Work out heat recovery efficiency instantly with clear inputs, formula shown and shareable results.
Sensible effectiveness measures how much of the available temperature difference the exchanger actually transfers: the supply air rise divided by the gap between exhaust and outdoor temperatures. The energy recovered is then the familiar sensible relation 1.08 x CFM x rise.
Effectiveness
ε = (supply out - supply in) / (exhaust in - supply in)
Recovered heat
BTU/h = 1.08 x CFM x (supply out - supply in)
ε = (supply out - supply in) / (exhaust in - supply in). Sensible effectiveness measures how much of the available temperature difference the exchanger actually transfers: the supply air rise divided by the gap between exhaust and outdoor temperatures.
No. This is the sensible figure only. An enthalpy wheel also moves moisture, and its total effectiveness must be assessed on enthalpy rather than temperature.
This calculator takes 4 inputs: Outdoor air entering, Supply air leaving exchanger, Exhaust air entering, Airflow through exchanger. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.