Work out condenser sizing instantly with clear inputs, formula shown and shareable results.
A condenser must reject the evaporator load plus the work the compressor added, so the duty is always larger than the cooling capacity, typically by 15 to 25 percent. Airflow follows from the sensible relation 1.08 x CFM x ΔT and coil area from Q = U x A x ΔT.
Heat rejection
Q reject = evaporator load + compressor kW x 3412
Air side
CFM = Q reject / (1.08 x air ΔT); A = Q reject / (U x ΔT)
Q reject = evaporator load + compressor kW x 3412. A condenser must reject the evaporator load plus the work the compressor added, so the duty is always larger than the cooling capacity, typically by 15 to 25 percent.
Condensing temperature and pressure climb, which cuts capacity, raises compressor power and shortens compressor life.
This calculator takes 4 inputs: Evaporator load, Compressor power input, Air temperature rise across coil, Coil heat transfer coefficient. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.