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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28 Q4 2018 THE QUARTERLY A Situated over cook lines, ventilation systems remove cook- ing heat, effluent and odors. Type I ventilation systems are grease rated for po- sitioning over grease-producing appliances, including ranges, griddles, fryers and charbroilers. Type II or B units, also called vapor hoods, are designated to handle heat and steam over dishwashers and some oven types. Size and shape of these units depend on the equip- ment. Low proximity style hoods sit closer to appliances. Typical uses for these hoods include quick service restau- rants with fryer banks or kitchens with low ceilings. The de- sign of island style hoods makes them suitable for place- ment in the middle of the room. Filtering options or grease removal devices depend on the ventilation process, the system's design and the level of grease extraction necessary. These range from low-tech baffle systems to high-efficiency ex- tractors. Utilizing more filters can help control grease buildup. Pollution control systems remove smoke, grease and odors be- fore these reach the air- stream. The two types include a filter style unit that utilizes carbon and an electrostatic reciproca- tor or ESP. The latter charges particles as they go through the unit and collects them, while using carbon for odor removal. Filtered units cost half as much up front and twice as much to operate and the opposite is true for ESP units, which also have an auto- mated wash system so filters don't need replacing. Ventilation systems come equipped with exhaust fans that can mount either on the facility's roof, which is most common, or an outside side wall. Belt or direct drive fans are available, although direct drive has become more common, as it doesn't include a belt that can be prone to breaking. For this reason, direct drive requires less main- tenance and has a reduced risk of downtime. When unbalanced or poorly designed kitchen exhaust systems can allow heat and smoke to spill into the kitchen, it negatively impacts air quality, back-of-the- house temperatures and utility bills. This also compro- mises cooking equipment. Ventilation systems' make-up air units prohibit negative pressure in the back of house, improving air quality. The load generated by cooking units will determine how much make-up or replacement air is needed to balance the environment. In addition, the air velocity around the hood needs to be minimized, or the ventilation system may be com- promised. Four types of systems can accomplish this: one system brings in untempered air from outside into the kitchen; another brings in outside air and heats it; a system is available that brings in outside air and cools it and another both heats and cools outside air, depending on the temperature needed. DOAS or Dedicated Outside Air Systems also are available that provide complete tem- perature and humidity control of makeup air. Ventilation systems' fire suppres- sion equipment and controls typically incorporate tanks of chemical agents that are activated mechani- cally to contain or extinguish fires. Newer systems have unlimited water sup- plies for this purpose. When a sensor at the duct connection gets to a certain temperature, this fire suppression sys- tem is electronically activated. Also, bigger hoods with more over- hang and end panels can help contain fires. Demand control kitchen ventila- tion or DCKV automatically varies the ventilation system operation to accommodate peak and down peri- ods. This is accomplished with heat only, where sensors or optics measure the heat differences between the hood and the room. DCKV also can react to both the heat and exhaust, which typically results in a quicker reaction time. It's important to check regulations, as some state codes require DCKV if there are 5,000 CFMs (cubic feet of air per minute) of exhaust or more. Although these sys- tems can be costly, the return on investment with energy savings is generally under two years. Purchasing Considerations When choosing a ventilation hood, operators should weigh a number of factors. "Type 1 is required per code for any equipment that reaches over 400 degrees F and Ventilation Systems

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