Issue link: https://www.e-digitaleditions.com/i/58508
Foster Frable You Want to Put a Kitchen Where? In Part II of "Trends inVentilation,"Foster tackles the issue of handling kitchen exhaust in nontraditional spaces ously,one of the challenges can be find- ing alternate means to manage the exhaust—keeping inmind the landlord, neighbors and local codes.This can be especially difficult in urban locations and mixed-use buildings that combine residential and commercial spaces. Even if there is a route for the grease duct to exhaust to the building roof, occupants on the top floor are not interested in smelling kitchen exhaust every day. And with the trend toward using rooftops for recreation or com- mercial space,exhaust issues are multi- plied. Fortunately, difficult ventilation chal- K lenges don't have to mean abandoning a project location. There are proven solutions for the real dilemmas facing foodservice operators.Although at first glance some of these alternatives may seem somewhat costly, realistic plan- ning in the earliest stages of a project canmean ultimate cost savings.This arti- cle will focus on the different types of pollution control systems, how they work, and the costs and installation issues associated with each of them. The Challenges of Cleaning and Deodorizing Kitchen Exhaust The key to the effectiveness of any kitchen exhaust system is the grease extraction efficiency of the primary hood filtration, which occurs well before the pollution control device. Filters vary widely in their effectiveness at collecting the material coming from the cooking surface in different particle size ranges. While none of the grease hood filters are effective at the submi- cron level representing smoke and odor, UV andwaterwash-type hoods improve the efficiency of the overall hood system 20 FEDA News & Views itchen exhaust generates grease, smoke and odor. If a site has not had a commercial kitchen previ- and help capture some smoke and odor as part of removing the grease. Pollution Control Unit (PCU) or Ecology systems come in different types and use different methods to collect nearly all of the remaining grease,smoke and odor. It's important to understand the strength of a system is in its proper sizing for the type and volume of cook- ing that will be produced.A very small compact kitchen that produces break- fast, lunch and dinner in a busy restau- rant can have the same pieces of equip- ment on the same size cooking line as a spacious church kitchen with low pro- duction, but obviously their pollution control needs are quite different. It's also important to note that using a solid fuel device like a wood grill or pizza oven really challenges pollution control systems. First, solid fuel devices make effluent even when you're not cooking.This means that pollution con- trol for a solid fuel application is even more challenging than just the increase in effluent from smoke and soot. Since most codes require separate exhaust systems for solid fuel and conventional cooking, two separate pollution control systems would likely be required. The Science Behind Smoke Control After grease removal, the next step in pollution control is to capture smoke and related particles. There are two main types of smoke control, Electrostatic Precipitation (ESP) and Multi-stage filters (see Diagram1). ESP (often referred to as scrubbers, precip- itators) uses a two-stage method to col- lect particles. In Stage 1, the airstream passes over a high-voltage source, 10,000 volts or more, to ionize or charge the particles, typically with a positive charge.Then the particles pass continued on page 22 Figure 1