Tips for Buying a Central Air Conditioner

• The type and size of air conditioner you need depends on your climate and cooling loads. Evaporative coolers are practical in hot, arid regions such as the southwest. For other regions, compressor-driven air-conditioning systems are the only choice.
• When you are shopping for a central air conditioner, look for a SEER rating higher than 12.0.
• If you already have a forced-air heating system, you may be able to tie an air conditioner into existing ducts, depending on their size and your home's relative heating and cooling loads. A good HVAC contractor can do the calculations for you.
• Proper sizing and installation are key elements in determining air conditioner efficiency. Too large a unit will not adequately remove humidity. Too small a unit will not be able to maintain a comfortable temperature on the hottest days. Improper unit location, lack of duct insulation, improper duct sealing, and incorrect refrigerant charge can greatly diminish efficiency.
• When buying a central air conditioner, look for a system with a fan-only switch so you can use the unit for nighttime ventilation to substantially reduce air-conditioning costs; a filter check light to remind you to check the filter after a predetermined number of operating hours; and an automatic-delay fan switch to turn off the fan a few minutes after the compressor turns off.
• Look for a unit with quiet operation.
• If you need or want to replace your existing air conditioner's outdoor (compressor) unit, make sure the indoor (blower coil) unit is compatible with the new outdoor unit. A highly efficient outdoor unit will not achieve its rated efficiency if paired with an older blower coil.

Content Provided By the DOE