Circulating units are used to supply filtered air to a workplace and to protect the product from ambient contamination. The design of the circulating unit, together with suitable regulation, provides uniform laminar airflow at the outlet under the unit, with the required speed in the range of 0.3 ÷ 0.45 m.s-1 (when air density ς = 1.2 kg.m3).

The circulating unit is usually installed in the grid of the heavy FOR CLEAN suspended ceiling. To stabilize the laminar flow, it is recommended to install flexible or fixed screens along the perimeter of the unit, attached to a separate suspension grid structure. When installing the circulating unit in areas without a defined class of cleanliness or in an environment with increased dust generation, a pre-filter is mounted at the suction inlet of the unit.