This cooling coil calculator finds the total, sensible, and latent capacity a coil must deliver to move air from its entering condition to its leaving condition. Enter the entering and leaving dry-bulb and wet-bulb temperatures, the airflow in CFM, and the site elevation; the tool returns capacity in BTU/h and tons, the sensible heat ratio (SHR), the moisture removed in lb/hr and gallons per hour, and an optional face velocity from the coil dimensions.
Working from the full psychrometric state of each air stream — not just a temperature difference — lets the tool separate sensible cooling from the latent (dehumidification) load. That split drives coil row and circuit selection, chilled-water flow, and reheat strategy, so getting it right early avoids undersized coils and humidity-control problems downstream.
Sensible: Qsens (BTU/h) = ṁ × 0.240 × (Tdb,in – Tdb,out)
Latent: Qlat = Qtotal – Qsens · SHR = Qsens ÷ Qtotal
Mass flow: ṁ (lb/hr) = ρ × CFM × 60 · Water = ṁ × (Win – Wout)
Enthalpy h and humidity ratio W are computed from dry-bulb and wet-bulb per the ASHRAE Handbook — Fundamentals psychrometric relations, with barometric pressure corrected for elevation so air density ρ is the actual value rather than the sea-level 0.075 lb/ft³. The constant 0.240 BTU/lb·°F is the specific heat of dry air; 12,000 BTU/h equals one ton of refrigeration, and 8.34 lb/gal converts condensate mass to gallons per hour.