The monastery cellar is located in the middle of the old city center in Beutels\u00adbach, Germany. It includes a gym with showers and changing rooms, which are used by the nearby school, a small cinema, and a large vaulted cellar where events take place. These four rooms were supplied with fresh air by a venti\u00adlation system located in a narrow cellar room, using belt-driven fans. They could be controlled in just two stages. However, as the rooms were often used to varying extents, for example the cinema room often went from empty to full of people, this is a key area where more effi\u00adciency can be gained.<\/p>\n\n\n\n