It's curtains for PVC slats
December 1st 2005

Mike Verney, sales director at JS Air Curtains, looks at the advantages of using air curtains over plastic slats or internal roller doors

Air curtains are a must for any logistics operation looking to separate different temperature zones whilst also maintaining health and safety. No other system can provide unhindered access, 100% visibility and an effective barrier to stop cold air entering a warm zone or warm air entering a cold zone.

An air curtain is situated above or to the side of an entrance, and provides a powerful blast of ambient or heated air across the opening, reducing air flow through the doorway. This can result in faster loading and unloading operations, energy savings and improvements in staff comfort as well as safety.

The more traditional ways of maintaining temperatures in warehouses and loading areas involve using PVC slat curtains or fast acting roller doors. However, both these methods have disadvantages that air curtains can solve.

Improve visibility

A major disadvantage of using PVC slat curtains is that they rapidly lose their transparency from the build up of grease, dirt and scratches. Consequentially this impairs the vision of forklift drivers as they manoeuvre through doorways, which can be a dangerous health and safety risk to other staff. To maintain the transparency of PVC slat curtains frequent cleaning or replacement of the slats is essential.

By using an air curtain to separate two zones in a loading bay, 100% visibility is maintained at all times.

Maintain temperatures

Using fast acting roller or shutter doors can leave storage areas susceptible to adverse weather conditions, allowing the outside temperature to cause hot or cold spots during loading.

By using an air curtain in association with an exterior door, internal conditions are maintained, even during loading operations. This helps keep produce in perfect condition, improves staff comfort, and reduces the load on the refrigeration or heating equipment thus saving energy and prolonging the equipment's life.

Clients have been surprised at the effectiveness of the seal obtained with an air curtain. An air curtain installation at Nature's Way Foods in Chichester maintains a temperature of 2°C directly inside a chill store when previously there were hot spots of up to 8°C by the door. Tests carried out at another installation at Zwetsloots, The Flower People, in Bedfordshire, found the air curtain maintaining 12°C, the exact same ambient temperature as the rest of the building, directly outside a chill store of just 4°C. This resulted in substantial energy savings and improved staff comfort.

Speed up operations

An internal loading bay door is a hindrance to forklift drivers as they have to stop, get out of the cab, push a button to open a roller or shutter door, get back inside the cab and then drive through. Over the course of a year, these delays add up and can amount to days of labour being wasted on drivers opening and closing doors.

With an air curtain the door can be left open at all times reducing the risk of temperatures inside a warehouse or cold store being affected. This will make loading much more convenient for drivers and significantly speeds up operations.

Reduce maintenance

Fast acting roller doors are also frequently in need of repair, either through malfunction or collision with forklifts. This can be a major expense. With an air curtain this expense is eliminated as they don't need any maintenance and can be fitted and forgotten.

Another advantage of using an air curtain is that it reduces the ingress of foreign bodies into the building. This can be anything that is blown or flies in, for example, insects, dust, litter and leaves or it can be more unhygienic and damaging bodies like rats and mice. The constant wall of air simply blows away litter and also acts as a powerful deterrent to furry intruders that don't seem to like the sensation it creates.

Air curtain options

There are various models of air curtain available for warehouse environments; units for keeping the cold out of loading areas, units that keep cold air in chill stores and freezers, and some for smaller internal doorways. It is important, when selecting an air curtain, to get expert advice otherwise you may find you are paying more than you need to run an oversized unit or haven't got enough power to effectively seal an entrance and lose the benefits of the initial investment.

Depending on the size of the doorway, air curtains can be mounted horizontally on doorways up to around 7m high or vertically at both sides of a doorway up with 14m wide. Modern air curtains are very powerful and this flexibility enables them to be used on the majority of industrial doorways.

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