A number of companies at the Arena Park office location in Hilversum, including NIKE's Benelux head office, have chosen to join forces to make heat supply more sustainable. The biggest challenge was the heat supply in the winter months. In order to be sure of sufficient heat supply, such an installation normally requires a very large buffer capacity. In this case, buffer vessels filled with our Phase Change Material balls were used. As a result, the buffer vessels became much smaller so it could fit into the design contours of the building. Our partner Boonstoppel Engineering has designed this installation. The yield is well above expectations!