Air Curtains 101: An air curtain, also referred to as an air door, employs a controlled stream of air aimed across an opening to create an air seal. This seal separates different environments while allowing a smooth, unhindered flow of traffic and unobstructed vision through the opening. Because air curtains help to contain heated or conditioned air, they supply sizeable energy savings and personal comfort when applied in industrial or commercial settings. Air curtains also help to stop the infiltration of flying insects.
There are two major forms of air curtains: recirculating and non-recirculating (most typical).
Non-recirculating air curtains are more widely used than the recirculating type because they’re easier and less costly to install and have lower maintenance costs.
Recirculating air curtains are mainly used in places with constant foot traffic comparable to supermarkets and store entrances. Berner’s recirculating air curtains are called Air Entrance Systems, as they’re built into the entrance, usually when the entrance is being constructed. They emit air from a discharge grille on one side of the door opening, collect it through a receiving grille on the opposite side and return it through ductwork to the discharge grille. The non-obtrusive wide stream of low-velocity air created by recirculating air curtains is more desirable for separating environments.
– Energy savings through control of air transfer
– Energy savings because of shorter run times of air handler or compressor
– Maintain employee/customer comfort
– Reduce flying insect infiltration
– Unhindered traffic flow
– Unobstructed visibility across threshold
– Increase productivity as a result of stable temperatures
– Maintain usable space around door
– Elimination of ice and fog in cold storage areas
Once the power is on, air is brought into the unit through the intake, enters the fan housing and is accelerated by the fan. This fast moving air goes into a plenum, which allows for a good distribution of air along the total length of the discharge nozzle. Aerofoil-shaped vanes in the nozzle create a uniform air stream with minimal turbulence.
For efficient air curtain performance, the angle of the discharge nozzle must be set correctly. An air curtain nozzle ought to be adjustable to aim inward or outward as much as 20 degrees from the opening.The air discharged through the nozzle creates a jet stream to the floor. Approximately 80% of the air returns to the intake side of the air curtain, and 20% goes in the other direction.
Non-recirculating air curtains could be mounted horizontally above the door or vertically on one or both sides of the door, depending on the space available and the height, width and physical characteristics of the opening. Horizontal mounting above the door minimizes the probabilities of damaging the air curtain. Protective measures needs to be taken if the air curtain is mounted vertically.
The proper size, power rating and features needed for a specific air curtain application must be selected in response to the following considerations:
– The physical dimensions of the opening, including height, width and space available for installation (clearance above the mantle).
– The kind of door being used.
– The type of opening ?customer entry, service entry, dock door, etc.
– The climate. Would supplemental heat on the door be appreciated by the building occupants?
– The prevailing winds and exterior temperatures on outside openings.
– The existence of any drafts resulting from pressure differences on the opening.
Berner air curtains require minimal maintenance. Scheduled cleaning, a minimum of once every three months, will ensure the air curtain works properly and extends the life cycle of the product. Extremely dirty, dusty or greasy environments could require a more aggressive cleaning schedule.
Switch the ability off on the service panel and lock the service panel to forestall power from being switched on accidentally.
Remove the air intake grille for access to the blower housing and motor(s). Remove the bottom access panel on heated models for access to the blower housings and motor(s). Vacuum and scrape (if necessary) to remove the built-up dirt and debris. For instructions on your particular model, consult the suitable installation instructions.
The primary U.S. patent for air curtains (air doors) was issued in 1904 to Theophilus Van Kannel. However, the primary recorded air curtain installation was not made until some 12 years later. Air curtains became increasingly popular in Europe throughout the late 1940s and 1950s. In 1956, Erling Berner brought essentially the most advanced European air curtain technology to the United States and formed Berner Industries, the inspiration of today’s Berner International. The primary Berner air curtains were sold in the United States in 1960 to be used on cold storage doorways. Berner International has been developing, designing, testing and manufacturing air curtains since 1956.