Cooling Tower Calculations
Range = Hot Water Temp - Cold Water Temp
Approach = Cold Water Temp - Wet Bulb Temp
Heat Rejection = GPM x 500 x Range (BTU/hr)
Nominal Tons = Heat Rejection / 15,000
Evaporation = GPM x Range x 0.001 (approx)
- Range: Temperature drop of water through the tower (typically 10°F)
- Approach: How close cold water gets to wet bulb (typically 5-10°F)
- A nominal cooling tower ton is 15,000 BTU/hr (not 12,000 BTU/hr)
- Lower approach = larger, more expensive tower