Air Conditioners (Central)
What To Look For
If your current air conditioner is more than eight years old, it's time for a new one. Over the life of the product, the amount you'll save in energy bills will more than likely exceed the cost of the new unit. An added bonus: for every kilowatt hour (kWh) of electricity you save, you prevent the release of 1.34 lbs. of carbon dioxide (CO2) from your power plant. Over a summer season, this could result in a CO2 reduction of several hundred pounds and energy savings of about $65, when compared to an older model.
The following are basic criteria to use when choosing a new unit:
BTUs
The cooling capacity of an air conditioner is measured in British thermal units per hour (Btu/hr). To find the best BTUs needed to cool your home, multiply the square footage of the space by 10 and then add 4,000. A room that is 500 sq. ft. would require at least 9,000 BTUs/hr: (500 x 10) + 4,000 = 9,000. Make sure you get the right size model for your needs. Choosing an air conditioner that is either too large or too small creates an unnecessary energy drain.
When determining your BTU needs, consider your local climate (both heat and humidity), window placement and the average heat level of the space directly above the room you want to cool, whether it's your roof or a neighbor's apartment. For a more accurate assessment, use the free sizing worksheet on the Association of Home Appliance Manufacturers' web site, www.cooloff.org/sub_cool.html, where you can input various factors to calculate your BTU needs. Or see the BTU equivalency chart at www.energystar.gov.
SEER (Maximum)
Central air conditioner efficiency is rated by its Seasonal Energy-Efficiency Ratio (SEER). The federal SEER requirement is 13 or above, and Energy Star requires SEERs of 14 or above. The units listed in our Product Comparisons chart are series of appliances, designed to outfit homes of varying sizes. The SEERs listed represent those of the most efficient units in each series.
Energy Star Rating
The Environmental Protection Agency's "Energy Star" ratings indicate that an appliance is at least 10 percent more energy-efficient than the minimum federal standards.
ACEEE Rated
The nonprofit American Council for an Energy-Efficient Economy (ACEEE) recommends central air conditioners that represent manufacturers' most efficient models. For maximum energy savings, ACEEE recommends purchasing units with a SEER of at least 14.5.
