National Trust shows the way to sustainable building cooling
The natural-ventilation strategy for the sustainable building of the National Trust in Swindon is based on opening windows and rooflights controlled by actuators from SE Controls.
A sustainable natural-ventilation system from SE Controls has been chosen for one of the most sustainable office developments in the UK. The new central office of the National Trust in Swindon is designed by Feilden Clegg Bradley and is built on a large brownfield site in the Great Western Railway works. The 2-storey building accommodates 430 staff and has a shop and public restaurant. Sustainable technologies used in this building include photo-voltaics, enhanced thermal insulation, lighting control, heat-recovery and lime mortar. The natural-ventilation system overcomes the need for air conditioning, one of the largest producers of carbon-dioxide emissions in buildings and incurring large running costs. The SE Controls natural-ventilation system is combined with large areas of exposed thermal mass in the form of concrete panels to first floor and roof soffit. The company worked with M&E consultant Max Fordham Llp to design, install and commission the system, which is based around the OSO controller and a series of actuators fitted to windows and a series of roof vents. There are 307 actuators on 213 windows and 156 actuators in 78 roof vents. The OSO controller acts as an intelligent interface between the actuators and the building-management system, with communication via a LonWorks interface. As carbon-dioxide concentrations or temperatures in the building rise, the windows are opened to let cool air in and the rooflights are opened to allow the warm, stale air out. As temperature and carbon-dioxide concentrations fall, the windows and rooflights close incrementally. During the summer, cool air is admitted by night to cool the exposed concrete roof soffit and first-floor slab. Each window has an over-ride switch so that occupants can open and close windows themselves. Such actions are monitored by the BMS.