Vent-A-Hood® Range Hoods - Articles

Glossary of Ventilation Terms

To make the field of kitchen ventilation systems easier to understand we have compiled a list of common terms that you might hear while dealing with professionals from the ventilation industry or while installing a range hood in your house. Just knowing the language can simplify the entire procedure.


BTU - British Thermal Unit. BTU’s are used to measure the heat output of gas cooking appliances.

Canopy - The physical exterior portion of the hood. Also may be referred to as a “shell”. The purpose of a range hood canopy is to collect cooking vapors as they rise up from the cooking surface.

CFM - Cubic Feet of Air per Minute. A measurement of the volume of air that is flowing into or out of a space.

Duct or Ducting - Duct is attached to the top of a range hood and serves to exhaust cooking contaminants to the outside air. The duct should be attached to an appropriate wall louver or roof jack.

External Blower - A blower unit that is mounted outside of the home on the wall or roof. The range hood canopy will contain mesh or baffle filters to extract grease.

Grease - A sticky film, that can become rancid, turn into fungus, and attract insects. Over one gallon of grease per year is generated in the average American home.

Heat - Created when a range burner is turned on. The heat from a standard four burner cooktop cancels out the efforts of one ton air conditioning if it is not removed from the home.

Hazardous Gases - Gases that are generated as a by-product of ignited natural gas. Nitrogen Dioxide and Carbon Monoxide are of the most concern if not removed from the home.

Holding Capacity - The interior space of a canopy. Generally speaking, the more powerful the cooking equipment beneath it, the larger the holding capacity that is required.

Liner or Liner Insert - A specialized range hood that is designed specifically to fit inside of a wood hood or other enclosure.

Mounting Height - The height off the cooking surface. The range hood should be hung at the recommended mounting height to allow for appropriate capture of cooking vapors.

Odor - The smell that is created during cooking. Odors are clingy, acidic, and will fade and deteriorate fabrics if not removed from the home.

Overlap - Sizing the range hood to be wider than the cooking equipment. Whenever possible, the range hood should overlap the cooking surface by 3” on each end. For island hoods, this recommendation should be considered mandatory.

Projection - The depth of the range hood front to rear. The range hood should be deep enough to come out to the front edge of the front burner.

Remote Blower - See external blower.

Roof Jack - An external venting piece on a roof of the home that connects to the duct on the range hood.

Smoke - Airborne carbon particles mixed with sulfuric acid. Smoke is an irritant to the eyes and poisonous to houseplants if not removed from the home.

Steam - Vaporized water. Steam can act as a “carrier” for other cooking contaminants if not removed from the home.

Wall Louver - An external venting piece on a side wall of the home that connects to the duct on the range hood.

Watts - A measurement of the heat output of electric cooking appliances.