Essilor is a French-based international ophthalmic optics company that designs, manufactures and markets lenses to correct or protect eyesight. The organisation was committed to a policy focused on reducing energy costs and water consumption, while remaining consistent with a sustainable development approach.

The need to increase cold production capacity, as well as the age of the existing chillers, were the were the triggering factors for the operation. The company carried out a diagnosis of its refrigeration production facilities and a feasibility study of a new configuration of this production. The aim was to eliminate cooling towers while optimizing cold production and integrating new technologies such as free-cooling.

The solution found was to centralize the cold production for the entire building's cold network (chilled water). The rationalization of the refrigeration production allowed the number of units to be reduced (9 to 4 units), while increasing the power according to the needs. The water chiller operates in free-cooling mode when the outside ambient temperature is low: at this time the compressor refrigeration is stopped and only fan(s) and pump(s) are working. Moreover, a monthly follow-up is carried out, which makes it possible to correct any drift.

This project, which cost Essilor 914k€, created an energetic economy of 358.4 MWh/year, a water consumption reduction of 2800m3/year, a financial economy of 49 887 €/year as well as the elimination of the use of a refrigerant gas with a high impact on the atmosphere.

Other benefits included, maintenance costs savings and the management of the refrigeration production facilitated.