Foodservice Equipment & Supplies

The Quarterly Product Q4 2018

Foodservice Equipment & Supplies magazines is an industry resource connecting foodservice operators, equipment and supplies manufacturers and dealers, and facility design consultants.

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30 Q4 2018 THE QUARTERLY A produces grease laden vapors," says Brent D. Hall, principel, vice president, Clev- enger Associates, Puyallup, Wash. Energy efficiency and local codes represent two key fac- tors when choosing a ventila- tion system. "For example, in Seattle if you have a Type 1 hood and over 2500 CFMs of exhaust air, per code you have to run a demand control venti- lation system," says Hall. "With these systems, fans ramp up and down in speed so hoods don't operate at full force when they don't need to. Thermostats up in the hood detect temperatures coming off cook- ing equipment and determine how fast fans need to run. These systems are becoming code across the nation for energy savings." An exhaust fan auto start feature may represent another good investment for some operators. "Sensors inside hoods detect temperatures over 90 degrees and hood fans automatically turn on; these won't turn off unless the temperature goes below 90 degrees for more than 15 minutes," says Hall. "This is mandated in many locations, but may become a uniform mechanical code." Operators can choose from different types of control panels, with the sophisticated types costing significantly more. "However, these will be needed for those running multiple hoods to one exhaust fan, which can get pretty complex," says Hall. "It can be difficult hooking up to ventilation system components provided by different sup- pliers. This requires more coordination between kitchen consultants and mechanical engineers." Some accessories can help reduce air volumes, including wing walls or panels. "Forty-five degree 2-foot- by-2-foot or 3-foot-by-3-foot panels help aid in catching air and lower air volume, but these also can hinder acces- sibility to the unit and bring down air volume slightly when needing to make code," says Hall. A growing number of larger cities, such as New York and Los Angeles, now require pollution control units as part of ventilation systems. "This component pulls grease and odor out of the air," says Hall. "It scrubs air coming out of exhaust ducts, as well." Cleaning & Maintenance Considerations Kevin McCaw, field supervisor, Hawkins Commercial Ap- pliance Service, Englewood, Colo., says ventilation hood space is at a premium in today's commercial kitchens. "In many places, it's not feasible to put in a hood," he says. "For new kitchens, mechanical chases need to be created and run ventilation through floors." Ventilation needs professional cleaning every six months at minimum, and fire systems should be inspected at least annually. "The hood has visible filters that should be removed and run through a dish machine once a week," says McCaw. "Cleaning depends on how much grease is in the air and hours of operation, but we recom- mend weekly for hood filters and every six months for hood cleaning as standard." Professional ventilation cleaners have access to each corner and bend of the ducts. It is not recommended operators take it upon themselves to clean out these areas with pressure washers. "This has resulted in many service calls for us, but it's not a bad idea to wipe down hood in- teriors occasionally," says McCaw, who adds that, because there are not many moving parts, ventilation systems can last as long as 60 years, with roof fans lasting 7 to 10 years on average. If the ventilation system is not operating or there is a noticeable vibration, a service technician should be called. "Fans get out of balance if they're dirty and shake themselves," says McCaw. "If there is a big vibration when hoods are turned on, or there is excessive noise, it's time for service." Also, if it feels like there is a wind tunnel in the kitchen, this is a sign the makeup air system isn't work- ing. It causes air pressure and sometimes a sewer gas smell because negative air is being pulled in," says McCaw. "Makeup air is just as important as having the hood running."

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