In highly sensitive areas such as in hospitals, cleanrooms, animal housing and rooms with stringent hygienic and safety requirements, high demands are place on air handling systems. For hygienic reasons, the air between rooms may only flow in one direction, namely from rooms with higher demands to rooms with lower demands.

The TROX VAV controllers with the LABCONTROL TMA-PS or TMA-PE control component for room supply / exhaust air control and additional room pressure control offer a wide range of possibilities. By supplementing this controller with an external room pressure transmitter, the control of the volume flow balance in the room can be enhanced by a definable pressure control. The current measured room pressure is connected to the room controller. Any deviation from the set value is corrected by shifting the supply / exhaust air difference. The actual room pressure value can be connected to the TCU-LON-II controller both via the analogue input and via the binding of a standard network variable from the LON bus.

The room pressure control is in cascade with the volume flow while taking into account the volume flow balance. This results in stable control, even when the volume flow conditions change rapidly and when doors are opened and closed.