Kitchen Exhaust Systems: Simple to Complex Ductwork Designs

Red bricks house showing kitchen hoods outside

Kitchen exhaust systems< can be as different as the kitchens they serve. Whether it’s a straight and vertical shot from stovetop to rooftop or there are multiple twists and turns involved in the ductwork, kitchen exhaust cleaners must be able to work with any system. As multipurpose facilities and mixed-use developments become increasingly popular, kitchen exhaust systems must adapt to a variety of buildings. Especially when it comes to multilevel structures, kitchen exhaust systems must wind through each level to get to the roof for proper ventilation. This can result in a very complicated system that has several changes in direction and stretches of horizontal ductwork. This poses an additional challenge for the vendor hired to clean the system. At Bare Metal Standard, we know kitchen exhaust systems in and out. Read more about what’s involved in a basic kitchen exhaust system as well as how they can become complicated.

What is a Kitchen Exhaust System?

The typical kitchen exhaust system includes three components:

  1. The Hood

  2. The Ductwork

  3. The Exhaust Fan

Kitchen exhaust systems are often called: the grates, vents, louvers, hoods, vent-a-hood, and filters. While each of these descriptions are different, they are all referring to the kitchen hood, which is typically the only portion of the system that is visible.

Kitchen exhaust hood in a commercial kitchen.The Hood is the most obvious and noticeable part of the kitchen exhaust system. The hood is located directly above the cooking equipment, hanging over the stove or fryer and above the cook’s head. The hood collects all the heat and incoming grease vapors being produced from the cooking equipment. Inside the hood, baffle-filters collect and filter the grease vapors before they enter the ductwork. This makes it so less grease finds its way into the ductwork and thus gets expelled into the air outside the building.


Ventilation ductwork in a kitchen exhaust system.The Ductwork connects the ventilation hood all the way up to the exhaust fan on the exterior of the building, most often on the roof. The layout of the ductwork depends on the building design. Some kitchen exhaust systems will have ductwork with only one vertical section that leads directly to the roof while other systems will have varying degrees of horizontal and vertical sections that twist and turn through several levels to get to the exterior exhaust fan. It is these more complex systems that we see a wide array of custom designs fit specifically for that facility. These systems are also the most challenging to clean and require specialized processes and cleaning solutions to properly degrease.


Rooftop exhaust fan for a kitchen exhaust system.The Exhaust Fan pulls the air out of the kitchen, through the ductwork and into the air outside the building. Exhaust fans come in various makes and models but all function to remove grease vapor and exhaust from the surfaces of the cooking equipment. The exhaust fan is usually found on the rooftop of the building but can also be placed on the side of a wall or inside a Pollution Control Unit (PSU). A PCU pulls even more grease and sometimes odor out of the exhaust air. PCU’s are generally found in city centers or metropolitan areas where the exhaust could potentially come into contact with nearby people passing by the building. 


Kitchen Exhaust System Designs

Simple and complex kitchen exhaust system designs.

The configuration of a kitchen exhaust system can be as easy as a standalone building with a directly vertical duct. Freestanding restaurants or other kinds of commercial kitchens where the building only contains one cooking operation will usually have this type of simple duct configuration. This is because standalone buildings are designed with the intent of installing a kitchen exhaust system. They know where the kitchen will be in the building blueprints and can plan the system design accordingly. When a building is only one story tall, the kitchen exhaust system will not require very much ductwork to connect the hood to the exhaust fan. Therefore, the duct chase and the bottom of the exhaust fan are only a few feet away.  All sections of this type of kitchen exhaust system can be easily seen and cleaned.

Other systems however will have more complicated runs of ductwork, advanced pollution control units, or even long chases of horizontal ductwork and stories of vertical ductwork. Kitchen exhaust systems in strip malls or in buildings where the system has been installed after the construction of the building itself may require special these modifications. Exhaust systems for large or multiple story locations may need complicated ductwork to effectively transport the grease and exhaust to the exterior of the building. For example, when you place a kitchen in the basement with exhaust fans on the roof, the only way to connect them would be with extensive stretches of vertical and possibly even horizontal ductwork. Service cleans such as these may take several hours or several shifts.

At Bare Metal Standard, we have 50 years of experience cleaning the most challenging kitchen exhaust systems while retaining our guarantee of cleaning 100% of your system. We never shy away from complex ductwork nor do we hang inaccessible tags in hard to reach areas. We understand that a truly safe kitchen exhaust system is a completely clean kitchen exhaust system. We never lower our standards of cleanliness and we never cut corners to make our job easier. That’s the Bare Metal Standard.