Before the cooling season

A cooling check-up looks at the parts that move heat out of your home. ENERGY STAR advises having a contractor do check-ups every year before each season. Dirty coils reduce the system's ability to cool your home and make it run longer, which raises energy costs and shortens the equipment's life. Too much or too little refrigerant makes the system less efficient, raising energy costs and shortening the equipment's life. Cleaning and adjusting the blower keeps the airflow right, and airflow problems can cut a system's efficiency by up to 15 percent.

The electrical side is checked too. The technician tightens electrical connections and measures voltage and current on motors, because faulty connections can make the system run unsafely and shorten the life of major parts. The controls and the starting cycle are checked so the system starts, runs and shuts off properly. A system that starts the summer in good order is less likely to surprise you in a heat wave.

Source: ENERGY STAR

An air conditioner pulls water out of the air as it cools, and that water has to drain away. ENERGY STAR says to check the condensate drain on your central air conditioner, furnace or heat pump in cooling mode, because a plugged drain can cause water damage in the house and affect indoor humidity. The EPA says to keep drip pans clean and drain lines clear and flowing properly. Drain pans can become reservoirs for mold and bacteria if they are not installed and maintained properly, so they should be checked routinely. If pans do not drain, or are not cleaned often, they may let water into the system and contaminate the ducts.

The coils need to stay clean as well. Dirt on coils gets in the way of moving heat, which lowers efficiency and raises costs. A dirty indoor coil reduces airflow, will eventually cause the coil to freeze over, and may damage the compressor. The EPA describes yearly maintenance as regular cleaning of drain pans and heating and cooling coils, regular filter changes and a yearly inspection of heating equipment.

Source: ENERGY STAR · U.S. EPA · U.S. Department of Energy

The outdoor unit gets rid of the heat taken from your home, so it needs open air around it. Clear anything that blocks the outdoor unit's airflow throughout the year. Keeping units clear of dust, snow, leaves and other debris is vital for the best performance. For ductless heat pumps, the clearances in installation manuals are minimums and are often not enough room for maintenance, cleaning and removing debris. After winter, look around the unit for leaves, branches or anything stacked against it.

Source: U.S. Department of Energy · ENERGY STAR · Northwest Energy Efficiency Alliance

Refrigerant is the fluid that carries heat from inside your home to the outside, and handling it is regulated. Anyone who could be expected to open the refrigerant circuit during maintenance, service or repair, and so release refrigerant, must be certified. Under the Clean Air Act, the EPA forbids knowingly venting refrigerants, including R-22 and R-410A, while maintaining, servicing, repairing or disposing of air conditioners. Homeowners should work with dealers whose service technicians are EPA-certified to handle refrigerants.

A system that needs refrigerant added may have a leak. Major leaks rarely develop in units that were installed properly and maintained regularly. If your air conditioner leaks, the EPA says to ask your technician to find and repair the leak instead of topping it off. So adding refrigerant is never a do-it-yourself spring task.

Source: U.S. EPA

If you have a ductless mini-split, spring is a good time to look at its indoor units. Many ductless systems have washable mesh filters that catch few fine particles but keep airflow open. A typical maker's recommendation is to clean these mesh filters every two weeks, by washing or vacuuming them. ENERGY STAR says heat pump filters should be cleaned when they look dirty or when the filter light says so.

Dust and moisture can also build up inside. Most wall-mounted units are built in a way that lets moisture collect on the blower wheel, the fan, in cooling mode, which makes more dust stick to it. Dust and moisture together can lead to fungal growth, a real concern for the air in your home. To see whether a deep cleaning is needed, look closely at the blower wheel: dust and mold on it and on the air vanes mean it is time. Deep cleaning is generally not a do-it-yourself job, because indoor units are hard to take apart and need special equipment and cleaners.

Source: U.S. Department of Energy · ENERGY STAR

Window and through-the-wall units need a little care when they go back in. Make sure the unit is level so its drainage works. A poorly installed room air conditioner leaks as much air as a 6-square-inch hole, which raises energy costs and makes your home less comfortable. ENERGY STAR's product criteria describe a filter reminder that tells you when the filter needs checking, cleaning or replacing, to keep the unit running efficiently.

Power matters too. Limit the use of extension cords, especially for room air conditioners. Air conditioners are among the seasonal appliances that can put added strain on a home's wiring and can cause a fire. At the end of the cooling season, take the unit out if you can, or use a cover sized for it over the winter.

Source: ENERGY STAR · U.S. Consumer Product Safety Commission