Re-circulating Chillers

What is a Re-circulating Chiller?

Chillers are refrigerators that cool down samples or processes to preset temperatures by removing heat from one element and transferring it to another, typically air or water. The term “recirculating” refers to the cooling liquid—typically water, water/ glycol, or silicone fluids— that is pumped through the system to be cooled and returned to the chiller. Choice of cooling fluid is critical: The liquid must remain fluid at low temperatures or it will not recirculate; and some good circulators, like ethanol, are highly flammable.

Recirculators are defined in terms of physical size (benchtop to large process units), operating temperature, and cooling capacity

Despite their name, some chillers also provide modest heating, to about 40ºC. These units, which may also cool to about -20ºC, are replacements for water cooling.

Chillers operating down to about -40ºC are relatively inexpensive and use a single compressor. The price jumps significantly for the -40ºC to -95ºC temperature range because these systems use two compressors. 

Other Names:
Re-circulating Coolers, Re-circulators, Re-circulating Baths

Chiller applications include plastics processing and testing, cryogenic testing, cooling lab instrumentation, biology, and chemical synthesis.

One emerging use for chillers is to provide cooling for rotary evaporators, a mainstay of chemistry labs. Many jurisdictions today have enacted strict single- pass water restrictions. These refer to water that is immediately disposed of after use, which has been the norm for cooling water. In many labs today, the water aspirator has been replaced by a vacuum pump, and the cooling water for the condenser with cooling fluid from a recirculating pump. “Some systems daisy-chain two rotovaps to a single recirculator,


Information required to quote on a Re-circulating Chiller

  1. What is your application?
  2. What is your desired temperature?
  3. What is your desired cooling capacity at 20℃?
  4. Do you require tubing and taps? How many meters?

Further Reading

Brochure Tech Note: Selecting a Chiller