Passive cooling teams up with air conditioning for low-energy environmental control
A combination of natural ventilation and air conditioning to prevent overheating is contributing to an ‘excellent’ NEAT* rating for a new building for Brent Primary Care Trust. The £18 million Stonebridge Hillside Hub was designed by Edward Cullinan Architects for Hillside Housing Trust.
Natural ventilation is provided by some 60 Passivent Aircool insulated ventilation louvres installed along two elevations on three floors of the Hub’s health centre, which is located in one wing of the 2-wing 4-storey building. Rooms with Aircool louvres also have a Mitsubishi air-conditioning cassette to provide heating and additional cooling when required.
The Passivent can operate 24 h a day to draw cooler air into the building and remove it at high level using the principles of natural convection. An intelligent controller monitors internal temperature and air quality and calls on the Mitsubishi cassette when required.
Aircool units on the lower-ground floor are acoustically attenuated to ensure that conversations are not overheard outside the consulting rooms or on the street below.
The system has been proven in practice to use little more than half the energy required by traditional mechanical ventilation. Capital and maintenance costs are also reduced.
*NHS Environmental Assessment Tool
