Proper installation is key to getting the most out of your central air conditioning system. Do it right and your A/C will be humming along at full capacity. Do it wrong and the efficiency of the system can be reduced by at least 30 percent, costing you more and possibly shortening the life of the equipment. In fact, Consumer Reports latest reliability survey shows a strong correlation between repairs and installation as well as some brands that are more repair prone than others.
In our survey of more than 40,000 readers who bought a central A/C system between 2005 and 2011, 10 percent reported repeated repairs during the first year after installation and 18 percent said their system broke down completely. Those who needed repairs often paid $150 or more for the fix.
Replacing a central air conditioning system, especially one that is more than 12 years old can result in substantial energy savings. And if you choose an Energy Star qualified model you can save even more--provided it's installed correctly. Some installation mistakes that'll cost you are improper refrigerant levels, air flow or equipment sizing, and duct leakage. To avoid that Energy Star recommends the following:
Size the unit properly. Installing the right size equipment for your home is essential to getting the best performance. Bigger isn't always better--a system actually operates best when each component is properly sized. Oversized equipment may cycle on and off more frequently, which can make the home less comfortable and shorten the equipment life. Make sure the contractor takes measurements of your home to determine the appropriate size for your air conditioner.
Seal ducts. Ducts circulate air from the central air conditioner or heat pump throughout the house. Damaged ducts or those with poor connections can leak the cold air, wasting energy and money. Sealing ducts can greatly improve the efficiency of your system.
Optimize air flow. To operate well, a cooling system needs to have the proper volume of air flow. If air flow is too high or too low , it may make the home less comfortable and increase utility bills.
Check the refrigerant. It's important for an air conditioner or heat pump to have the correct amount of refrigerant, or correct refrigerant charge. An improperly charged system may consume more energy and provide less dehumidification.
—Mary H.J. Farrell