No Comments »

Design Dilemma: Energy-Efficient Air Conditioning

• Tweet

• Tweet

In the U.S., two-thirds of all homes have air conditioners.  In fact, air conditioning uses about 5% of all the electricity produced in the United States, at a cost of over $11 billion to homeowners. As a result, roughly 100 million tons of carbon dioxide are released into the air each year—an average of about two tons for each home with an air conditioner.

Despite these disheartening facts, there are a few things you can do right now to reduce your energy use by as much as 20%–50% if you’ve got an air-conditioner:

• Replace or clean your air-conditioner’s filters. Clogged, dirty filters block normal air flow and reduce a system’s efficiency. With normal air flow obstructed, air that bypasses the filter may carry dirt directly into the evaporator coil and impair the coil’s heat-absorbing capacity. Keeping the filter clean can lower your air conditioner’s energy consumption by 5%–15%. Filters need to be replaced or changed every one to two-months during a cooling season. If you have pets, you may need to do it more often. You’ll find the filter in the grill of a room air-conditioner.

• Clean the air conditioner’s evaporator coils. Dirt reduces air flow and insulates the coil, reducing the coil’s ability to absorb heat. This reduces the effectiveness of your air conditioner. To avoid this problem, clean your evaporator coil every year. If you’ve got a central air conditioner with an outdoor condenser unit, clear away foilage and brush which could interfere with your unit’s performance.

• Invest in a fin comb. A fin comb will prevent the aluminum fins on evaporator and condenser coils from bending and blocking air flow through the coil.

• Clean condensate drains. Clogged drain channels prevent a unit from reducing humidity. You can address this problem by passing a stiff wire through the unit’s drain channels.

• Check the seal on your window unit. Be sure the window frame makes contact with the unit’s metal case. Moisture can damage this seal, allowing cool air to escape from your house.

• Prepare your unit for winter. In the winter, either cover your room air conditioner or remove and store it. Covering the outdoor unit of a central air conditioner will protect the unit from winter weather and debris.

• Choose a portable room conditioner over central air. Cooling an entire house uses a lot of energy — it’s much more efficient to only cool the areas where you are sleeping or working, by using a portable air conditioner. Two energy efficient portable models include the Newair AC-12000E (pictured above) and the 7000 BTU Haier HPE07XC6 pictured below. The Newair AC-12000E is available from Amazon for $389.95.  The Haier is available from Amazon for $353.

• Consider managing the heat in other ways. Have you noticed that turning on the air-conditioner is almost an automatic response to temperatures above 72 degrees farenheit in the U.S.?  But in many parts of the world, air-conditioning is seldom used. In those places, people know they can keep their homes cool by: 1) using fans which consume much less energy; 2) lowering shades during the sunniest and hottest times of the day; and 3) opening windows to produce cross ventilation.  They also drink lots of water and enjoy an opportunity to slow down. Try going without the air-conditioner for a few weeks to allow your body to adjust to warmer temperatures. You may just discover that you can enjoy the heat of summer!