Condenser and evaporator coils are the heat exchange surfaces at the heart of every HVAC and refrigeration system. When they get dirty, performance drops and costs rise — often without obvious warning signs.
The Impact of Fouled Coils
A thin layer of dirt on evaporator coils can reduce heat transfer efficiency by 20-30%. On condenser coils, fouling raises condensing pressure, which increases compressor work and energy consumption.
How Coils Get Dirty
- Evaporator coils: dust, lint, and biological growth from humid air
- Condenser coils: outdoor dirt, cottonwood seeds, insects, and exhaust fumes
Cleaning Methods
Professional coil cleaning involves foam cleaners, low-pressure water rinse, and in severe cases, fin straightening. Never use high-pressure washing on fin coils — it crushes the fins and reduces airflow.
Annual cleaning is standard for most commercial systems. Rooftop units in urban environments may need semi-annual attention.