The UK’s gas and electricity providers are once again refusing to rule out further price increases in the coming months, leaving many businesses feeling that heftier energy bills are inevitable and out of their control. However, by looking at where energy is wasted, it is possible to be wiser about where resources are used in order to streamline operational costs and minimise the impact of future price rises. For facility and site managers looking for simple ways to be smarter with energy, the use of air curtains in factories, warehouses and loading bay areas could make a big difference to utility bills. Here, Andrew Saxon, marketing manager at Biddle explains

Most of us will be familiar with the air curtains used in shops and other retail environments, but what people don’t know is that this versatile technology can be utilised for a wide range of industrial and commercial uses too. 

Air curtains effectively minimise the amount of cold air coming into a building through its doorway, keeping the warm air inside. Without an air curtain, heat will escape through an open door as natural convection causes it to be lost from the top, and replaced at the bottom by cold air coming in. 

An incredible amount of heat can be lost in factories and warehouses when external doors are opened. On a typical winter’s day, a factory that uses a standard doorway measuring approximately 4m wide and 6m high, will lose over 100kW of heat as soon as the doors are open. With a correctly installed air curtain, over 80 per cent of this energy can be retained inside the building, resulting in huge savings on energy bills and a more comfortable working environment for staff.

In the past, a lack of understanding about how air curtains work and how they should be fitted has resulted in installations being incorrectly designed, sized or installed. These installations do not generate any tangible energy savings. So how can factory managers ensure they maximise the benefits of this technology?

If you think your factory or commercial premises would benefit from an air curtain to prevent heat loss, the first thing to do is to get the right equipment. Start by measuring the doorway – air curtains should always be specified on the size of the door, not its kW output. Air curtains can be fitted horizontally or vertically, so consider which one would be right for your site.

Once you have chosen your air curtain and where it will be located, its jet stream must be correctly configured in order to maximise energy savings.  The air discharge should reach across the entire height and width of the opening, at a suitable temperature and must be strong enough to counter the volume of air coming in. If the air stream is too powerful or doesn’t have enough velocity, it will not be effective. 

The use of advanced, automatic controls – including weather compensation – can improve energy efficiency by allowing the air curtain to react to indoor and outdoor temperatures, and ensure the equipment is working at the optimum setting at all times. In our experience, manual control settings on air curtains are rarely adjusted, even when environmental conditions change, so money is very easily wasted through not tailoring the equipment’s output to your needs. In addition to reducing heat loss, air curtains can also be used to improve the effectiveness of extraction/filtration systems in buildings with odour, smoke, gas or dust particles that need to be contained. Systems to improve air quality are not geared up to stop unpleasant smells from escaping when doors are opened because they can’t prevent natural convection. Adding an air curtain to a filtration system can minimise the mixing of indoor and outdoor air to stop odours from leaving the building.

When properly installed, the addition of an air curtain to a factory or warehouse doorway can make a significant difference to a building’s overall heat loss.  Without adequate provisions to stop natural convection, heat – and money – will simply disappear out of the door. With energy prices liable to rise again, factory and facility managers should be asking the question – can we afford not to?

Biddle offers the Invisidor range of air curtains, with varying options and designs available for every conceivable application. 


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