Indirect cooling
Industrial refrigerating machines

In view of the legal requirements concerning the containment of installations, and despite the contradiction between the risk of leakage from direct circuits and the over-consumption of indirect circuits, the general trend is towards indirect systems, which are safer and whose energy consumption is reduced.

These circuits use a refrigerant to transfer cooling energy from the cooling units to the user stations. Naturally, in the case of heat pumps, they can also transfer thermal energy with a coolant to other stations.

In air-conditioning systems, the refrigerant is generally pure water; its use is limited to an outlet temperature of around 3°C in chillers. If the units are to be shut down in winter and exposed to frost, an antifreeze must be added.

As soon as the temperature to be achieved is close to 0°C to 1°C,...