Work out compressor capacity instantly with clear inputs, formula shown and shareable results.
Compressor capacity is mass flow multiplied by the net refrigerating effect, the enthalpy the refrigerant gains crossing the evaporator. Because a ton of refrigeration is 12,000 BTU/h, dividing gives nominal tonnage, and mass flow per ton is a quick sanity check against published compressor data.
Capacity
Q = mass flow x (h1 - h4)
Tonnage
tons = Q / 12000
Q = mass flow x (h1 - h4). Compressor capacity is mass flow multiplied by the net refrigerating effect, the enthalpy the refrigerant gains crossing the evaporator.
A higher condensing temperature raises the enthalpy of the liquid entering the evaporator, shrinking the net refrigerating effect while also cutting volumetric efficiency.
This calculator takes 3 inputs: Refrigerant mass flow, Enthalpy leaving evaporator, Enthalpy entering evaporator. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.