When delivery services deliver or pick up goods at the warehouse door or loading ramp, the open door causes air mass movements, as thermally different air masses always tend to balance each other out. Warm air escapes in the upper door area and cold air coming from outside flows inside and causes energy losses. In principle, this is no different in cold storage or deep-freeze rooms, even if the energy loss is reversed here, since the air entering from the outside must be cooled down again so that no icing occurs or the legally prescribed cold chain is not interrupted.
What to do if the warehouse cools down too quickly because of draughts?
For reasons of faster loading and unloading, industrial doors are happy to remain open during delivery.
This is why many logistics companies opt for invisible “gates made of air”. These air curtain solutions create an “air curtain” through physical effects, either of warm or cold air. This air curtain can have 2 different orientations:
- the air curtain starts immediately above the gate and extends to the ground. See fig. 1 below!
- the air curtain can be created by 2 standing air curtains to the right and left of the door, whereby the air curtain must be at least as high as the door opening. The air jet then runs horizontally – from one side to completely the other side of the The air jet then runs horizontally – from one side to completely the other side of the door (from the left as well as from the right). See fig. 2 below!
In this way, the mechanical door can remain open. The vehicle can stand in the door area during loading and unloading without cold air entering the room or warm or cool air escaping.
The better alternative
Some companies use louvre curtains to reduce the air exchange at the gates. The disadvantages of these louvre curtains are: limited visibility for delivery traffic and heavy wear of the louvres by the delivery traffic passing through. The exchange of differently conditioned air masses is usually only guaranteed to a limited extent. In deep-freeze logistics, icing of the slats often leads to breakage of the slats and an increase in the risk of accidents.
From experience, the air curtain for industrial doors is the better alternative for us because there is no wear of physical elements and the effect is better achieved than with PVC slat curtains.