This month we are discussing the basics of

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1 News from the Network Getting the Most from Your Cooking Equipment Good Ventilation is Good for Business by Tom Stroozas, CFSP Manager Commercial Marketing Piedmont Natural Gas This month we are discussing the basics of kitchen ventilation with some good suggestions on how to make a marginal exhaust system perform better and mention some new technological advances for one of the most frequently ignored appliances found in today s foodservice establishments. Good ventilation is important for the comfort of occupants in any enclosed space. In the foodservice environment, with an array of various types of cooking equipment, a properly performing exhaust system is essential to deal with the effects of heat, cooking effluent (grease and smoke), odors, moisture, pollutants and other airborne contaminants. Without adequate ventilation, cooking in confined spaces would be nearly impossible. The amount of ventilation required in a particular cooking area depends on various factors: the type of product(s) being cooked, the structure which houses the cooking area, the type of equipment used and local code regulations. And, depending on your location, the building heat source may also play a factor. The Importance of Ventilation Ventilation is the single most important factor in the design, construction and operation of commercial kitchens. Without adequate ventilation and an ample supply of clean make-up air, no kitchen will operate efficiently. To ensure proper ventilation, you must consider the following: National, regional and local codes are becoming increasingly strict. Environmental standards are being tightened to require even cleaner exhaust. Increasing costs are forcing the industry to find innovative means to provide lower cost installation, start-up and improved operating efficiencies. The Cooking Equipment Factor The type of cooking that an operation does and the equipment used has a direct influence on the design and horsepower of the ventilation system requirements for any given facility. Some kitchens will use more ventilation energy than others simply because of the type of cooking done. For example, kitchens where fryers, charbroilers and griddles are in use generate more heat and effluent than those AVTEC Ventilator Systems CAPTIVE-AIRE SYSTEMS Direct Fired Gas-Heated Make-Up Air CARROLL EnvironAir APU (Air Purification Unit) COOKING FOR PROFIT comes to you compliments of your gas energy provider/june 15,

2 specializing in the preparation of lighter meals such as salads, sandwiches and soups. Ovens used for cooking pizzas and other baked foodstuffs release intense heat when the doors are opened. And, with today s popular steamers and combination oven technologies, superheated steam poses added problems for inadequate ventilation systems. A Look at Hoods The hood is one of the most critical pieces of equipment in any foodservice operation. Without an effective and efficient hood, the extraction of cooking effluents could not be accomplished, and the kitchen would be a most unpleasant place to work. Over the years, terminology has developed in regard to hood types and design. These common terms include backshelf, canopy, SP (supply plenum), CFM (cubic feet per minute) and MUA (make-up air). Hood size is determined by the size and capacity of the cooking equipment. The capacity of the hood itself is expressed in CFM s and is determined by two primary factors: 1. The type of cooking equipment used, i.e. fryers, ovens, charbroilers, etc. 2. Air flow restrictions such as walls, fabricated enclosures, etc. These factors define the velocity and rate of expansion of the air in the generated updraft, Appliances with large, heat-radiating surfaces like charbroilers and grills, produce a stronger updraft than, say, an oven, which is designed to contain the heat it produces within a confined space. The kitchen walls, fabricated enclosures and the type of hood system used determines how much exhaust air is needed. The more enclosed the cooking equipment, the less exhaust is needed for proper ventilation. So, an appliance that is open on all sides requires more exhaust volume than when only one side is open. Backshelf or Canopy There are a number of variations on both backshelf and canopy hoods and that is determined by the type of cooking that is done in a particular facility. Your menu and equipment will dictate which system design is most appropriate for your application. Backshelf hoods are best suited for low cooking surface appliances such as griddles, grills, fryers, etc. Placing the hood in close proximity to the cooking surface requires less exhaust than a canopy hood used in the same application. This makes the backshelf hood a good choice for this type of cooking environment and explains why it is widely used in quick-service and short-order foodservice establishments that typically use fryers and griddles as their primary cooking equipment. The backshelf hood is not suitable for tall appliances or facilities that produce large volumes of effluent or steam. For such applications, a canopy hood is essential. Canopy hoods require larger volumes of exhaust air than the backshelf design. As a result, they are suitable for ventilating any type of cooking operation and are flexible as to where they can be placed; i.e. next to a wall or in the center of a kitchen with a 360º cooking radius. For that reason, canopy hoods are the predominant system used in today s foodservice facilities. Canopy Hood Sizing There are three important issues to be mindful of when determining hood size: EXHAUSTO Grease Fan GSV GREENHECK Ventilation Equipment FRANKLIN MACHINE PRODUCTS Quest Hinged Baffle Hood Filters 2 COOKING FOR PROFIT comes to you compliments of your gas energy provider/june 15, 2005

