Professional air conditioner maintenance

Air conditioning requires more than just regular do-it-yourself maintenance. Hiring a professional service technician is important to find and fix problems involving areas like duct air leakage (in central AC), inadequate airflow, incorrect refrigerant charge or improper sizing. These areas are responsible for large energy cooling wastes.

Be aware, anyway: there are many incompetent service technicians within the HVAC companies.

See: Contractors and Professional Service Technicians

Duct air leakage

More than 50% of central home AC systems have leaky ducts, which are a cause of poor performance. Checking the ducts of central air conditioners and sealing eventual duct leaks is crucial: recent studies show that they are responsible for around 10% to 30% of central air conditioning energy losses.

For efficiency, ducts must be airtight and sealed with duct "mastic."

Duct insulation and obstructions

Obstructions can also impair the efficiency of the AC duct system. Supply and return registers shouldn’t be blocked by furniture, drapes or other means.

Pay also attention to ducts in places like attics. Ducts subject to high temperatures should be highly insulated to avoid heat conduction. Airtight ducts aren’t sufficient.

Inadequate Airflow

Many air conditioner systems have inadequate airflow due to small-diameter of return ducts. Enlarging these ducts can be difficult or expensive, or a rather extreme solution, but it's often the only option to improve the airflow.

There are however other causes of inadequate airflow: dirty coils, low-fan speed, or leaks and obstructions in the return AC ducts... Checking these possible causes, and solving problems associated to them, is very important.

To test airflow, professional technicians should measure it through the evaporator coil. The duct blower is a common and accurate method to do it, but service technicians may also use methods like the flat plate and the flow hoods.

Improper sizing

See: AC sizing

Other areas

Other areas that should also be inspected by professional HVAC technicians include:

1) thermostat control and checking (see: Thermostat basics),
2) electric terminals and connections cleaning and tightening (whenever necessary it should also be applied a non-conductive coating),
3) belts checking and 4) oiling of the motor...