Saskatchewan's Green Directory Helping Saskatchewan choose a better environment

Conventional air conditioning is an energy-intensive process, which in an ideal world would be avoided in virtually any application in Saskatchewan through good building energy design. Occupants can often help to render it unnecessary by means of internal or external shading, and enhanced summer ventilation. However, there will be situations -- typically a result of building design constraints or concentrations of heat-generating equipment (such as computers) -- where it is required.

What to look for

"Efficiency"

Our only criteria at present relate to the electrical energy required per unit of heat extracted. In North America, air conditioning efficacy is measured by the Energy Efficiency Ratio (EER) and the Seasonal Energy Efficiency Ratio (SEER). (European manufacturers will quote the average or seasonal cooling coefficient of performance, or COP_c. To convert the COP_c to EER or SEER, multiply by 3.415 -- provided that it is cited for Canadian climate/temperature conditions).

Air source or ground source?

The units listed here are technically air source heat pumps used for a cooling load. If you need air conditioning, you may find a ground-source heat pump can better meet your requirements: these units have better SEERs. Their higher installation cost may, however, generally only be justified if they are also used for winter heating -- see our section on ground source heat pumps.

Proper sizing

Make sure the capacity of your air conditioner matches the maximum load for your building. Ideally you should have this calculated by a professional building services engineer or building physicist.

Working fluid

Ask your supplier what working fluid ("refrigerant") their units use.
Following the phase-out of ozone-depleting working fluids (CFCs and HCFCs), modern air conditioners (in common with fridges) now typically use hydrofluorocarbons (HFCs) instead. The most common working fluids are now R23, R134a and R152a. These have no effect on the ozone layer, but they are potent greenhouse gases. Hence there is an inevitable contribution to global warming resulting from slow leaks from the system, but this is a relatively small effect. A more important concern is what happens at the end of the airconditioner's life - it is important that the unit be retired and the working fluid securely recovered before significant leaks become a serious possibility. You may therefore want to ask your supplier about arrangements for end-of-life disposal. A better option - though one currently restricted by lack of availability - would be to opt for a working fluid which is non-ozone-depleting and has a low global warming potential. (At present, the principal contender is R290.)

Government grants

Grants are available for more efficient air conditioning systems from two government programmes: EnerGuide for Houses (Saskatchewan) and ecoEnergy Retrofit (federal).

Criteria