Published on Monday, 03 October 2005
Written by Tony Weber, Associate Editor
Ask operators of any stripe what their main concerns are and controlling costs and ensuring food safety will likely be high on the list. With air curtains, DSRs have the opportunity to sell one product that can address both these issues simultaneously.
- Air curtains and doors work by compressing air with direct-driven centrifugal fans and releasing this air down through a directional nozzle. Depending on the unit, the resulting “curtain” of air can stop winds of up to 25 miles per hour or more.
- As with any product, the first question a DSR should ask customers interested in purchasing an air curtain is how they plan to use it. Broadly defined, operators can choose from two types of air curtains: those that use recirculated air and those that do not. Recirculating units draw air from a heated or cooled environment to create a curtain of air that stops non-treated air from entering the area where air is conditioned. This action helps maintain proper temperatures indoors. Operators typically install these air curtains on the inside of an entryway in order to blow heated or cooled air rather than non-treated air on those passing through.
- Non-recirculating air curtains, which are not designed to draw air from only one enviroment, serve a different purpose. Many states mandate operators use these air curtains to prevent insects from entering an area. In these instances, operators should install such units outside of an area's entrance and position the vents to blow at a slightly outward angle to make the air curtains more effective.
- Air curtains offer two main benefits: They can maintain a pleasant dining environment while lowering energy costs, and serve as food safety devices by preventing flying insects from entering a facility. When used at the entrance of a kitchen, they have the added benefit of preventing aromas from entering the front of the house. DSRs should also note that using air doors to separate an operation's smoking area from its non-smoking area is a growing trend in foodservice.
- When selling an air curtain or door, DSRs should know exactly where an operation wants to install it in relation to staff and the front of the house. Different units have different noise outputs, so a loud air door can ruin a diner's meal or hinder efficient communication in a kitchen.
- One popular option for air curtains is a heating function. Standard units rely on electric, steam or hot-water air heating. Most industrial-sized units, such as those used at loading docks, have gas-fired heating as an option.
- As a rule of thumb, operations should not install high-velocity air doors or curtains at customer entrances, since walking though them can be unpleasant for patrons. But in cold-weather cities especially, units at customer entrances should include a heating function for use during winter months.
- In an effort to control energy costs and eliminate flying pests, many quick-serve restaurants install air curtains at drive-through windows. Rather than having these air curtains active all the time, which would drive-up electricity use, these operations should equip drive-through air curtains with an automatic on/off switch that activates every time the drive-through window opens or closes. Since these air doors will only operate for short durations of time, a heating function is not a worthwhile investment.
- Similarly, air curtains installed at doorways can include on/off switches that activate when the door is open. Another feature is a switch for multiple air speed settings, which helps match the level of protection an air curtain provides with the outside environment. Other options include a time-delay switch for high-traffic areas, a thermostat for controlling the temperature of air blown through a curtain and brackets for installing air curtains in spaces where they otherwise could not be hung.
- One phenomenon that DSRs should be aware of is negative pressure. This occurs when an air curtain draws air from inside a building and expels some air outside. The difference in air pressure can make opening a facility's doors difficult. If this occurs, operators and DSRs should consult the product's manufacturer or representative.
- In order to maintain proper operation, air curtains should be cleaned regularly. In addition, many air curtains come equipped with air filters. These filters are often constructed of mesh aluminum and are thus reusable. Staff should clean these filters on a regular basis, as well.