Storing rainwater underground is part of cooling strategy for Kent college
Rainwater stored in an underground tank provides a heat sink to cool the atrium of these new boarding facilities for a college in Kent and also to provide water for WCs and water the grounds.
Some of the latest thinking in controlling internal temperatures in the summer are being applied in a new £4 million boarding block for St Lawrence College in Kent. The scheme devised by consulting engineers Crofton Design will incorporate a system to harvest all rain falling on the building. This water will be stored in a 36 000 litre underground tank to be filtered and used for flushing WCs and watering the grounds. The rainwater store will be used as a heat sink to cool the building in summer, taking advantage of the constant underground temperature of 12°C to provide cool water to circulate through the underfloor heating system to cool the atrium. A mixed-mode ventilation system will also be employed, driven by the natural stack effect, with assistance from extract fans. The ventilation air will be drawn through large concrete underground ducts to pre-cool the air and help control temperatures in the summer. Crofton Design has included underfloor heating throughout the development. It will be supplied by fully modulating gas-fired condensing boilers. M&E services sub-contractors is Halsion Ltd.