Selecting an energy-efficient room air conditioner is a good start, but using it wisely is also important.
In the example above, the annual energy cost was based on 615 hours of operation (the total running time of the unit's motor). The total operating hours of your room air conditioner may differ dramatically, depending on how you use the unit. Features such as timers and “fan-only” modes can help limit operating hours.
Here are some tips on how to save energy – and money.
Energy Efficiency Checklist
- Select the warmest thermostat setting that delivers an acceptable level of comfort. A setting of 25°C is recommended.
- Don't let heat build up all day and then, in an effort to cool quickly, switch your air conditioner to its maximum setting.
It's far more efficient to start the unit earlier in the day, letting the room cool gradually. A timer or programmable thermostat enables your air conditioner to cool and dehumidify slowly
- If the space is going to be unoccupied for more than four hours, set your thermostat to 28°C.
- Set the fan to operate continuously when you need air
movement to maintain comfortable conditions.
- Use the "fan-only" mode (if available) in the evening and early morning to draw cooler outside air into the house.
When I return home on a hot day, should I crank the
room air conditioner to its coldest setting to cool the
No. The temperature control is a thermostat, not a gas pedal. A room air conditioner takes heat and humidity out of the air at a preset rate; cranking the unit's thermostat won't make the room cool any faster and will waste energy in the long run. A timer leads to greater efficiency and comfort by switching on the unit only when it's needed. Use a timer to ensure you arrive home to a comfortable temperature.
- Close all doors leading to your air-conditioned space as much as possible to keep cool air in. Draw curtains and blinds to limit heat gain through windows.
- Shut closet doors to avoid cooling unused space. Close off fireplaces to prevent cool air from escaping up the chimney.
- Turn off lights and appliances when they aren't needed because they generate heat. In areas where lights are left on for long periods, replace incandescent bulbs with cooler-operating compact fluorescents.
- Use natural or fan-assisted ventilation to cool your house whenever outdoor temperatures and humidity levels drop.
- Read the owner's manual and follow the manufacturer's recommendations for installation, operation, cleaning and maintenance.
- Clean or change air filters regularly for optimal performance. A dirty air filter reduces airflow and operating efficiency and, in some cases, can damage a room air conditioner.
- Inspect the unit from inside and outside your home. From indoors, check vents to ensure airflow isn't blocked and that there is no frost build-up on the unit – both can damage the unit. From outdoors, ensure all vents are clean and free of debris, such as leaves. Consult your owner's manual for more detailed instructions.
- Before winter, remove, clean and store your air conditioner. Cover and seal the window opening for the unit to prevent air leaks. If it isn't possible to remove the unit, surround it with insulation from the inside, cover the insulation with polyethylene sheeting and seal it with duct tape.
- Consult the owner's manual or contact a service technician about the correct maintenance schedule for your unit. Some models require extra attention, such as regular lubrication of fan motors for noise-free operation.
- Service the unit whenever performance begins to deteriorate. A small loss of refrigerant can cause the unit to run more noisily, decrease operating efficiency and harm the environment. It's important to fix any leaks and recycle the unit's refrigerant whenever service is performed.
Supporting Energy Innovation Does Make a Difference
Beginning in the 1970s, new coil designs, more efficient compressors and better circulation systems led to a dramatic 15 percent drop per decade in the average energy consumption of room air conditioners (based on 750 hours of operation per year). This represents a shift in the average energy efficiency ratio, or EER, from 6.0 in the 1970s to nearly 10.5 today.
Today's energy-efficient units incorporate efficient rotary compressors and large evaporators and condensers with louvred fins and internally rifled tubes, as well as more efficient permanent split-capacitor (PSC) fans and slinger rings that deposit water collected from evaporators on to hot condensers. Models may soon have an EER of 13.
These units often offer advanced comfort features, such as noise reduction.
Components of a Room Air Conditioner
Two types of refrigerant – chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs), such as R-22 – are being phased out under the Montreal Protocol to reduce the use and release of ozone-depleting substances. Manufacturers of all new air conditioners sold in Canada and the United States must rely on refrigerants that meet increasingly strict environmental standards. In almost all cases, older room air conditioners can't be refilled with newer refrigerants.
For more information on the phase-out and alternatives to CFCs and HCFCs, visit Environment Canada's Stratospheric Ozone Web site at www.ec.gc.ca/ozone .