Buying the Right Size Air Conditioner
- Don't use a contractor who wants to size your unit solely on your home's square footage. A contractor should spend time examining your house, measuring floors, ceilings and walls – including all the windows – and checking insulation in the attic, walls and crawlspaces. Some other factors that go into the cooling load formula include indoor and outdoor temperatures, number of occupants, shading, siding and roof. Contractors should calculate how much cooling a home needs according to guidelines such as the Air Conditioning Contractors of America's Manual J.
- Insist on getting a printout or copy of the cooling load calculations. These can be useful in comparing bids from contractors. If the calculations do not include at least all the items mentioned above, check with the contractor.
- Check for duct leaks – be sure ducts that are disconnected, crushed or too small for the system do not restrict air flow. Ideally, the contractor should use diagnostic equipment to find leaks and then fix them with quality duct sealants (not duct tape). In short, don't buy a larger air conditioner simply to cool your attic or crawlspace.
- Buy a high-efficiency unit – central air conditioners are rated by SEER, or Seasonal Energy Efficiency Ratio. If you are replacing an existing air conditioner, you must replace the whole unit, including the inside coil and often the blower fan, to achieve the rated efficiency.
- Install for ease of maintenance – make sure the inside coil can be reached for cleaning. The contractor may have to install an access panel, depending on the model. The coil should be cleaned every two years. The air filter should be located where it is easy to remove. Check it every month during the summer, and change or clean it whenever it is dirty.
- Place outside unit on north or east side of the house, out of direct sunlight. Leave plenty of room for free air flow on all sides, and at least four feet at the top. Keep the area free of debris and shrubbery.
For more energy-saving tips and money-saving projects, visit www.oge.com or call an OG&E specialist at 1-800-272-9741.