To maintain the air change rate and the flow direction as per DIN 1946 Part 7, the actual value of all constant and variable exhaust volume flows must be measured and forwarded to the room controller for calculation of the room balance.

LABCONTROL-ANALOGUE
For room balancing, the actual volume flow values of up to seven fume hoods, room controllers or other extraction sources can be connected directly to the TCU-II controller via analogue signals. If a larger number of signals is to be balanced, the addition function (TAG) can be used on the TCU-II fume hood controllers. With this cascading method, any number of recorded volume flows can be integrated. Volume flows that are not measured, such as constant extraction in chemical cabinets, can be adjusted in the software and also enter into the room balance.