Chimneys Vs. Vents

For the ordinary homeowner, it can be easy to think that a chimney is the same thing as a vent. Chimneys serve to carry the byproducts of combustion out of homes, but they are technically not vents. To help you understand the differences between chimneys and vents, Fireplace Service Company would like to explain these two terms by sharing with you some information from the International Code Council (ICC).



The biggest difference between a chimney and a vent is that chimneys are made to be able to vent all types of fuel: oil, gas, wood, and other solid fuels. Chimneys come in two types:

  • Masonry Chimneys

Constructed from brick or other masonry materials, masonry chimneys must be lined for safety reasons.

  • Class A Chimneys

Also known as factory-built or prefabricated chimneys, these chimneys come as a unit that must always be used together. Made from stainless steel or galvanized steel, class A chimneys are insulated to keep the outside of the chimney from getting excessively hot.


While chimneys are able to vent all types of fuel, vents can only be used with gas, oil, or bio-mass appliances and can never be used for a solid fuel like wood. Vents are available in several types:

  • Type B Vents

Factory-built double wall vent pipes made to only vent gas, type B vents are inexpensive and made with a galvanized exterior and an aluminum interior.

  • Type L Vents

Able to be used as vents or connectors, type L vents are made to vent oil, although they can also be used to vent bio-mass fuels such as pellets and corn.

  • Pellet Vents

Technically also type L vents, pellet vents must be installed through a house or be contained inside a chase. Their exteriors can be made from black or galvanized steel, and their interiors are always constructed from stainless steel.

To review, the basic difference between chimneys and vents has to do with the fuels they can handle. If you have a wood-burning fireplace, chimney, or stove, it must be installed to a chimney as vents cannot handle solid fuels. To learn more about the differences between chimneys and vents, contact Fireplace Service Company. We can answer any questions you may have.

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