In old times, tap water was used as cool out in many laboratories. At first, this practice 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 types of equipment and also it causes to decrease in the performance. It could be removed but it was still causing a 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. The continuous drain of water crucial 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 equipment which designed for applications that require high cooling capacity is 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.
Coolers which produced by Labo are classified in the class of mini chiller devices and do not cause high noise and heat like industrial chiller devices. Labo chiller devices are preferred for their cooling abilities but they are equipped as a heater when it's needed.