Air Conditioning Repair Air Conditioning Repair Preventive Maintenance and System Efficiency

Question 1

How often should air conditioning system air filters typically be inspected or replaced in a residential application?

Accepted Answer

Every 1–3 months depending on usage and filter type

Answer

Residential AC air filters should be inspected monthly and replaced every 1–3 months to maintain airflow and system efficiency.

Question 2

What is the recommended minimum coil cleaning frequency for a residential split-system AC under normal operating conditions?

Accepted Answer

Once per year

Answer

Evaporator and condenser coils should be cleaned at least once per year to prevent dirt buildup that reduces heat transfer.

Question 3

Which tool is used to measure refrigerant system pressures during a preventive maintenance check?

Accepted Answer

Manifold gauge set

Answer

A manifold gauge set is used to measure both suction (low-side) and discharge (high-side) pressures during AC system servicing.

Question 4

What does a high delta-T (temperature difference) across the evaporator coil typically indicate?

Accepted Answer

Good system performance with proper heat absorption

Answer

A temperature difference of 16–22°F across the evaporator coil typically indicates the system is properly absorbing heat and operating efficiently.

Question 5

During a preventive maintenance visit, a technician finds the condenser fins are bent and partially blocking airflow. What is the correct action?

Accepted Answer

Straighten the fins using a fin comb

Answer

A fin comb is the proper tool to straighten bent condenser fins and restore airflow without damaging the coil.

Air Conditioning Repair Practice Test