Virtually every warehouse across the country has the equivalent of an open door policy – whether they like it or not – and according to industry ­estimates it is costing owners around £15,000 a year in additional energy costs alone. But now this is an issue that can be easily solved thanks to Airbloc, a specialist in cost-effective air curtains

Providing a comfortable and safe working environment is a legal requirement, but when doors are left open, the building’s protective barrier is removed. Warm air, therefore, isn’t kept in and cold air isn’t kept out.

This leads the premises into a vicious circle, whereby the heating system is constantly battling to keep a consistent temperature. Energy is used to heat the building, much of which is then lost through the door. Cold air enters, meaning the heaters must work even harder – using more energy – to try and maintain a level atmosphere.

In the worst cases, approximately 36,456kW/hr could be lost in a week in the winter months, in warehouses which operate 24 hours a day. This is based on a facility that must maintain a constant temperature of 17°C. On top of this, the cost of recovering the heat lost when a door is open can amount to over £10,000 in the course of a year.

Based upon seasonally adjusted figures for a 6m x 6m doorway open for 24 hours a day in a building in operation for 215 days during the October-April heating period, the total cost of energy wasted would be £16,770. Furthermore, these figures only show the cost of heat loss. It is impossible to calculate how much more is wasted through cold air gain, but this will cause a further drain on resources. The heating system would need to compensate for both heat loss and cold air gain to restore comfort temperatures.

Such wasted energy is very bad news for any business’ environmental targets. With so much heat required to counteract this energy loss, the carbon emissions of that particular building can sky-rocket needlessly.

An over door air curtain can significantly cut down the costs of heat loss and reduce cold air gain. Put simply, it can protect and maintain internal temperatures when doors must be opened.

It delivers a curtain of ambient or warmed air across the doorway at constant velocity. It separates the internal and external environments, keeping conditioned air inside the building, preventing heat loss and cold air gain – like an invisible door.

To achieve an efficient, low energy solution, the air curtain must incorporate high performance features, such as uniform linear flow across the full door width and fan speed control. Airbloc air curtains, which are engineered for low energy consumption, have been shown to reduce the costs by up to 80 per cent. That’s a considerable cost saving, one that is even more vital in the current economic climate.

Air curtains have advantages over other types of doorway solution, such as high speed roller shutter doors. A high-speed door cannot prevent cold air infiltration or warm air escape while it is open, however fast it then closes. Air curtains can. They also, by their transparent nature, offer better visibility and safety – a stream of air cannot be damaged by fork lift trucks and drivers’ vision isn’t impaired.

It’s not just winter where this solution is effective. Each time the door opens, warm air flows out through the upper half of the doorway while denser cold air from outside rushes in through the lower half. In summer, when buildings are air conditioned, the opposite applies. An air curtain remains effective all year round.

In any industrial warehouse, staff can enjoy a comfortable environment; tonnes of emissions can be prevented from entering the environment and thousands can be saved with a simple, cost-effective air curtain.