Choosing room-sized air conditioners

By The Old House Web
It might surprise you to know that buying a bigger room air-conditioning unit won't necessarily make you feel more comfortable during the hot summer months.

In fact, a room air conditioner that's too big for the area it is supposed to cool will perform less efficiently and less effectively than a smaller, properly sized unit.

This is because room units work better if they run for relatively long periods of time than if they are continually, switching off and on. Longer run times allow air conditioners to maintain a more constant room temperature.

Sizing is equally important for central air-conditioning systems, which need to be sized by professionals. If you have a central air system in your home, set the fan to shut off at the same time as the cooling unit (compressor). In other words, don't use the system's central fan to provide circulation, but instead use circulating fans in individual rooms.

The shopping guide that follows will help you find the right size unit for your needs.

The ENERGY STAR label is the government's seal of approval. It was created by the U.S. Department of Energy and the U.S. Environmental Protection Agency. These agencies set the criteria to help shoppers for large and small home appliances identify the most energy-efficient products on the market.

ENERGY STAR-labeled appliances exceed existing federal efficiency standards, typically, by 13% to 20%, and as much as 110% for some appliances.

Customers can be assured that the appliance being purchased is a high-performance product which will reduce the operating cost of that appliance or product every month during the course of its lifetime.

Central Air Conditioners
  • Look for the EnergyGuide label with a SEER (Seasonal Energy Efficiency Rating) for central air conditioners.
  • The ENERGY STAR(r) minimum efficiency level is 12 SEER. ENERGY STAR(r) central air conditioners exceed federal standards by at least 20%.
  • Air conditioners that bear the ENERGY STAR(r) label may be twice as efficient as some existing systems. Contact a professional for advice on sizing a central air system.
Room Air Conditioners
  • Look for the EnergyGuide label with an EER (Energy Efficiency Rating) for room air conditioners. The higher the EER, the more efficient the unit is. ENERGY STAR(r) units are among the most energy-efficient products.
  • Two major decisions should guide your purchase. Buy a correctly sized unit. Buy an energy-efficient unit. If the room is very sunny, increase capacity by 10%. If the unit is for a kitchen, increase the capacity by 4,000 Btu per hour.
  • Be sure to buy a correctly sized unit!

Source of Story: The U.S. Department of Energy: Tips on Saving Energy and Money at Home

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