Dual-Function Floor Standing Shelter Unit

The air handling unit casing is manufactured with an aluminum profile frame. The inner surface of the casing is covered with 0.8 mm galvanized steel sheet, while the outer surface is covered with 0.8 mm painted steel sheet. The casing panels are filled with 25 mm thick polyurethane insulation. The supply fan is a double-inlet, high-pressure, belt-driven type. The electric motor can be selected as single-phase or three-phase, depending on requirements.

Inside the unit, a G4 or F7 cassette filter is used as a pre-filter. For use in emergency situations, an activated carbon filter and a radioactive HEPA filter are installed. Optionally, a lead separator can be added, and the inner surfaces can also be lined with lead sheets.

System operation begins when the fan is switched on. Under normal conditions, the filter damper remains in the closed position while the normal-operation damper is open, allowing fresh air drawn from outside to pass through the cassette filter and be supplied indoors. In emergency conditions, the normal-operation damper must be closed and the filter damper opened. In this case, the fresh air drawn in passes through the activated carbon filter, HEPA filter, and cassette filter before being supplied indoors.

The adjustable air dampers are operated by two control levers. During emergency operation, the emergency damper lever is set to the open position while the normal-operation damper is kept closed. During normal operation, the normal-operation damper remains open and the emergency damper is kept closed.