User Manual

Unrestricted 0 – Siemens Smart infrastructure Page 27
fully open, the variable air volume (VAV) damper must control the supply air between min.
and max. cooling to maintain the room temperature at the cooling setpoint.
Extract air volume control – room pressure control (optional)
Negative or positive room air pressure control must be accomplished by flow synchronization
(air flow tracking). The extract air volume must be controlled to track the supply air volume to
maintain the required offset between supply and extract air needed to achieve the required
pressure. The extract air volume setpoint must be calculated to maintain either a fixed or a
ratio air volume offset between supply and extract air. The extract air setpoint must vary as
the supply air in accordance with the present operating mode.
Product Bundle (B): VAV control via Desigo Room Automation with room unit
and room sensor
Operation
Operating modes
Comfort
The operating mode when the room is occupied must be Comfort.
Pre-Comfort
The operating mode when the room is unoccupied must be Pre-Comfort, allowing the room
to quickly reach the comfort range upon changing to a Comfort mode.
Economy
Economy must be the operating mode in a room that is unoccupied for a longer period (e.g.
planned night setback).
Protection
The operating mode when the building is unoccupied (for example, during holiday periods)
for any extended period of time must be Protection. The operating mode Protection must
protect the building against overheating or cooling down too much.