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How can you have balancing dampers in a grease duct? I thought they were not allowed?

Here’s what NFPA 96 has to say about balancing dampers in commercial kitchen exhaust ducts. Chapter 9 Auxiliary Equipment 9.1 Dampers. 9.1.1 Dampers shall not be installed in exhaust ducts or exhaust duct systems. 9.1.2 Where specifically listed for such use or where required as part of a listed device or system, dampers in exhaust […]

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Demand Control Ventilation for Commercial Kitchens

Demand Control Ventilation Systems for Commercial Kitchens, how do they differ, how are they the same?

The number and type of Demand Control Ventilation (DCV) systems for commercial kitchens have grown significantly in recent years. This can be attributed to several factors, principally the adherence to ASHRAE 90.1 ventilation standard. This is the standard that affects design for commercial kitchens, and it states that on exhaust systems greater than 5000 cfm, […]

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Make-Up Air 101

How not to ruin a good thing, Make-up Air 101

Hey, it’s your birthday!  Go ahead and inhale those candles out!  What?  You don’t suck the flame off the candle?  Have you ever tried? Yes, it’s a silly anecdote and a very effective one (thanks, Dr. Livchak!).  As most of us know, we blow out our candles.  The physics works well and accomplishes the job […]

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Mechanical Engineers on CKV projects

Why is it important to know who the ME (Mechanical Engineer) on the project is?

As commercial kitchen ventilation systems become more technically complex to satisfy increasingly strict code requirements and environmental standards, coordinating the overall design with the mechanical engineer becomes critical. There was a time when the foodservice consultant whose scope is traditionally below the kitchen ceiling and the mechanical engineer whose interest is above the ceiling worked […]

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Commercial Kitchen Pollution Control Units - PCU

Love Thy Neighbor: Pollution Control for Commercial Kitchens

If you are involved with the design or building of food service properties, then you have probably heard of Pollution Control Systems or Commercial Kitchen Pollution Control Units, or PCU’s for short. A PCU is a system of special filters to help clean grease, smoke and odors from the exhaust air stream of commercial kitchens […]

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Pollution Control Unit

What is the difference between commercial kitchen pollution control units?

Commercial Kitchen Pollution Control Units, also referred to as Scrubbers or Ecology units are systems that remove a high percentage of grease, vapor, and odors from the cooking process through a means of filtration. The devices fall into 2 major categories, media filter type and electrostatic precipitators (ESP). These systems have a form of odor […]

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Heat Gain to Space

How heat sources differ in commercial kitchens than other commercial spaces

Mechanical engineers calculate cooling and heating loads for commercial spaces in order to size the ventilation systems. The type of space plays a key role in determining necessary ventilation requirements. Commercial kitchens are unique in they operate year round and cooling is almost always required, even during the colder winter months. This is due to […]

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Gas burning in the burner of gas oven

Why is a heat load based design important for kitchen hoods?

Establishing exhaust volumes for hoods had been an inexact science, primarily relying on U.L. values to establish exhaust rates. U.L. however clearly states that the minimum exhaust rates established during testing should not be used for design purposes since they were achieved in a laboratory environment. A greater exhaust might be required to provide proper […]

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air ceiling registers

How do replacement air ceiling registers affect the hood?

The placement and location of ceiling registers (diffusers) for the introduction of replacement air can have a direct impact on the proper operation of the exhaust hood. Diffusers that have been designed for commercial spaces, such as “four way diffusers” were developed to have a high induction capability. That means they discharge at a relatively […]

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Kitchen Ventilation Commercial Cooking Equipment

Is cooking equipment makes and models important for preliminary engineering?

Commercial cooking equipment makes and models are important for preliminary engineering Outdated methods of ventilation design categorized commercial cooking equipment (appliances) into different classes; light, medium, heavy-duty and extra heavy duty (solid fuel). The average exhaust rates were established for each category based on rules of thumb, cfm per foot of hood. With the advent […]

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