Latent Heat Evaporative Cooling

Cooling effect from evaporation rate and h_fg.

Run the calculator

Example

You enter

Evaporation rate (lb/hr) 10

You get

Cooling effect 10540 BTU/hr
Cooling effect (tons) 0.878

Details, formula, and sources

Indirect-evaporative supply temperature ≈ T_db − ε × (T_db − T_wb). Latent heat of vaporization for water = 970.3 BTU/lb at 212 °F (used to convert water consumption to cooling output).

ASHRAE Fundamentals psychrometrics by name; classical thermodynamics.

Psychrometric formulas free in published engineering texts.

Estimate. AHJ and licensed mechanical contractor govern. ACCA Manual J / D / S supersede rules of thumb.

Field names used by the API: evaporation_rate_lb_hr, cooling_btu_hr, cooling_tons

Default effectiveness ε 0.85 indirect / 0.70 direct unless user suppliesmanufacturer typical