Cold room ventilator

A cold room ventilator equalises pressure between the room and the outside. Without one, opening a door against a pressure difference pulls warm moist air in, and that moisture ends up as frost on the evaporator and as ice around the door frame.

The RSVQ range covers four models. RSVQ-01 fits a 140 x 140 mm hole with a 170 x 170 mm installation footprint, RSVQ-02 fits 215 x 215 mm with 255 x 255 mm installation, RSVQ-03 is the stainless steel version of the 140 x 140 mm size for washdown rooms, and RSVQ-04 fits a 145 x 145 mm hole. Supply is 220 V at 50/60 Hz.

The fan is reversible in practice - it is installed to either pressurise or depressurise depending on how the room is used - and the unit is normally interlocked with the door or with the refrigeration controller so it runs only when needed. Running it continuously simply adds heat load.

Selection is by room volume and by the door size: a small reach-in room needs one unit, a walk-in with a wide door may need two, and the stainless version is worth the difference in a food preparation room where the walls are hosed down.

Installation points: fit the ventilator as high as possible on the wall, away from the evaporator so it does not blow air across the coil, and make sure the external hood is clear and screened - an insect screen that clogs with ice will stop the unit working and is easy to overlook. Check the flap or shutter closes fully when the fan stops, otherwise the ventilator becomes a permanent hole in the insulation.