3 1. Cooking equipment layout: The majority of applications require a six-inch overhang on each side of the cooking equipment surface. An exception to this are charbroilers, which require a twelve-inch overhang. 2. Wall locations: Determine the wall locations around the hood perimeter. If the cooking equipment is against a back wall and in the corner, the hood would require a six-inch overhang on the front of the equipment and a six-inch overhang on one end only. If the hood is to be open on both ends, then a six-inch overhang must be allowed for each end. 3. Height limitations: The ceiling will determine the height of the hood with the front lip generally placed 78 inches above the floor. Although there are no minimum height requirements, it is recommended that the hood be installed at least 75 inches above the floor in order to provide adequate working clearance and headroom. Air Flow & Make-Up Air Every commercial kitchen requires make-up air to compensate for the air exhausted from the cooking environment. It is also essential to maintain a comfortable working environment. This make-up air may be extracted from the building s HVAC system, which is frequently done but is somewhat expensive and inefficient in the long term. It may even be extracted from the HVAC system in the kitchen area or integrated into the hood itself, which is commonly known as a short circuit system. There are many misconceptions that taking air from a conditioned space within the kitchen area is inferior to incorporating a short circuit type system integrated into the hood. Smoke tests, however, have proven the effectiveness of capture only systems that pull make-up air from the room where it is employed. Remember, the objective is to provide a clean and comfortable cooking environment. A less expensive, capture only hood with make-up air from the kitchen area can clear the air and reduce hood expense. For areas with colder climates, the industry now offers direct gas-fired make-up air systems designed to deliver tempered make-up air for installations requiring frequent air changes. Units are available for natural and propane gas applications and for indoor or outdoor installations. A unique feature of these packages is the self-adjusting burner profile plates allowing two-speed and variable-air-volume applications. The plates ensure proper air velocity and pressure drop across the burner for clean combustion. Because the spring-loaded plates react to the momentum of the fresh air stream, no motors or actuators are needed to drive them, nor do they need to be manually set to a specific position. Proper ventilation is essential Cooking produces heat, odors, smoke, vapors, grease and other pollutants. When a ventilation system breaks down, the cooking environment soon becomes a very unfriendly place to work. Thus, a constant supply of fresh, clean air is essential. The ventilation system must exhaust the heat produced and remove the moisture and cooking effluents. All cooking equipment must be allowed to breathe. Proper air flow is required, not only for combustion, but to exhaust fumes and odors and prevent heat and moisture build-up in equipment controls. Too much exhaust can suck the heat out of an oven, preventing it from cooking properly. Too little can cause controls and electronic components to overheat and fail. Knowing what your cooking equipment requires is critical to its performance and operating life. So, proper ventilation can indeed have GREASE MASTER Kitchen Ventilation Systems HALTON Capture Ray COOKING FOR PROFIT comes to you compliments of your gas energy provider/june 15,

