Air Apparent

For Boston-area pizzeria, an air curtain proves to be the most effective and less costly indoor air comfort alternative to vestibules and fabric curtains.

By Karen Ryder

Hearth Pizzeria’s interior entrance area was so cold during winter that patrons moved tables and chairs away from the pizzeria’s sunny storefront views of downtown Needham, Massachusetts.

It’s uncertain whether the uncomfortable indoor air from busy door traffic during winter hurt the 2,800-square-foot suburban Boston business, but its owner, Ivan Millan-Pulecio, was sure it wasn’t helping. Due to the chilly entrance, about 300 square feet went unused and its 64-seat capacity shrunk to 50 during busy lunch and dinner periods.

Millan-Pulecio previously tried a ceiling-hung, 16-foot-high red velvet curtain on the interior side of the doorway to block open door drafts. Hearth’s curtain wasn’t inviting to foot traffic, children tended to play with it, and new Hearth patrons found it intimidating to walk through while not knowing what loomed on the other side.

“It was very confusing to new customers and some people likened it to walking onto a stage,” says Millan-Pulecio, who is also executive chef and owner of Hearth Pizzeria’s parent company, Sol Soul Family Foods.

The fabric curtain seemed like the only option until Millan-Pulecio got a recommendation of electric-heated air curtains from Boston-based Boston Showcase, a national foodservice design, equipment and installation firm. Boston Showcase specified an air curtain manufactured by Berner International LLC, a New Castle, Pennsylvania-based leader in air curtain technology.

Millan-Pulecio was unfamiliar with air curtains, but less skeptical after Owen Freeman, vice president of the manufacturer’s representative, Gloucester, Massachusetts-based Pardee, Freeman Inc., presented successful air curtain application examples from retail and other commercial building categories. Collaborating with Millan-Pulecio and Boston Showcase, Freeman was able to suggest the proper model, and control accessories and mounting position.

“We sell air curtains for a lot of foodservice purposes, such as back door models for flying insect control, air comfort at QSR drive-thru windows, energy reduction on walk-in cooler entrances,” says Jeff Sullivan, a Boston Showcase dealer sales rep. “We designed his restaurant with great foodservice equipment, so Ivan trusted our opinion on air curtains.”

Sullivan originally specified other equipment by Bellingham, Washington-based Wood Stone Corp.; Mentor, Ohio-based Cres Cor; Morehead City, North Carolina-based Bally Refrigerated Boxes Inc.; and Baltimore-based Vulcan-Hart Co.

While Millan-Pulecio’s main impetus was indoor air comfort, the air curtain will also help bolster Hearth Pizzeria’s bottom line with energy savings. The air curtain will save $1,141.97 and $306.55 in heating and cooling costs, respectively, for a grand total of $1,448.53 annually (167.7 MMBtu/yr), according to Freeman’s energy calculations. “Our energy bill the first December of air curtain operation was considerably lower than the previous December, even though both months had similar weather,” says Millan-Pulecio.

Berner air curtain over Hearth Pizza doorAn air curtain, sometimes referred to as an “air door,” consists of a highly-engineered combination of blowers, motors and nozzles in a metal cabinet mounted above a doorway. Air curtains draw interior air from the facility and discharge it through field-adjustable (+/-20 degree) linear nozzles that seal the doorway with a non-turbulent air stream meeting the floor approximately at the door opening’s threshold to effectively prevent outdoor air infiltration.

Hearth Pizzeria’s air curtain was designed for 8- to 10-foot-high, 3-foot-wide doorway applications. Sullivan also specified an onboard 9.5-kW heater to provide supplemental heating near the entrance. The unit’s low voltage, two-pole thermostat can be mounted onboard or remotely and is set for a specific recovery temperature set point after a door opening. The deluxe control package includes a time delay that’s factory-set for 60 seconds to maintain operation until timer expiration. Thus, the air curtain runs continuously during high foot traffic periods.

Air Curtain Price Advantages

Besides its mediocre success, Millan-Pulecio’s custom-made fabric curtain cost $6,000, of which one-third went to certified fire-retardant fabric treatments to comply with National Fire Protection Association (NFPA) codes. The curtains have since been repurposed for more of a decorative function elsewhere in the restaurant. “There was also the potential where a fire inspection could determine the fabric curtain was detrimental because it was blocking the entrance’s exit visibility,” adds Sullivan.

Another potential solution was a glass vestibule costing an estimated $9,000. Vestibules help, but when both doors are opened simultaneously, it creates a wind tunnel to a building’s interior. Furthermore, air curtains were proven in a study as more effective than vestibules for conserving energy, which could also apply to cold air infiltration. “Air Curtains: A Proven Alternative to Vestibule Design,” verified by a second-party research/validation consultant, Charlottesville, Virginia-based Blue Ridge Numerics, used computational fluid dynamics (CFD) analysis technology to prove that an air curtain/automatic door combination is 10% more effective in environmental separation performance than conventional automatic two-door vestibules.  

The air curtain has stopped air comfort complaints, made the entire restaurant floor space usable during winter, reduced costly heating/cooling losses through the doorway, and allows natural, unobstructed sunlight into the storefront.

 

— Karen Ryder is a regional sales manager for Berner International, based in New Castle, Pennsylvania. She has 16 years of experience in the foodservice industry and can be reached a kryder@berner.com. Berner International is 61 years old and is a leading manufacturer and innovator of air curtains for foodservice, restaurant, industrial & commercial applications.

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