The building incorporates both natural and mechanical ventilation. Basic ventilation is provided by the HVAC system which operates when either heating or cooling is required, or when natural ventilation provides insufficient fresh air. Each floor of each block has two air handling units which provide air to an under-floor plenum which in turn supplies air to the occupied space using displacement ventilation (see Figure 5). Air is extracted at the ceiling to the atrium via ducts built into the concrete structure of the floor above. From the atrium air passes out through the roof of the atrium (Figure 3), either under natural stack effect though purpose-built openings or under the action of extract fans.
Key points concerning the design
- Combined natural ventilation and mechanical ventilation with air-conditioning and some heat recovery.
- Use of perforated shading panels to reduce direct solar gain while allowing natural day-lighting.
- Use of external insulation to reduce heat loss in winter and to provide internal thermal mass, in conjunction with night-time free cooling to reduce peak summer temperatures.
- Extensive use of natural lighting to reduce energy consumption by artificial lighting.