abcs.gif (6627 bytes)

Summer’s almost here, which means the number of people buying air conditioners is going to rise as surely as the mercury. Cooling a room can be tricky, though. If your air conditioner is too big, you’re throwing away money on electric bills; too small, and you’re not cooling the room effectively.
According to Jim Rogers. Panasonic’s national marketing manager for Major Appliances, choosing the right size air conditioner is as important as selecting a reliable brand.
“The function of an air conditioner is to cool a room as efficiently and as inexpensively as possible,” Rogers says. “This means finding a unit specifically suited for the room or area to be cooled, and that’s where the numbers come in.”
The key number for air conditioners is the BTU, or British Thermal Unit, which expresses the amount of heat needed to raise the temperature of one pound of water 1 degree Fahrenheit.
The ability of an air conditioner to cool is expressed in BTU’s per hour, or the quantity of heat the air conditioner can remove from a room in one hour. This number normally ranges from 4,700 to 29,000, with most household air conditioners falling between 5,000 and 14,000.
If the air conditioner has too few BTUs/hour for its area, it won’t cool effectively. If it has too many BTUs/hour for the room, the space will be overcooled and energy will be wasted. So how do you determine the right number of BTUs needed in an air conditioner?
According to Rogers, several factors come into play. Most important is the size of the room or area to be cooled, in square feet. This figure is obtained by multiplying the length and width of the room, in feet.
As a general rule, he says, 5,000 BTUs are needed to cool a room that’s 100-150 square feet. Figure on 1,000 additional BTUs for every 50 extra square feet, cooling 10,000 BTUs for 450 square feet. For areas measuring 450-550 square feet, cooling capacity should be 12,000 BTUs, and for 550-700 square feet, 14,000 BTUs are required.
Geographic location is another factor to consider. Residents of New England and the Northwestern United States should multiply the above BTU numbers by an “adjustment factor” of .95. Those living in states bordering the Gulf of Mexico, as well as Georgia, the Carolinas, Arkansas and Missouri would multiply by a factor of 1.05. Residents of the Southwest, perhaps the hottest part of the country, should multiply by 1.10.
Also keep in mind:
• Reduce capacity by 10 percent in very heavily shaded areas; increase capacity by 10 percent in very sunny areas.
• Reduce capacity 30 percent if the air conditioner is to be used primarily for nighttime cooling.
• For areas occupied by more than two people, add 600 BTUs for each additional person.
• If area to be cooled includes a kitchen, add 4,000 BTUs.
Other points to look for? “Check the efficiency rating,” says Rogers. “The higher the EER, the more economical it is to run.” But the higher the EER, the larger the internal heat exchanger, which ordinarily increases the unit’s size. “Companies like Panasonic have incorporated major design enhancements to keep efficiency to keep up and size down,” adds Rogers. “But it’s something to keep in mind when you shop.”
Anything else? “Noise,” says Rogers, “is another important design element.” But the test for that is easy. “Plug it in at the store and simply listen. You could hear significant differences between brands.”

hianifooter.gif (43872 bytes)
11 Virginia Rd., White Plains, NY 10603 914 328 1992
To advertise with Home Improver please click here!
Click hereTo have your own site Created or Hosted
Copyright 1999, by HomeImprover Magazine - Maintained by S.E. Online !
Last Revised: Wednesday, February 17, 1999