Air Curtains Go Beyond the Back Door

Published in Great Taste Magazine, March/April 2015 Issue

Berner Sanitation Certified high performance 7 air curtain over kitchen delivery door.

The California Health and Safety Code (CHSC) has mandated air curtains for more than 15 years on foodservice establishment back doors, including restaurants, hotels and other establishments that prepare and serve food. Insect-attracting dumpsters are typically near back doors, therefore the code’s goal is a chemical-free elimination of unsanitary conditions flying insects create near food preparation.

However, air curtain technology advancements in the last five years have gone beyond the back door. It’s not CHSC code-mandated, but restaurants and food service outlets are now preventing flying insect and energy losses at the customer entrance, drive-thru windows, and even walk-in cooler entrances.

But What is an Air Curtain?

  • Air curtains consist of a metal box with highly engineered air blowers controlled by a switch that’s activated when the door opens.
  • They’re typically mounted above the width of a doorway and disperse a steady air stream across the entire door opening. This “air seal” thwarts flying insects that can’t penetrate the airstream.
  • Air curtains also have an energy-saving benefit, because they separate the outdoor and indoor environments, thus saving air conditioning or heating from escaping outdoors.
  • An additional value is employee and customer air comfort in both winter and summer operation.

While appearance isn’t a major concern for service entry doors, the aesthetics of a visible 3 (L) x 12 (W) x 12 DJ-foot metal box mounted above a front door wasn’t favored so the industry now develops models that lay into the ceiling above the interior doorway and have multiple fan speeds for velocity and sound control. These architecturally recessed air curtains provide flying insect protection, but their ability to minimize energy losses from frequent patron door cycles is driving the trend of front door protection.


Air curtain uses are becoming so popular that manufacturer’s representative, Preferred Marketing Group (PMG) installed front door, back door, and drive-up window demonstration models in its Chatsworth, Calif.-based, demonstration kitchen and education center. PMG, which has sold thousands of air curtains throughout its territory of California and Nevada, regularly invites customers to test demos of every imaginable type of restaurant equipment, including air curtains.

Specifically, PMG uses a three-foot-wide working architecturally-recessed model on the showroom’s front entrance and a three-foot-wide, UL-EPH listed, National Sanitation Foundation (NSF)-37 certified model on its back door. Both units are activated when its respective door is opened.

“We’re seeing a real interest in front door air curtains from both foodservice consultants and chain executives.”

-Tony Valvo, vice president, PMG.

Another recent air curtain development is the Drive-Thru Unit (DTU), which PMG has also installed on a drive-thru window mock-up in its education center. While unprotected drive-thru windows are a valid entry point for insects, the continual inhalation of idling vehicle emissions creates a respiratory hazard for drive-thru clerks, according to the Occupational Safety and Health Administration (OSHA) at its website where they recommend a “reverse-flow fan system” among other solutions.

Walk-In Coolers

Another new air curtain application is on the entry doors of walk-in coolers. Many foodservice and restaurant operators are unaware that the Energy Policy and Conservation Act (Section 312), mandates all walk-in coolers/freezers manufactured after Jan . 1, 2009 include either strip curtains, spring-hinged swinging vinyl doors or other air infiltration reduction methods. Air curtains require less maintenance, are more effective, have a longer lifespan, and offer a safe unobstructed view into the walk-in cooler.

One air curtain proponent is Richard Dieli, FCSI, a principal at institutional foodservice design and consultant firm Dieli Murawka Howe (DM HJ Inc., San Diego, Calif. Dieli has used all of the aforementioned applications in what may be the industry’s most diversified use of air curtains in one facility. Dieli specified air curtains for a military base commissary’s walk-up window, both the interior and exterior doors of a walk-in cooler, the front entrances, and of course, the code-mandated kitchen service door.

The recently-built 25,000-square-foot California-based foodservice/dining facility which serves 12,000 meals per shift includes a 30 x 50-foot walk-in cooler that has air curtains on both the exterior door shipments and an interior door for kitchen access. The walk-in cooler’s 5 x 10-foot exterior doorway prevents the infiltration of 70 to 80 percent of the ambient air, which can often surpass l00°F in the base’s desert location. The air curtain has a field-adjustable three-speed switch for different fan velocities. Besides significant energy savings that could result in an estimated payback within a year, it also reduces maintenance by protecting against coil freeze-ups.

Restaurants with smaller walk-in coolers can take advantage of the industry’s recently-developed walk-in cooler kits. Existing coolers are easily retrofitted with the specially-designed kit because it needs only electrical power hook-up to a control box that’s pre-wired to the air curtain and its magnetic reed door activation switch.

A walk-in cooler air curtain study was recently conducted by an Arby’s franchisee Donoghue & Pivirotto Enterprises Inc., Wexford, Pa ., which operates four locations. The company performed a two-week audited test on a 10 x 12-foot walk-in cooler in Butler, Pa. After outfitting the walk-in cooler entrance with an air curtain, the results state the refrigeration circuit’s compressor ran 1.75- hours less during one week–a 27-percent reduction in compressor run-time and equipment wear-and-tear, the latter which will also produce long-term maintenance savings. The improvement results in nearly 100 fewer operating hours per year for an estimated annual savings of $447 and a 1.6-year payback on a walk-in cooler entrance air curtain.

In an industry where operating expenses are rising due to energy costs, the air curtain can help prevent energy losses at both back and front doors, the drive-thru window and the walk-in cooler entrance, with additional benefits of flying insect prevention.