insulation, maintenance and operation are key to cost-effective use and lower overall costs.

Day to day activities

Field Inspection Check List, including a regular cleaning of the system

• Duct insulation
• Duct leaks
• Ducts connections
• Fans
• Condensate drain
• Coils

Recommendations, advice and tips

Before installing any air-conditioning system :

• Radiant or solar heat gain through windows can cause occupant discomfort and increased air conditioning costs. The more glass the building has, especially on east, west, and south-facing exposures, the more important window shading is to improve comfort and reduce air conditioning bills. Please note :
  • Interior shading devices can block up to 65% of the sun’s heat that would be otherwise transferred through the window
  • Exterior shading can block up to 95% of the sun’s heat
  • Any shading device that can be removed during the heating season is desirable over a permanent device, particularly on southern exposures. South-facing windows can be a good source of "free" heating in winter. The best type of shading will depend on site-specific factors and requirements

When opting for an air-conditioning system :

• Obtain information regarding cooling/heating output ; energy efficiency ratio ; energy consumption ; and energy efficiency class, before buying an air conditioner
• Install outdoor units out of direct sunlight
• Consider the installation of a heat pump. High-efficiency heat pumps also dehumidify better than standard central air conditioners, resulting in less energy usage and more cooling comfort in summer months :
• The most common type of heat pump is the air-source heat pump, which transfers heat between your house and the outside air. If you heat with electricity, a heat pump can trim the amount of electricity you use for heating by as much as 30%–40%. However, the efficiency of most electricity-driven air-source heat pumps drops dramatically at low temperatures, generally making them unsuitable for cold climates.
• Higher efficiencies are achieved with geothermal (ground-source or water-source) heat pumps, which transfer heat between your building and the ground or a nearby water source. Although they cost more to install, geothermal heat pumps have low operating costs because they take advantage of relatively constant ground or water temperatures

To improve the performance of an existing system :

• Enable cooling equipment only if sun blinds are activated but temperatures remain above 26°C.
• Clean indoor and outdoor coils before warm weather starts : A dirty coil causes more energy consumption and decreases the life of the equipment
• Thermostats should be checked, cleaned and calibrated periodically
• Insulate supply ducts in unconditioned space
• Seal leaks and connections with mastic, metal tape or with an aerosol-based sealant. (Poorly performing ducts can leak conditioned air and reduce a system’s efficiency by as much as 20%.)
• Check air conditioning filters every month. A filter clogged with dust and lint reduces the unit’s cooling ability ; include a new filter as part of any duct system improvements
• Repair or replace damaged, disconnected, or undersized ducts
• Use high-efficiency electric motors