Patent ID: 8452489

Claim:
A controlling system for controlling an air handling system, the air handling system comprises an air cleaning unit having an upstream side and a downstream side, the air cleaning unit being arranged to pass an air flow into an enclosure positioned at the downstream side of the air cleaning unit, the air handling system being arranged to operate in recirculation mode or in an outside-air-inlet mode, the controlling system comprising: a first sensing unit arranged to generate a first output signal based on a first measurement performed in air at the upstream side of the air cleaning unit; a controller arranged to switch the air handling system into recirculation mode when the first output signal exceeds a predetermined threshold value; and a second sensing unit arranged to generate a second output signal based on a second measurement performed in air at the downstream side of the air cleaning unit, wherein the controller is further arranged to fine-tune settings of the air handling system based on the second output signal.