AC Efficiency Loss Guide
Why Efficiency Loss Matters
An air conditioner removes heat by moving refrigerant through coils. When the system is clean and charged, it produces useful cooling with less electrical input. Efficiency loss means the same cooling demand needs more power. That extra power becomes a monthly cost. It also increases run time, wear, humidity problems, and peak electrical demand.
Common Causes
Efficiency loss can come from dirty filters, blocked evaporator coils, low refrigerant, poor airflow, duct leakage, weak capacitors, oversized equipment, or outdoor coils with poor heat rejection. A small loss may be normal with age. A large loss usually points to service, measurement error, or bad operating conditions. The calculator compares rated performance with measured performance, so the result is easy to review.
Physics Behind The Estimate
Cooling capacity is the useful heat removed per hour. EER and SEER compare cooling in BTU per hour with electrical watts. COP compares cooling power with input power using the same units. When measured efficiency is lower than rated efficiency, input power rises. The difference between rated power and measured power is the extra electrical load caused by efficiency loss.
Cost And Energy Meaning
The calculator multiplies extra power by run hours, operating days, and load factor. This gives excess energy use in kilowatt-hours. The energy price then gives added cost. A recovery setting estimates how much could be saved if cleaning, repairs, sealing, or tuning restores part of the lost performance. This helps compare service cost against likely savings.
Measurement Tips
Use steady operating data when the compressor has been running. Avoid readings during startup, defrost, or thermostat cycling. Match the capacity rating to the same system mode. For better accuracy, record outdoor temperature, indoor return temperature, supply temperature, and input wattage. Keep notes, so future checks are consistent later.
How To Interpret Results
A low loss may only need filter replacement and normal monitoring. A moderate loss deserves coil cleaning, airflow checks, thermostat review, and duct inspection. A high loss may need a technician to test refrigerant charge, blower performance, compressor condition, and controls. Use measured values from reliable instruments where possible. Treat estimates as planning numbers, not a certified energy audit. Recheck the calculation after maintenance to confirm real improvement.