Saturday, June 21, 2003
Experts discuss the ins and outs of central air conditioning in the home.
By REBECCA SLOAN
VINDICATOR CORRESPONDENT
When the heat of summer settles in, most folks like to settle down on the sofa in front of the television set.
Well, that is if they live in a home with central air.
Installing central air into new construction is a snap, but what happens if you live in an older home with no central air?
Robert Dieter, of Dieter Heating and Air Conditioning in Canfield, said two key factors determine the ease and expense to have central air installed: the type of heating system already there and the capacity of the electrical breaker box.
Heating systems
If you live in an older home with electric baseboard or hot water heat, be prepared to pay more.
"There are a lot of older homes in the area with these types of heating systems. Since the homes do not have any existing ductwork, ductwork has to be added for the central air," Dieter said.
Sometimes a specialized, high-pressure ductwork has to be installed. This very small ductwork is designed to fit tight places, such as inside walls, and it is very expensive, Dieter said.
For example, installing a standard central air system in a home with ductwork costs about $2,000, but installing a system that requires specialized ductwork can cost $6,000 or more. Central air installation is simpler and cheaper in homes with gas, oil or propane furnaces since the ductwork is already there.
However, Gene Clayton, of Clayton Heating and Air Conditioning in Youngstown, said the cost can go up if the home has an older furnace that needs to be replaced.
"If a furnace is 15 to 20 years old, the homeowner should probably have a new furnace installed because the average life of a furnace is only about 18 years," Clayton said. "You don't want to have central air installed and then have the furnace give out a year later."
That's because the central air system is linked to the furnace, and the evaporator coil that cools the air is installed near the furnace. During summer, the furnace blower circulates the cool air the same way it circulates the warm air during winter.
Electrical requirements
Besides appropriate ductwork and a furnace that's up to par, a home must also have adequate electrical capacity.
"A home has to have at least a 100-amp electrical panel, and there has to be adequate space in the panel for an additional 2-volt breaker," Dieter said.
If the home's electrical capacity is too small, it won't be able to handle central air.
"That's when you have to call in a licensed electrician to bring the equipment up to standard," Dieter said.
The home's thermostat will also need to be rewired so the new thermostat can control both the furnace and central air.
System sizes
Professionals tally the home's square footage when trying to determine what size central air system the home needs. However, professionals also consider several other factors.
"If the home has several windows on its south side, is situated in a yard without shade trees or has a black roof, it will need an air conditioning system with a greater capacity than a shaded home with a gray roof and only a couple south-facing windows," Dieter said.
Air conditioners are sized according to tons. For example, a 2-ton unit will cool a 1,200-square-foot home.
Clayton said most average-size homes require a 2- or 3-ton unit.
The outdoor unit
Air conditioning systems have two parts: The evaporator coil that is installed above or below the furnace, and the outdoor unit, or condenser.
The outdoor unit sits outside and looks like a big box. Its function is to dissipate heat from inside the house.
"Depending on where you live, there are various code restrictions on where the outdoor unit can be placed," Dieter said.
For instance, in many neighborhoods, outdoor units can't be placed in front or on the side.
"Outdoor units are quieter than they used to be, but you still wouldn't want your neighbor's outdoor unit right next to your patio," Dieter said.
Most of the time, outdoor units are installed on the back of the house and sit on concrete or plastic pads.
Maintenance
It's important to keep the coils of the outdoor unit clean.
Professionals shouldn't install outdoor units next to a dryer vent where coils will collect lint, and homeowners should keep coils free of grass, leaves, dirt and dust.
"We recommend that you wash the coils off twice a year. Ask your dealer how to clean your particular unit. Usually you can just squirt them off with a hose," Dieter said.
A properly maintained central air system should last at least 20 years, Dieter said.
Utility bills
Many people wonder how much more their electric bill will be after they have central air installed. Dieter said the cost increase is surprisingly low.
"On average, people who live in this part of the country will run their central air system about 850 hours per year," Dieter said. "Studies show that a person living in a home with a 2-ton central air unit will pay about $1.50 per day for their central air."
Central air is more efficient if it is run continually at a constant temperature. Turning the unit up and down or cooling the house all day and then opening the windows at night and letting in warmer, more humid air will make the system less efficient, Dieter said.
One thing people are surprised to see when they have central air installed is that they no longer have a problem with dampness in their basements or in the rest of their homes.
"Central air helps the basement stay dry. It's a great dehumidifier," Dieter said.