n old times, tap water was used as a cooling mode in many laboratories. At first, this method was seen as a practical solution, but then the users became aware of certain deficiencies. Tap water contains lime due to the damage to many devices and equipments and also it causes to decrease in the performance. It could be removed but it was still causing waste of time which is the most precious thing today. In addition, tap water, in cool winter days, could serve as a good cooler, but when it gets heated with the heat of summer it was not able to fulfill its task. Continuous drain of water crucious damages to the environment and to the economy was a big problem in itself. Due to such reasons, conscious laboratory personnel headed for closed circuit refrigerated circulators.
Chiller equipments which designed for applications that require high cooling capacity, are external circulation featured models. Liquids in baths (water, alcohol, antifreeze, etc.) are sent to different cells and devices with external liquid circulation pump. The liquid which loaded heat where it goes and returns to the bath, is sent to the system with cooling again.