Rectifier grille

The patented rectifier grille is the key to the success of Biddle’s air curtains, according to research from the Dutch Research Institute, TNO. The findings of the report are based on a two year research programme which tracked and analysed air temperature and velocity patterns at building entrances. It concludes that the rectifier makes a significant contribution to overall energy savings in entrance environs by enabling Biddle’s air curtains to act as an effective barrier to heat loss and an efficient contributor to heat gain. In fact air curtains fitted with the rectifier can save up to 94% of heat energy requirements compared with a door without an air curtain installed.

The framed rectifier unit comprises an integrated pressure chamber linked to a specially profiled discharge grille incorporating ‘long louvres’. In effect the rectifier bundles air prior to release at 35°C in a low velocity, constant lamina stream.

	Open door with Biddle air curtain with rectifier Air stream reaches the floor at lowest possible speed, so that maximum passing-through comfort is guaranteed. Theoretical efficiency > 90%. Heat from the air curtain benefits the indoor climate.
	Open door with air curtain without rectifier Because of turbulence, air stream does not reach the floor so the door is not screened enough. Inefficient because of heat loss Still drafty at the floor.
	Open door without air curtain Much energy loss due to heat loss through open door. Drafty and cold in the building.