Air Curtains 101: An air curtain, also known 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, uninterrupted flow of traffic and unobstructed vision through the opening. Because air curtains help to contain heated or conditioned air, they provide sizable energy savings and increased personal comfort when applied in industrial or commercial settings. Air curtains also help to stop the infiltration of pollutants and flying insects.
There are two major types of air curtains: non-recirculating (most common) and recirculating.
Non-recirculating Air Curtains
Non-recirculating air curtains are more widely used than the recirculating type because they are easier and less expensive to install and have lower maintenance costs.
The height, width, and physical characteristics of the opening will indicate if the air curtain can be mounted horizontally above the door or vertically on one or both sides of the door. A horizontal mounting above the door minimizes the chances of damaging the air curtain. Use caution when mounting a unit vertically.
Recirculating Air Curtains
Recirculating air curtains are typically used in places with constant foot traffic such as supermarkets and store entrances. Berner’s recirculating air curtains are called Air Entrance Systems, as they are 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 returning it through duct-work to the discharge grille. The non-obtrusive wide stream of low-velocity air created by recirculating air curtains is more desirable for separating environments.
Berner air curtains require minimal maintenance. Scheduled cleanings of your air curtain at least once every three months will ensure that it works properly and will also extend the life of the unit. Extremely dirty, dusty, or greasy environments could require a more aggressive cleaning schedule.
For efficient air curtain performance, setting the angle of the discharge nozzle correctly is crucial. An air curtain nozzle should be adjusted to aim inward or outward up to 20 degrees from the opening.
To select the proper size, power rating, and features for a particular air curtain application, consider the following:
To clean an air curtain, begin by turning off the power at the service panel. Once off, ensure the unit does not turn on during cleaning by locking the panel, as well.
Next, 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 for your particular model, consult the appropriate installation instructions.
Air curtains first came to the U.S. in 1904 when Theophilus Van Kannel received the patent for one. According to records, however, the first air curtain installation in the States wasn’t until 12 years later. In Europe, air curtains were becoming increasingly popular during the late 1940s and 1950s. Then, in 1956, Erling Berner brought the most advanced European air curtain technology to the United States and formed Berner Industries, the foundation of today’s Berner International. Used over cold storage doorways, the first Berner air curtains were manufactured and sold in 1960.
To learn more about air curtains, take the free AEC Daily continuing education course online: “Air Curtains: Energy Savings & Occupant Comfort.”
This is an approved AIA course (1.0 LU/HSW hour), and it also qualifies for GBCI, RCEP, and many other organizations’ continuing education requirements.