4 a major impact on your bottom line! Another reason for proper and efficient ventilation is the need to maintain a somewhat negative pressure in the kitchen area 20% is a general rule of thumb. Negative pressure means drawing air into the kitchen space atmosphere to contain the odors and effluents that a foodservice operation produces. Kitchens that operate under a positive pressure have a tendency to push the cooking odors and effluents outside of the kitchen to the dining area. Have you ever walked into a restaurant that felt humid and smelled of food odors? This is very unacceptable, especially in places of shared common space, i.e. mall food courts, hotels and office buildings where the operator desires a facility with fresh air and no cooking odors. As mentioned earlier, the system design depends on the type of cooking equipment being used. Although the type of equipment required for cooking is one factor, the use of kitchen space is another. Regardless of the source of make-up air, it is necessary that whoever designs your system calculates the make-up air required for your facility. This is directly related to the type of cooking you do (your menu items), your cooking equipment and related building restrictions. Some considerations when calculating make-up air and equipment required are: Minimize make-up air velocities; Maintain a slight negative pressure in the kitchen 20% is a rule of thumb; Local code jurisdictions will prevail. Rx for a Sick Hood Earlier, I promised some suggestions for curing some of the problems common to many of the asbuilt hood systems in use today. Here are just a few: If you have a short circuit hood (integrated make-up air) you can improve the capture without increasing the fan speed by moving your make-up air to the back of the kitchen. Simply have your mechanical contractor redirect your make-up air so that it travels across the kitchen itself and you will see a dramatic improvement in your hood s performance. Incorporate the use of side panels that can be installed on the open sides of your present exhaust hood system. This will, in effect, create a larger chamber for the hood to draw from and improve your overall system efficiency. These panels can be made very economically from stainless steel or plexiglass. A Plethora of Manufacturers There are many manufacturers of ventilation systems that produce a variety of hood designs available today. In the th Edition of the Foodservice Gas Equipment Catalog, you will see many examples of modern kitchen ventilation systems from which you may choose. I hope this brief overview has provided you some valuable insight on the importance of how a properly designed and operating kitchen ventilation system will make your restaurant or foodservice operation more employee- and customer-friendly and contribute to your overall bottom line! Remember, good ventilation is good for business. The Gas Foodservice Equipment Network (GFEN) has developed a Commercial Kitchen Ventilation Workshop that is hosted regionally by participating natural gas utilities throughout the year. For more information on the GFEN series of Commercial Kitchen Ventilation Workshops, please contact me at (704) or me at tom.stroozas@piedmontng.com. QUEST Kitchen Exhaust Hoods STERLING Gas-Fired Rooftop Make-Up Air with Exhaust Fan 4 COOKING FOR PROFIT comes to you compliments of your gas energy provider/june 15, 2005

5 For more information about Ventilation Equipment contact these leading manufacturers from the 29th Edition FOODSERVICE GAS EQUIPMENT CATALOG DI Foodservice Companies (Avtec/Groen) 1055 Mendell Davis Drive, Jackson, MS Phone: (601) (888) Fax: (888) Internet: Pam Holmes, Director of Marketing Services Captive-Aire Systems, Inc Paragon Park, Raleigh, NC Phone: (919) (800) Fax: (919) Internet: Carroll Manufacturing International 23 Vreeland Road, Florham Park, NJ Phone: (973) (800) Fax: (973) Internet: Bill Burrus, President In Canada: Kolmer Installations Ltd Fewster Drive Mississauga, Ontario Canada L4W 1A1 Phone: (905) Fax: (905) Terry Macrae Grease Master 1014 Indian Trail-Waxhaw Road, P.O. Box 309 Indian Trail, NC Phone: (704) Fax: (704) Internet: Ray McDaniel, Product Specialist Greenheck 400 Ross Avenue, P.O. Box 410, Schofield, WI Phone: (715) Fax: (715) Internet: Robert Utech, General Manager Halton Company 101 Industrial Drive, Scottsville, KY Phone: (270) (800) Fax: (270) Internet: Joe Coots, Applications Engineer EXHAUSTO, Inc Northmeadow Parkway, Suite 180 Roswell, GA Phone: (770) (800) Fax: (770) Internet: Gitte P. Hagensen, Executive Vice President Franklin Machine Products (FMP) 101 Mt. Holly By-pass, Lumberton, NJ Phone: (609) (800) Fax: (609) (800) International Internet: Arnold Kimmons, Director, Sales & Marketing Quest Metal Products Ltd. 949 Erin Street, Winnipeg, Manitoba Canada R3G 2W6 Phone: (204) (888) Fax: (204) (888) Internet: Roy Cuddeford, Manager Sterling HVAC Products 260 N. Elm Street, Westfield, MA Phone: (413) Fax: (413) Internet: Ralph Gates, Marketing Manager Reprinted with permission from Cooking For Profit June 2005//June 15,