by Russell L. Bean, CFSP

In "Venting in the kitchen" (read it here!) in the August 2010 issue of Chef Magazine, we discuss the latest in kitchen ventilation technology, from green Type I hoods to ventless systems to ultraviolet light solutions. To prepare you for speaking with your ventilation system specialist, Chef has pulled together a ventilation jargon and acronym guide.

Type I Hoods
Designed to capture heat and moisture, plus smoke and grease, these hoods are typically required for frying, broiling and griddle cooking operations. These hoods must have water-tight construction and a built-in fire suppression system.

Type II Hoods
Designed to capture heat and moisture, they also can be used for dishwashing and some baking and steam equipment.

Unlisted Hoods
Unlisted hoods must meet the materials, design and exhaust rate requirements of local building and health codes.

Listed Hoods
Listed hoods are tested to meet a recognized standard, such as Underwriters Laboratories (UL) Standard 710, which specifies construction materials, design requirements and capture performance.

Ventless Hoods/Systems
These are smaller hood systems that capture then clean air using multiple filters, before exhausting the "clean" air back into the kitchen.

Proximity Hoods
As the name implies, these are back-shelf, pass-over and eyebrow-style hoods that are positioned just above the cooking equipment.

UV Systems
These are hoods that use ultraviolet light to convert--or reduce the size of--a significant portion of grease particulate into carbon dioxide and water.

Side Panels
Full and partial side panels are designed to help capture and contain effluents at the end of a hood.

Plenum
This is a transitional sheet-metal fabrication that connects the hood to the exhaust duct.

Effluents
Effluents are a commonly used collective for all cooking process byproducts including heat, moisture, combustion gases, smoke, grease and odors.

Capture and Containment
The goal of all hood systems, to "capture" 100 percent of all effluents produced by cooking processes, plus waste heat and humidity; and "contain" these cooking byproducts until they are either exhausted to the building exterior or filtered and returned to the kitchen.

Makeup (Supply, Replacement) Air
This is the fresh air brought in to replace air consumed by gas burner combustion or exhausted by the ventilation system. Air removed by an exhaust hood must be replaced by an equal volume of replacement air.

Microns
Effluent particulate is typically measured in microns, a unit of measure that is one-millionth of a meter, or .000001 m.

CFMs
Short for cubic feet per minute, CFMs are a measure of the air volume removed from a kitchen by an exhaust hood and venting system, and/or the volume of makeup air added or returned to the kitchen.

FPM
Short for feet per minute, this is a measurement of the speed of air moving through an exhaust system or part thereof.