Chiller Sizing Calculator

Calculate required chiller tonnage from water flow rate and temperature differential.

Required Chiller Capacity
--
tons (with safety factor)
Cooling (BTU/hr)
--
Cooling (kW)
--
Power Draw
--
kW
Leaving Water Temp
--
°F
Flow per Ton
--
GPM/ton (typical: 2.4 GPM/ton)

Chiller Sizing Formula

Tons = (GPM x Delta-T x 500) / 12,000

Tons = GPM x Delta-T / 24

For glycol: multiply by specific heat and specific gravity corrections

  • Standard chilled water: 44°F supply, 54°F return (10°F delta-T)
  • Flow rate: Typically 2.4 GPM per ton for 10°F delta-T
  • Glycol correction: Reduces heat transfer capacity by 5-15%
  • The 500 factor = 8.33 lb/gal x 60 min/hr x 1.0 specific heat

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