Challenge
Rockwool, a global leader in sustainable stone wool insulation materials, is based in Roermond, Netherlands. To meet growing demand for one of their flagship products, Rockpanel facade cladding, Rockwool needed a new paint line. To accommodate this, they constructed a new hall adjacent to their existing production facility.
Rockwool commissioned the engineering firm Volantis to devise a sustainable, gas-free solution to generate the high temperatures required for the new paint line. The process involves spraying Rockpanel sheets in preselected colors and passing them through ovens to dry the paint quickly and effectively, ensuring a scratch and weather-resistant finish. This process requires temperatures of up to 97°C.
Solution
Volantis turned to Trane’s advanced heat pump technology, specifically the Trane CXAF air-to-water heat pumps and Trane Exergy industrial heat pumps.
Jean-Pierre Coenen, Project Leader at Equans Netherlands, explains: "Volantis specified the use of Trane heat pumps for a reason. The Trane Exergy industrial units are capable of achieving the extremely high temperatures we need for the Rockpanel paint line."The innovative solution involved using the CXAF air-to-water heat pumps as a heat source for the Exergy industrial heat pumps. The CXAF units, installed on the roof, extract heat from the outdoor air and provide a temperature of 45°C. This heat is then transferred to a 3000-liter buffer tank in the technical room. From there, the water is sent to the Trane Exergy heat pumps, which elevate the temperature to 97°C. This high-temperature water is stored in another 3000-liter buffer tank located near the production lines.
Jean-Pierre Coenen elaborates: "The system is designed to retain heat as long as possible. After the 97°C process heat is used in the paint line, the return water, which might be around 80°C, is reheated by the Trane Exergy units back to 97°C. They can easily maintain that temperature. The CXAF units are primarily used for preheating during startup.”A Trane Exergy heat pump delivers performance that was previously not possible. The maximum condenser temperature of the Exergy is even 120°C. However, for a small part of the Rockpanel paint line, an even higher temperature was needed. Flow heaters are now used for that. Unfortunately for Rockwool, there is no heat pump solution for that yet, not even from Trane. However, the vast majority of the paint line (ten out of eleven consumption points) is entirely sustainable.
Results
The project was executed by Equans who installed the four heat pumps in the new production hall. Trane handled the commissioning, ensuring everything ran smoothly. Test runs began in April 2024, and the new Rockpanel paint line is now fully operational.
Jean-Pierre Coenen of Equans Netherlands notes: " This is the first production line at Rockwool in Roermond with sustainable heat generation. The successful implementation has made Rockwool even more enthusiastic about further greening their production processes. The Trane Exergy heat pumps prove that high process temperatures can be achieved sustainably."
The annual energy and CO2 savings from using the heat pumps can reach up to 80%. Rockwool is very satisfied with the new sustainable paint line and is now exploring ways to convert their existing gas-fired production lines to gas-free operations.
The Trane Exergy industrial heat pump has delivered a groundbreaking solution for Rockwool, enabling high-temperature process heating in a sustainable manner. This project not only meets Rockwool’s immediate needs but also sets a precedent for future sustainable initiatives within the company.
