AC Questions from Brunswick, GA Homeowners

Check the thermostat first: it should be on Cool, set below room temperature, with the fan on Auto. Then check the breakers and the filter. If the outdoor unit is not running, or it runs but the air stays warm, the usual causes are a failed capacitor or contactor, low refrigerant from a leak, or a frozen coil. See AC not cooling.

A hum without the fan turning usually means the motor or compressor is trying to start and cannot, most often because the capacitor that helps it start has failed. Switch the system off at the thermostat so the compressor does not overheat, and call. Do not open the unit; capacitors can hold a dangerous amount of electricity.

Squealing often points to a motor or a belt on older equipment. Grinding can mean worn motor bearings. Rattling may be a loose panel, debris in the outdoor unit or a failing fan blade. Rapid clicking at startup can be an electrical part struggling. Any loud new noise is a reason to switch the system off and call.

A musty smell usually means moisture is sitting somewhere it should not: a dirty indoor coil, a drain pan that is not draining, or ductwork pulling in damp air from a crawlspace or attic. Mold and mildew grow fast in a warm, humid climate. A technician can find the source and clean or fix it.

Rooms far from the indoor unit, rooms over a garage, and upstairs rooms under a hot roof often run warmer. A large difference usually comes from ductwork: a crushed or disconnected duct, too few returns, or long runs through a hot attic. Closed vents and blocked returns make it worse.

That is called short cycling. It can come from a thermostat placed in sunlight or near a vent, a frozen coil, low refrigerant, an overheating compressor or a system that is too large for the house. Short cycling wears parts and leaves the air humid, so it is worth having checked.

Many people find the mid to upper 70s comfortable in a Brunswick summer as long as the humidity is under control. Setting the thermostat very low does not cool the house faster; it only makes the system run longer and can freeze the coil. Small, steady changes work better than big swings.

During the cooling season, check it monthly and change it when it looks gray or you cannot see light through it. Homes with pets, allergies or construction next door may need more frequent changes. A clean filter protects the coil, keeps airflow up and helps prevent a frozen AC.

Use the size printed on the existing filter or the filter slot, and a pleated filter of moderate density for most homes. Very dense filters can restrict airflow on systems not designed for them. If you need high filtration for allergies, ask a technician whether your system can handle it.

Generally no. Full covers trap moisture against the cabinet and coil, which is the last thing you want near salt air, and they invite pests. If you have a heat pump, it runs in winter too and must never be covered. Keeping the area around the unit clear does more good.

Switch the system off at the thermostat and at the outdoor disconnect, clear leaves and debris from around the unit, then rinse the coil gently with a garden hose. Never use a pressure washer, which flattens the thin fins. A technician can clean the coil more thoroughly during a tune up.

If your system has an access port on the drain line near the indoor unit, pour in a cup of plain white vinegar every few months during the cooling season. Know where the line ends outside and check that it drips on humid days. A drain that stops dripping while the AC runs may be clogging. See AC leaking water.

It is better not to close many of them. Central systems are designed for a certain amount of airflow, and closing vents raises the pressure in the ducts, can reduce airflow across the coil and can end in a frozen coil or leaky ducts. Closing one or two partway is usually fine.

SEER2 is the current efficiency rating for air conditioners and heat pumps in cooling mode. A higher number means the system uses less electricity to deliver the same cooling. It replaced the older SEER rating, so the numbers are not directly comparable between old and new labels.

The label on the outdoor unit tells you. Older systems often use R22, which is no longer produced. Many systems from the last fifteen years or so use R410A, and the newest equipment uses refrigerants such as R454B or R32. The type matters when a system has a leak. See refrigerant leak repair.

It depends on how well it was installed, how often it is maintained, how hard it works and how close it sits to salt water. Long seasons and salty air are tough on equipment here, which is why yearly maintenance matters. A technician can tell you how worn your system looks.

No. A system that is too large cools the house quickly, shuts off before it removes much humidity, and starts and stops more often, which wears parts. The right size comes from a load calculation that considers the house, its insulation, windows and ductwork, not just the square footage.

The capacitor gives the compressor and fan motors the electrical boost they need to start and run. Heat, long run times and power surges wear it down, which is why it is one of the most common summer failures. A weak capacitor can be found during a tune up before it fails completely.