What Protects Chillers From Freeze-Ups?

Chiller Features

• An industrial chiller works much like a home air-conditioning unit. The chiller uses a compressor, condenser and evaporator. Water circulated past machinery absorbs the generated heat. The heated water returns to the chiller, running through its components to dissipate the heat. The water returning to the machinery is cool, reflecting a temperature designated by the user at a computer interface control.

Thermostat and Heaters

• The evaporator component within the chiller is the final region where the water becomes cold. As a result, the evaporator is prone to freeze-ups. An internal evaporator thermostat detects temperature variations. If the evaporator becomes too cold, an internal heater activates to balance the evaporator's temperature, effectively protecting the chiller from a freeze-up.

Water Flow

• Another freeze-up prevention technique is using controlled water flow. If water flow valves through the evaporator close, causing limited or non-existent water movement due to a clog or accidental shutdown, a bypass valve reacts. The bypass valve opens and brings a small water flow into the evaporator for preventing a freeze-up. Once normal water flow valves return to full functioning, the bypass valve will close its water flow influx.

Glycol

• Freeze-up protection is also provided by adding glycol to the water flow. Glycol acts as an anti-freeze chemical, effectively lowering the water's freeze point. Lowering the freeze point protects the chiller from freeze-ups at the normal water freezing temperature of 32 degrees. Glycol and water mixture freeze points vary, depending on the ratio of water to glycol within the chiller system.