Seasonal air-conditioning maintenance

Weather heating up? Time to inspect and repair your home's air conditioning system! Follow these tips to keep cool all summer long.

• Before you go poking around your central A/C's system, turn the power off at its shutoff box (this is usually on an exterior wall near the system's outdoor unit). Some shutoffs are pulled out; others have a handle that you flip down or, less commonly, a fuse to remove.
• If there is no outdoor shutoff, cut power to the air conditioner at the main circuit breaker panel or fuse box.

• Making sure your air conditioner's filter is clean is probably the most important thing you can do to keep the system working at its peak. Check the filter once a month during the cooling season and replace it as needed.
• Remember that it's equally important to balance the airflow through your ductwork in summer and winter.
• Don't forget to change damper handles to summer settings at the start of the cooling season.

• The outdoor unit of your air-conditioning system needs to be free and clear to do its job. For maximum airflow, you'll need to maintain the area around it well. Keep at least a 60 centimetre (two-foot) radius clear of landscape plantings.
• When mowing the lawn, make sure grass clippings are directed away from the unit. To limit the amount of dust the fan draws into the unit, cover the ground around it with gravel, and add a layer of mulch to nearby flower beds.
• Fire ants, mice, and other critters love to set up housekeeping around the warmth of the condenser unit. Before screwing the top grille back on, make sure you evict any unwanted residents.

• Next, head indoors and turn your attention to the furnace's blower compartment. With the power turned off, open the blower compartment and vacuum it and the blower, and service the blower motor and belt.
• Check the condensation drain tube for sludge and algae buildup. To get rid of algae, carefully pour a solution of one part bleach to 16 parts water down a rigid drain tube (remove a flexible drain tube to flush it out). If possible, poke a wire into the drain port to clear it.
• It's important that you have your system professionally inspected and serviced every year in early spring.
• In addition, give it a thorough cleaning and tune-up at the beginning of each cooling season.

• Central air-conditioning systems consist of an outdoor unit containing a compressor and its motor, a condenser coil and a fan, and an indoor unit consisting of an evaporator coil usually located in the main supply duct (or plenum) above the furnace blower.
• Copper tubes — one insulated, the other bare — transfer refrigerant between the two units. In other words, the compressor pumps refrigerant back and forth between the evaporator coil, where the refrigerant absorbs heat from the air, thereby cooling it, and the condenser coil, where heat is released.