Planning for Building Exhaust

October 30, 2015 by Chris Drake

Building exhaust has a large impact on exterior walls and floor plan, so it is important to understand the codes related to exhaust.

Most buildings require at least restroom exhaust, and frequently buildings require garage exhaust. Exhaust is also required in cooking, chemical storage, laundry, and other applications.

There are three major code considerations when designing exhaust systems:

  1. Exhaust air must discharge 10 feet above grade
  2. Exhaust air must discharge 10 feet from building openings
  3. Minimum exhaust rates must be met

Discharging air 10 feet about grade is usually not an issue, but becomes tricky for enclosed basement garages. Garage exhaust fans move a large volume of air, requiring large chases. These chases must route to the second floor of most buildings, taking away from occupiable area. Planning for a large garage exhaust chase in the early phases of a project will save time and money during permitting. Garage exhaust terminates to large louvers that must be coordinated with the building exterior.

In general, the requirement that exhaust air be discharged 10 feet from building openings affects the building exterior more than the interior. Depending on locations of operable windows and doors, exhaust may have to route to a prominent part of the building exterior. Keeping this in mind when designing fenestrations can help ensure that the feature exterior walls remain aesthetically pleasing.

Minimum exhaust rates are defined by code. These codes help ensure that odors and contaminants do not migrate throughout the building. The volume of required exhaust air will affect the size of the louvers and vents (see photos below).  The volume of required exhaust air will affect the size of the external penetrations. To ensure that the mechanical design does not negatively impact building exterior aesthetics, it may be favorable to bring exhaust air to the roof through chases, or locate rooms that require exhaust along less visible walls.

Planning space for duct chases and external penetrations is crucial to achieving a successful design. BRD designers understand that ductwork and external penetrations affect building image. Accordingly, we commonly collaborate with our architects to minimize or eliminate the impact on building appearance.

Your project needs Mechanical, Electrical, and Plumbing Engineers who have done this before. Our MEP team has completed the HVAC, electrical, and plumbing design for hundreds of apartments, office buildings, and related development projects. Contact us today to learn how we can help make your next project a success. 


Written by Chris Drake

Chris Drake

Chris Drake is the Plumbing Discipline Leader at BIG RED DOG. He received a degree in Aeronautical Engineering from Rensselaer Polytechnic Institute in Troy, NY and is a registered P.E. His professional experience includes the design of plumbing and HVAC systems in the campus, institutional, sports, federal, and manufacturing markets. His is also experienced in design/build, construction administration, and is a member of ASHRAE and ASPE. Chris originally hails from the Finger Lakes region of upstate New York. Outside of work, Chris enjoys exploring Austin and the surrounding hill country, traveling, and supporting the Buffalo Bills.