About the best way to detract from the comfort of air conditioning is to take a look at your electric bill.
Higher utility rates this summer can translate into higher utility bills, especially when air conditioners are running full blast in the thick of the season.
Before that really hot weather gets here, however, there are several steps homeowners can take to keep their air conditioners running efficiently.
A few of these steps take only time. Others may require a small investment that is often recouped through savings on an energy bill, said David Jones, an energy specialist with the Illinois Department of Energy and Natural Resources.
”Oftentimes, your investment and then some is returned via lower energy bills,” he said. ”Keeping the air conditioner as efficient as possible translates to utility bill savings.”
Central vs. window units
There are basically two types of air conditioners.
A window unit is just that: a small, portable air conditioning unit that hangs out of a window and usually has the capacity to cool a room or two. It is self-contained and plugs into a wall outlet.
A central air conditioning system is usually a whole house system, and cools rooms through the same forced-air ductwork and vents that are used to heat the house. In addition to an evaporator coil located in the home`s furnace, a central system requires an condenser unit outside of the home.
The major advantage of a central system is that it can cool an entire home. ”They provide a better level of comfort in the home than window units,” said David J. Chase, a spokesman for Lennox Industries, which manufactures central air units. ”They`re also less unsightly and less noisy than window units.”
The advantages of window units is that they are much easier to install than a central system. And if you`re only trying to cool a room or two, they are much less expensive.
Selecting a system
Whether choosing a window unit or central air conditioning system, a homeowner should first determine the size of the system needed. Central air system manufacturers usually have guides for measuring your home to choose the correctly sized system.
And the Chicago-based Association of Home Appliance Manufacturers (AHAM)
publishes a form that helps determine cooling capacity for window units (see below).
If you`re considering purchasing a window unit, make sure you have a functioning window and a nearby outlet in the room you plan to cool. Window units can start at $200 and cost much more, depending on their size.
If you already have a forced-air heating system in your home, a central air system can be added easily, and will cost upwards of $2,000.
If your home has radiator or baseboard heat, however, adding a central system will be a more expensive endeavor because of the added cost of sheet metal ductwork. Basement, attic and crawl space access may be needed to install the coils and condensers, and walls may need to be broken to install the ductwork.
For homes with extremely tight spaces, one alternative is a high-velocity air stream system, such as the Space Pak made by Hydrotherm Inc. These central air conditioning systems can fit into compact spaces and their flexible ductwork alleviates the need for sheet metal work.
Another efficiency option to consider, especially for larger homes, is a zoned system. Such systems alleviate the need to cool rooms that are not being used.
”Why cool a kitchen and family room when everyone is asleep at night in their bedrooms?” asks Chase. ”Zoned systems will be the wave of the future and translate into additional energy savings.”
A zoned system can feature a two-speed condenser unit and motorized dampers that close automatically. Or a zoned system can also have two different condenser units: one in the attic to handle the second floor of a home, and one in the basement to cool the first floor.
Saving energy
If you already own an air conditioner, or you`re planning to install a system, there are many steps you can take to maximize its efficiency:
– Keep the filters clean on window units and central systems.
”Any obstruction of air flow will make the motor work harder,” notes Mary Gillespie, a spokesperson for the home appliance manufacturers group.
”The harder it works, the more energy it consumes and the higher your electrical bill.”
On window units, the filter is a usually a thin, sponge-like pad found behind the front panel, says Gillespie. Simply remove the pad, wash it clean and replace it.
On central systems, the filter is the same mesh filter used with the heating system. Filters are found on the furnace system`s air return vent and usually slide into a slot like a slice of bread into a toaster.
”If you can see light coming through a filter, it`s still usable,” says Jones. ”If not, replace it. Because they usually cost less than a dollar, the payback is also immediate.”
– Keep the exterior coils on both window and central units clean and free of debris, advises John Katrakis, a senior engineer with Chicago`s Center for Neighborhood Technology, a not-for-profit technical assistance corporation for Chicago residents.
”With central systems, flush the coils on the outside condenser unit with a hose to remove debris and also get rid of any weeds growing around the unit,” he suggests.
And if your dryer exhaust vent is near the outside condenser unit, you may want to consider moving the vent, he says. ”A tremendous amount of lint comes out of that vent and can clog up the air conditioning condenser.”
A window unit can be cleaned in a similar manner. Unplug and remove the unit from the window and remove the casing on the exterior section, says Katrakis. Flush debris out of the unit and make sure the condensation drip opening (where the water slowly drips out when the unit is running) is clear. ”A large amount of leaves and debris does get through the vents of a unit, especially if you leave your air conditioner in the window year-round,” says Katrakis. But be careful not to damage the fragile coils on the unit, he adds.
– If your air conditioner hasn`t been serviced in several years, call a service company for a cleaning and checkup, Chase suggests. ”The service person will clean the coils, run electrical tests on the compressor and controls, lubricate the blower motor and all moving parts, and make sure there`s no corrosion.”
To save a few dollars on a tuneup for a window unit, transport it to a service shop instead of having someone come out to your home, Katrakis suggests.
– Make sure draperies or furniture are not blocking the cooling vents on the air conditioning units. ”The air flow should be free flowing for maximum results,” Gillespie says.
– Insulation and weatherstripping are also a big plus.
With window units, make sure you properly insulate any window openings.
”Oftentimes, people simply plop the units into the window and don`t bother sealing any holes,” Jones says. ”A tremendous amount of warm air can come through those openings and make the unit work harder. So fill any gaps with foam or insulation.”
With central units, make sure windows and doors are properly sealed to prevent warm air from leaking into the home, he says. Insulation in walls and attics will also help keep a home cooler.
”And don`t leave doors open for a long period of time,” Jones adds. ”A tremendous amount of cool air can escape from a home in just a few moments.” Passive cooling
There are also some passive techniques to keep your home cooler, even if you don`t have air conditioning.
– For example, shade the sunny-or west and south-sides of your home, advises Jones. Deciduous trees, which shed their leaves during the cold months to let the sun in, are the best bet.
But if you can`t wait for trees to grow, shade the windows with
”shutters, shades, awnings, draperies-anything that blocks the sun out,”
he says. ”Shading really pays off, particularly late in the afternoon during the hottest time of the day.”
– Ceiling fans and box fans will also help circulate air and can make an air-conditioned room feel cooler.
And on moderately warm days, turn on only the fan of a central air system if you have a basement. ”The unit will pull up the cool air from the basement into the house,” Jones says. ”The outside condenser unit, which burns up most of the energy, remains off.”
– Exhausting hot air out of an attic, via vents or exhaust fans, can also lower the temperature in the floors below, Jones says.
– Try to minimize the amount of heat your home produces, says Chase.
”Run the dishwasher, washing machine, iron, oven, etc., in early morning hours or late at night when it`s cooler.”
”Keep incandescent light bulbs shut off if you can,” adds Jones. ”They produce a significant amount of heat. And keep them clean, because when they`re dusty, they produce more heat. If you can, use fluorescent light bulbs, which burn cooler.”
For more information
The Association of Home Appliance Manufacturers offers the booklet,
”1992 Consumer Selection Guide for Room Air Conditioner,” for $2. Send your requests to AHAM, 20 N. Wacker Dr., Chicago, Ill. 60606.
A ”Cooling Load Estimation Form” is available from AHAM for 35 cents and a self-addressed stamped business envelope.
The Illinois Department of Energy and Natural Resources has numerous brochures that offer energy efficiency information. Visit the department`s offices during business hours weekdays at 100 West Randolph St., 11th Floor;
or call 312-814-3895 to receive brochures by mail.
