Designing a CaptiveAire Commercial Kitchen Ventilation System

A Buyers' Guide to Commercial Kitchen Ventilation

CaptiveAire supplies restaurants and other foodservice operations across the country with commercial kitchen ventilation systems. Available equipment packages include commercial kitchen hoods, exhaust fans, electrical controls, grease duct systems, fire suppression systems, direct- and indirect-fired heaters, grease filters, and utility distribution systems. CaptiveAire manufacturers its equipment to customers’ required specifications, allowing every element of your commercial kitchen ventilation system to be completely customized to best fit your needs. While you should always work with a professional when designing a ventilation system for a commercial kitchen, the information below will equip you with the knowledge to begin the customization process.

Hood Options

Before you can begin the customization process, you must first determine what your needs are. The types of cooking equipment you have, along with their sizes and locations, will determine what type and style of vent hood will be required.

Kitchen Equipment

Consider what types of cooking equipment are in your kitchen to determine the exhaust volume your hood will need to move. Airflow efficiency is measured by the rate of CFM, or cubic feet per minute.

  • Low-exhaust equipment like ovens, steamers, and small kettles require an exhaust rate of 150 to 300 CFM per piece.
  • Medium-exhaust equipment like ranges, fryers, griddles, and large kettles require hoods exhaust flows of 150 to 400 CFM per piece.
  • High-exhaust equipment like charbroilers and wok ranges require minimum exhaust flow rates of 200 to 600 CFM each. Solid-fuel equipment, like charcoal- and wood-burning charbroilers, always require high-exhaust hoods.

Equipment Dimensions

Measure your equipment to determine the exact dimensions of the area you need to cover. This is important to ensure the vent hood is the proper size to manage the amount of exhaust your equipment produces. A hood that is too small will not be able to handle the volume of exhaust produced, and a hood that is too large can increase your energy costs by running a larger motor than necessary. According to the International Mechanical Code regulations, all hoods must overhang at least 6 inches beyond the edge of the cooking surface, though professionals recommend 12 inches at the front of the cookline, as extended overhangs increase the volume of capture and absorption.1

The height of the ceiling will also be a determining factor, as ceilings less than 8 feet, 6 inches in height require a special sloped-front hood or a low-proximity backshelf hood.

Type I and Type II Hoods

Depending on what types of kitchen equipment your facility uses, you will need to choose between type I and type II hoods, which perform distinct functions for different types of equipment.

  • Type I hoods, often referred to as grease hoods, are designed to remove grease and smoke particles from the air. They employ baffle-style hood filters to help capture grease, and are installed above equipment that produces grease-laden vapors, such as grills, deep fryers, and cooktops.
  • Type II hoods, often called condensate hoods, mitigate heat, moisture, and odor from the air. These hoods are commonly installed over dishwashers, though may also be used to remove steam produced by small equipment like toasters, pasta, rice, or hot dog cookers, or steam tables.

Styles of CaptiveAire Hoods

Make note of the location of each appliance. The style of hood to best fit your needs will be determined by how the kitchen space is utilized and how the equipment is arranged. Below is a brief overview of the styles of CaptiveAire hoods that are available for your customized system.

  • Wall canopy hoods are mounted to the wall behind cooking equipment. Their ease of installation and the fact most cooklines are installed against a wall make these the most common units.
  • Island hoods, offered in both single and double models, are installed from the ceiling to hang above equipment islands positioned away from walls.
  • Backshelf hoods, also called low proximity hoods, are designed for use with counter-height cooking equipment and have lower clearances from the equipment.

Determine the Rooftop Equipment

Answer the following questions to determine what type of rooftop equipment, such as exhaust fans and ductwork, your building will require, along with how and where those pieces should be installed.

  1. How many stories does your building have?
  2. Is your building's roof flat or pitched? The roofing angle affects the construction of the curb, the metal box the fan sits on where the ductwork terminates.
  3. What is the roof's material: rubber, shingle, or standing seam metal? If the roof is constructed of standing seam metal, the curb must be custom constructed, increasing the price of the system. Otherwise, the curb is standard and will only be affected by the roof's pitch.
  4. Consider whether the fan should be roof-mounted, wall-mounted, or inline. A roof-mounted fan is usually the go-to option, if there is enough roof space available and the ductwork leading to the fan will not be too long or complex. Wall-mounted fans are a good option if getting to the roof is difficult, such as when ductwork obstructions are present or in a multi-tenant high-rise building. Inline fans are mounted indoors and are typically the last option in circumstances that prevent roof-mounted or wall-mounted fans from being feasible.
  5. Does your system need tempered make-up air? Make-up air is almost always necessary in a proper kitchen design due to the load that an exhaust hood can put on the building's HVAC system. Depending on your location, a make-up air unit may be required by local codes and regulations. Dedicated make-up air is beneficial because it improves building balance, reduces HVAC costs, and improves hood performance. Tempered make-up air is heated and/or cooled, bringing the make-up air into the optimal temperature range for capture by the exhaust hood. In addition to further reducing the HVAC loads and improving staff comfort, some states mandate that food establishments have heated make-up air, so check your local regulations.2
  6. Is your building's electrical service single phase or three phase?
  7. Choose the electrical voltage: 120, 208, 230, or 460.
  8. Determine the length of exhaust duct work, including the number of 45- and 90-degree turns. CaptiveAire specializes in factory-welded ductwork, which provides several benefits over its field-welded counterpart, including:
    • Reduced risk of fire spreading outside the duct due to factory dye-testing, which ensures there are no leaks;
    • Easy installation can save time and money for the contractors who would normally be welding ductwork;
    • Ductwork comes with a UL listing.
    Within factory-welded ductwork, there are two subtypes: double-wall and single-wall. Double-wall is ductwork that has insulation already packaged within the ductwork, and gives reduced clearance or zero clearance to combustibles. Single-wall does not have any insulation. Welded ducts are also available for locations where those are needed.

Choose Your Fire System

CaptiveAire offers several fire suppression system options to ensure your facility is protected and prepared.

  • Ansul R-102 uses a chemical called potassium acetate to smother the fire, along with a vapor to prevent the flames from re-flashing after the fire has been extinguished.
  • Ansul Piranha uses a chemical called PRX to extinguish fires, followed by water to cool the area and continue the chemical reaction.
  • CORE uses electronic sensors to activate the system, pulling water from the building's water supply and mixing it with surfactant to extinguish grease fires.

During the customization process, you will decide where you want the fire system control panel to be accessible. The utility cabinet can be attached to the right or left side of the hood, or mounted to a nearby wall.

SpecBuilder

For customer convenience, CaptiveAire also features a program called SpecBuilder, a new web-based specifying software designed to walk customers through the process of creating the perfect customized ventilation system with just a few clicks of the mouse. Users are given the option to start the customization process by logging in or making a new user account, creating a project, and accessing the “tool box,” a space dedicated to cataloging charts, helpful content, and FAQs.

Check your local fire codes, safety protocols, and insurance regulations to ensure you order a CaptiveAire kitchen ventilation system that will meet all necessary requirements.

Once you have a CaptiveAire hood and commercial kitchen ventilation system installed in your facility, don't forget to perform routine maintenance and regular cleanings to ensure your system operates smoothly.

  • IMC Requirements. The Village of Homewood. Accessed October 2017.
  • Food Establishment Plan Review Manual. State of Michigan. Accessed October 2017.