The temperature of the air supplied to each floor vent in CH2 is approximately 20°C. Fresh air is released from the floor, with swirl diffusers located on movable floor tiles allowing individual placement to suit workstations. Air is only used once and is exhausted by natural convection to the atmosphere.
CH2’s air:
- is treated by filtering, heating or cooling and drying (if needed) in the plant room on the roof
- is pumped from the roof plant room down the supply-air ducts (on the south side) and into the sub-floor space, which is a raised access-floor about 300mm high
- is brought into the office space via the circular outlets (‘swirl’ diffusers) located across the floor on the moveable floor tiles. These diffusers mix the air at low level
- rises as it heats up (from the heat generated in the office from people, lights, computers and so on), so the hot air is moved to the top of the office space
- finds its way, by natural convection, into the void formed by the ‘belly’ of the curved concrete ceiling. This void is connected to the exhaust-air shafts (located on the north side) by a short metal duct
- is exhausted to the atmosphere from vents at the top of the exhaust shafts beneath the yellow wind turbines on the roof.
This one-way air flow is called a ‘displacement’ air flow, which is of great benefit to staff because air that is exhaled rises and is, in turn, displaced by rising fresh air. This means that staff are always breathing fresh air rather than the mix of used and fresh air found in conventionally air-conditioned buildings.
There are two complete air changes every hour in CH2, which means there is about two and a half times the amount of fresh air coming into the building than compared with most conventionally air-conditioned buildings.
This air system also means that the output from coughs and sneezes is being taken straight out of the building rather than being spread around the floor, and around the building. This creates a healthy workplace.