Thanks to a recent remodeling, patrons seated indoors experience the ambience of dining outdoors at O'Toole's Irish American Grill & Bar, except there are no mosquitoes, flies, vehicle emission odors and the temperature is always a comfortable 74 degrees.

The remodel included improvements to the bar area, outdoor patio restrooms, HVAC systems and other improvements. However the most critical factor in creating the outdoor experience is seven air curtains over the 46-feet of retractable glass walls and overhead doors. The air curtains separate the indoor environment from the outdoor elements of flying insects, heat, cold, and nearby street vehicle emissions when the glass walls and doors are opened.

The fact the Royal Oak, Michigan-based restaurant's sales jumped 25 to 30 percent after the remodeling is no coincidence. It proves the open frontage is inviting to passersby and that suburban Detroit patrons prefer an outdoor dining experience, but also want air comfort and indoor air quality (IAQ) as well, says Keith Wadle, the owner and a 25-year veteran of the foodservice industry who opened O'Toole's 14 years ago. Wadle expects the sales increase to deliver a short payback on the renovation investment.

Wadle knew opening up the sidewalk frontage would increase business, but wasn't sure how to keep outdoor elements out until he visited a Florida restaurant that protected multiple open doorways with air curtains. Wadle called the air curtain manufacturer, Berner International, New Castle, Pennsylvania. Berner's Detroit area representative, Buyline Building Products, Rochester, Mich., engineered the project for the best sized models and installed them during the remodel.

During moderate weather in spring and fall, and nearly every day from May through September, Wadle opens up the 30 feet of retractable glass doors manufactured by Nana Wall Systems, Corte Madera, California, plus two 8-foot-wide glass overhead doors. The air curtains, which are mounted to the interior top of the frontage wall, discharge a "curtain" of air that meets just inside the three-foot-high exterior sill. Insects, car emissions, rain, and outdoor air can't penetrate the curtain of air. While energy savings wasn't the primary goal, the air curtains prevent more than 75 percent of the air conditioning or heating from escaping outdoors.

Air curtain selection and sizing was challenging for Buy Line Products President, Rudy Aho. Air curtains are designed for doorways and openings, but typically occupants don't sit in or near the opening. O'Toole's most popular seating is at the frontage and under the air curtains. Therefore, Berner's engineering department customized the blower assemblies for a lower velocity, but they still provide the necessary 1,407-feet/minute at three feet above the  floor (window sill level) for performance. The customization was a factory-tested balance of protecting the opening, but also preventing napkins or paper money tips from blowing off tables. The air curtains also include adjustable three-speed fans for precise onsite environmental separation.

Another customizing feature is the five 72-inch-long Commercial High Performance (CHC-10) model air curtains in the bar area, which are powder coated to match the Irish green decor's color. Berner used the RAL color standard to match O'Toole's green and sent a sample to Wadle for approval before manufacturing. The enclosed patio features two 96-inch-long Industrial Direct Drive (IDC-12) model air curtains with a custom bronze color to match the brown ceiling and exposed spiral round ductwork.

O'Toole's air curtain performance was so successful, Wadle ordered six more air curtains for the newly-opened second location, Too Ra Loo, a family-restaurant in neighboring Rochester, Mich., named after the Irish lullaby. Too Ra Loo's conversion from a former Middle-Eastern cuisine to a family-style restaurant also included retractable windows and the air curtains, which are even more critical for preventing emissions, since vehicles idle at a stoplight 10 yards away.

The air curtains are critical for indoor air comfort, but equally important for indoor air comfort is O'Toole's HVAC system renovation, a design/build project Michael Nabozny, president of the installing HVAC contractor, Pro Mechanical Services Inc., Trenton, Mich. Pro Mechanical Services replaced aging five-ton and 7.5-ton rooftop HVAC units with two high efficiency five-ton units and one 7.5-ton unit all manufactured by Carrier—div. of United Technologies Corp., Farmington, Conn. Nabozny's design divides the restaurant into three zones of the kitchen, billiards/large screen TV and dining zones with their respective rooftop units monitored and controlled by digital 24/7 programmable thermostats by White-Rodgers—div. Emerson Climate Technologies, St. Louis.

Steve's Sheet Metal Shop, Hazel Park, Mich., fabricated rectangular ductwork for down flow and kitchen ductwork, however the restaurants' more aesthetic spiral round duct in the bar and dining areas were manufactured by SEMCO LLC, Columbia, Mo. and installed by Pro Mechanical Services.

Too La Roo's remodel included replacing two 10-ton rooftop systems with three 10-ton high efficiency Carrier rooftop units installed by Pro Mechanical Services. 

The fact Wadle never hesitated to include air curtains when planning his new Too Ra Loo location's remodel is a testament that the technology works and can improve any restaurant's indoor environment, save energy and increase sales.  

Industry News, Restaurant Design