Free-cooler modules are heat exchangers equiped with a fan which are connected in series with the cooler. Installed outside the manufacturing hall. With respectively low ambient temperatures they release part of the heat being diverted into the ambient air. This unburdens the cooler and thus saves energy. If heat cannot be released to the area due to high ambient temperatures, the cooler must divert all of the excess heat.
For safety reasons, free-cooler modules are only operated with water.