Pressure Relief Valve

Pressure relief valves balance the pressure between the inside of a cold room and the outside. In low-temperature rooms, a pressure difference builds up when warm air enters as the door opens and closes, or during defrost. Pressure relief valves prevent this difference from damaging the doors or panels. Made entirely of durable plastic, the valves can be used down to -50 °C. The flap is fitted with a heater so that it does not freeze as air flows in and out.

The air flow needed to balance inside and outside pressure is calculated with the formula below:

Q = k.V.Δt

Q = Required air flow (l/min)
K = 3.66 (constant)
V = Cold room volume (m³)
Δt = Maximum temperature change in the room (°C) – (change per minute)