Water cooling system for a painting plant

One of the essential conditions for high-quality spray painting is maintaining proper temperature and humidity levels inside the paint booth. To achieve this, the booths are equipped with air treatment units that use chilled water supplied by a chiller for cooling.
At the beginning of 2017, the company implemented a painting system to process specific components for the automotive sector, where key requirements included high productivity, continuous operation 24/7 all year round, and strict quality standards for painted parts.
More specifically, the specifications required a chiller with a cooling capacity of 340 kW (conditions: 35°C ambient temperature and 9°C chilled water outlet). However, the installation site’s ambient temperature can vary significantly from the design conditions, ranging from -25°C to 45°C.
This project marked the first collaboration between the company and Cosmotec, initiating a new partnership

cosmotec proposed a chiller from the Techno WPA series, specifically designed for process fluid cooling. This air-cooled unit features four scroll compressors divided into two independent refrigeration circuits. This configuration ensures service continuity: in case of a compressor failure in one circuit, the other circuit remains operational thanks to the active pair of compressors. For added reliability, the system was also equipped with a redundant pump pair.

Given that the ambient temperature could drop as low as -25°C, cosmotec recommended a unit equipped with heat exchangers for free cooling, integrated in series with the condensers. This solution takes advantage of ambient air to cool the water, reducing energy consumption during colder periods.
When the ambient temperature exceeds the return water temperature from the system, the chiller operates with its compressors. If the ambient temperature drops at least 2 K below the system’s return water temperature, the water is pre-cooled by the free cooling coils before reaching the evaporator, reducing the load on the refrigeration circuits (mix mode operation). When the external air temperature is approximately 15 K lower than the return water temperature, cooling is fully managed by the free cooling system, with the compressors completely deactivated, thus maximizing energy efficiency.

The integration of the mix mode operation allowed the system to take advantage of even slight temperature differences between the ambient air and process water. This approach proved particularly beneficial in temperate climates, where such conditions frequently occur, significantly impacting the overall energy efficiency of the system.

cosmotec’s ability to customize the product to operate down to -25°C, the integration of free cooling technology with mix mode to optimize annual energy efficiency, and its flexibility in delivering tailored solutions to meet customer needs were key factors in the company’s decision to entrust this project to Cosmotec. The collaboration was further strengthened at the end of 2017 with the supply of an additional Techno/Explorer series chiller, consolidating a partnership that remains active to this day.

Chiller reliability

Water temperature stability

Service continuity

Energy efficiency