Chiller/Recirculator Selection Guide

Use the following formulas to determine the cooling capacity (in watts) required by your system. We recommend selecting a chiller/ recirculator that has a reserve capacity of 10-20% to compensate for radiant losses through tubing and to the environment.

Immersion Chillers

Watts =	V • ΔT • 70 • k t

V = total liquid volume (liters)
ΔT = temperature difference (°C)
t = heating/cooling time (minutes)
k = specific heat constant
k = 1.0 for water
k = 0.4 for silicone bath fluid 01296-00
k = 0.5 for alcohols

Flow-Through Chillers and Recirculators

Btu hr

= flow rate (gph) • Gc • k • ΔT

(note:

Btu hr

= watts x 3.41)

G_c = weight of coolant (lb/gallon)
   Water: 8.34 lb/gallon
   Silicone bath fluid 01296-00: 7.09 lb/gallon
   Ethylene glycol/water 01294-30: 7.5 lb/gallon
k = specific heat constant (Btu/lb °C)
k = 1.0 for water
k = 0.4 for silicone bath fluid 01296-00
k = 0.5 for ethylene glycol/water 01294-30
ΔT = temperature difference (°C)