In laboratories, research is also performed outside of fume hoods. To protect neighbouring areas against exposure to hazardous substances, the direction of air flow in laboratories is defined such that air can only flow from adjacent areas into the laboratory, but never in the other direction.
In cleanrooms, however, it may be necessary for air to flow from these rooms to adjacent areas to prevent contamination of the cleanroom area.
The TROX VAV controllers with the LABCONTROL TRA-RS or TRA-RE control component (TCU-II type of operation: room supply or exhaust air) regulate the planned room balance reliably and achieve the required flow direction by means of a constant difference between the supply and exhaust air. For the purpose of balancing, the actual volume flow values of all controllers are continuously evaluated on the basis of the connected analogue voltage signals (0-10 V).
Example: laboratory
To achieve a defined volume flow balance in a room, the room supply air must be adjusted to the actual exhaust air volume flows.
The controller determines the total volume flow of the exhaust air on the basis of all recorded exhaust air volume flows (fume hoods, constant extraction, additional exhaust air). To achieve the required flow direction through the entry points into the laboratory, the supply air controller tracks the exhaust to achieve a constant definable difference in flow (see control diagram).
