Sterlco S Series Central Chilling Stations - Manual (Page 30)

Page 30 of 77 SCW Series Central Chilling Stations
If you want lower chilled water temperatures, you’ll need to mix
process water with industrial- (not automotive) grade ethylene or
propylene glycol with rust inhibitor to provide protection down to
20°F (12ºC) below the operating temperature you want. Figure 3
below shows the proper mixtures needed to provide protection to
20°F (12ºC) below the operating temperature you want. You can
then reset the freezestat cutout temperature to a temperature of
10°F (6ºC) below the operating temperature you selected.
Caution!
Make sure all freezestat adjustments are performed
by a qualified refrigeration service technician.
The Sterling product warranty does not cover system freeze-up!
Figure 3
Freezing Protection Curve
Ethylene glycol required for evaporator freeze protection
Ethylene
glycol
percent by
volume
Chilled water operating temperature ºF / ºC
60
50
40
30
20
10
0
-50ºF -40ºF
-40ºC
-30ºF -20ºF -10ºF 0ºF 10ºF 20ºF 30ºF 40ºF 50ºF 60ºF
16ºC 10ºC 4ºC -1ºC -7ºC -12ºC -18ºC -23ºC -29ºC -34ºC -46ºC