Architect and Builder Magazine South Africa March/April 2015 | Page 46

The VAV air handling units generate condensate which will be drained by gravity to trapped floor drains in the plant rooms to prevent odours being drawn back into the unit. The wiring closet/nodal rooms and security control rooms require 24 hours cooling with duty and standby units. Each room has two VRF/VRV units which are connected to the duty/standby outdoor units located on the roof of the building via refrigerant lines. The indoor under ceiling units supply air directly into the room via unit mounted grilles. The ablutions, tea kitchens and network rooms are separately mechanically extracted. The exhausts are positioned as best as possible 46 to prevent the re-entrainment of the exhaust air through the fresh air intakes. The kitchen is on the ground floor and has dedicated kitchen canopies extract system complete with built-in make-up air and fire dampers on the extract spigot ducts. The extract ducting (black steel welded) and make-up air ducting is routed to the roof level via a dedicated shaft. The finishing kitchen on level 5 has a dedicated extraction system complete with extract canopy and black steel ducting. The office areas and basements have smoke extraction. The fireman’s lift lobby and relevant staircases are pressurised. Basement parking is Acacia House