Cold Store Air Curtains: How They Maintain Temperature

How Do Air Curtains Help Maintain Cold Store Temperature?

Cold stores live and die by consistency. A few degrees of drift can mean spoiled stock, failed compliance checks, or a compressor working overtime to claw temperatures back down. The trouble is, cold stores also need doors to stay open — for forklifts, pallet trucks and staff moving goods in and out all day. Every open doorway is an invitation for warm air to rush in and cold air to spill out.

This is the exact problem cold store air curtains are built to solve.

What a cold store air curtain actually does

A cold store air curtain sits above (or beside) a doorway and produces a controlled, high-velocity stream of air that runs from ceiling to floor across the full opening. Rather than blocking the doorway physically, it creates an invisible air barrier that separates the two climates on either side — the chilled or frozen environment inside, and the ambient loading area outside.

Because the barrier is air rather than a physical door, staff, forklifts and pallet trucks can move through it freely, without ever having to stop and open or close anything. The doorway effectively stays "open" for logistics while staying "closed" thermally.

Why this matters for temperature stability

Open doorways in busy cold stores, chilled rooms, food production areas and distribution centres are one of the biggest sources of temperature instability. Every time warm, humid air mixes with the cold air inside, the refrigeration system has to work harder to pull the temperature back down — and that constant cycling is what leads to:

Temperature fluctuation at the goods closest to the doorway, which is often where compliance monitoring picks up problems first
Increased energy consumption, as compressors run more frequently and for longer to recover lost cooling
Condensation, misting and ice build-up around the doorway, caused by warm, moist air meeting a cold surface
Wear on refrigeration equipment, from the repeated strain of recovering lost temperature

By reducing the exchange of air across the doorway, a correctly specified air curtain keeps the internal climate far more stable, even when the door is being used continuously throughout a shift.

Built for the demands of cold storage, not just any doorway

Not all air curtains are equal to this task. Biddle's MAT cold store air curtain, for example, uses Multi Air Stream Technology — three separate air streams working together to form a screen between the cold store and the ambient loading area. This is engineered specifically for the scale of temperature difference found in cold storage, handling differentials of up to 30–40°C between the cold store and the adjoining space, keeping ambient and cold air strictly separated even when the doorway is in use all day.

Where a smaller, more constant temperature difference is involved — such as chilled rooms in production facilities, distribution centres, or smaller cold stores within supermarkets — a unit like Biddle's IsolAir2 provides efficient climate separation without the need for heating, keeping energy consumption to a minimum.

The knock-on benefits

Maintaining a stable internal temperature isn't the only advantage. A well-specified cold store air curtain also:

Improves safety by reducing misting and ice on floors near the doorway, and by cutting down on the constant opening and closing of physical doors
Speeds up logistics, since forklifts and staff have unobstructed, continuous access through the doorway
Reduces maintenance costs, as more stable temperatures mean less strain on refrigeration equipment and less risk of product spoilage
Delivers measurable energy savings — in practice, some cold store air curtain installations have achieved energy savings of up to 80% compared with an equivalent electrical unit, and up to 52% compared with leaving a doorway open unprotected

Getting the specification right

Cold store air curtains aren't a one-size-fits-all product. The right unit depends on the size of the doorway, the temperature differential between the two spaces, how frequently and for how long the doorway is used, and whether the application is a full cold store, a chilled room, or a smaller in-store cold area. Getting this specification wrong is one of the most common reasons a cold store still experiences temperature drift even after an air curtain has been installed.

Biddle's team works with cold storage operators, contractors and specifiers to match the right air curtain technology to the application — from full-scale cold stores with large temperature differentials to smaller chilled rooms with more constant conditions.

Talk to Biddle's team about specifying the right cold store air curtain for your site.