Central Air Conditioner Questions

• Central air conditioning systems consist of the outside compressor unit, the condenser coil and fan and an interior evaporator coil. This combination works to take warm air, cool and dehumidify it and then send the now-cold air through a system of ducts that deposit the air through vents in the ceiling or on the floor. Certain questions are apt to arise over the course of ownership of your central air conditioning system.

Why Doesn't the A/C Turn on?

• When your air conditioner refuses to kick on, the first thing to examine is the thermostat setting to determine if it has been raised too high for the unit to begin cooling. If the thermostat is not at fault, inspect the main service panel for a blown fuse or tripped circuit breaker.

Why Are Some Rooms Cooler Than Others?

• If one room is particularly warm while the rest of the house is cool, you should inspect the grille register through which air flows from the duct system. The register typically has a component that can be adjusted to turn off circulation into the room or to control how much cool air enters the room. In a situation where the cool air is not being evenly distributed, examine the warmer rooms to see if the registers have been closed.

Why Doesn't the Air Conditioner Work After a Power Failure?

• After a prolonged power outage, you should give the air conditioner about five or six hours before trying to turn it on again. This time is necessary for the compressor to operate correctly. The compressor can actually be damaged by turning the air conditioner on before it is ready.

How Often Should I Change the Air Filter(s)?

• How often you need to change the indoor air filter or filters is dependent upon usage. If your air conditioning usage is continuous during the hot summer months, you may need to change the filter every two weeks. You should at least change the filters every month during summer. How often you change the filter during the winter months is determined by usage of your forced air system as a heater.

How Can I Improve Air Conditioning Efficiency?

• One of the easiest ways to improve the efficiency of your central air conditioning system is to inspect the outside unit for airflow blockage. Remove any clinging vines that are wrapped around the unit's frame. Prune back any vegetation growing around the condenser. Check for bent fins, and use a special tool called a comb to bend the fins back to normal. Planting a tree far enough away not to obstruct airflow but close enough to spread shade over the outdoor unit can also improve efficiency.