6.6002.2 Terminations

Topic: 
Exhaust
Subtopic: 
Components
Desired Outcome: 
Securely installed termination fittings with unrestricted air flow
TitleSpecification(s)Objective(s)
6.6002.2a
Hole in building shell

A hole no greater than a 1/4" greater than the fitting will be cut to accommodate termination fitting

Allow for ease of weatherproofing

6.6002.2b
Termination fitting

A termination fitting with an integrated collar will be used

Collar will be at least the same diameter as the exhaust fan outlet; if collar is larger than exhaust fan outlet, a rigid metal transition will be used

Fitting will be appropriate for regional weather conditions and installation location on house so as not to be rendered inoperable

Effectively move the required volume of air to the outside

Preserve integrity of the building envelope Envelope The separation between the interior and exterior environments of a building that includes a combination of air and thermal barrier

Ensure durable installation

6.6002.2c
Duct to termination connection

Duct will be connected and sealed to termination fitting as follows:

  • Round metal-to-metal or metal-to-PVC will be fastened with a minimum of three equally spaced screws
  • Other metal-to-metal or metal-to-PVC connections will be securely fastened and sealed with welds, gaskets, mastics (adhesives), mastic-plus-embedded-fabric systems, or tapes
  • Flexible duct-to-metal or flexible duct-to-PVC will be fastened with tie bands using a tie band Tie band A strap, often made of nylon, that mechanically squeezes a flexible duct to a fitting. Must have a minimum performance temperature rating of 165° (per UL 181A-type test) and a minimum tensile strength rating of 50 pounds tensioning tool
  • PVC-to-PVC materials will be fastened with approved PVC cement
  • Other specialized duct fittings will be fastened in accordance with manufacturer specifications
  • In addition to mechanical fasteners, duct connections will be sealed with UL UL Underwriters Laboratories 181B or 181B-M listed material

Fasteners will not inhibit damper operation

Effectively move the required volume of air to the outside

Preserve integrity of the building envelope Envelope The separation between the interior and exterior environments of a building that includes a combination of air and thermal barrier

Ensure durable installation

6.6002.2d
Weatherproof installation

Exterior termination fitting will be flashed or weather sealed

Water will be directed away from penetration

Installation will not inhibit damper operation

Manufacturer specifications will be followed

Preserve integrity of the building envelope Envelope The separation between the interior and exterior environments of a building that includes a combination of air and thermal barrier

Ensure a weather tight and durable termination installation

Ensure unrestricted air flow

6.6002.2e
Pest exclusion

Screen material with no less than ¼" and no greater than ½" hole size in any direction will be used

Installation will not inhibit damper operation or restrict air flow

Prevent pest entry

Ensure proper air flow

6.6002.2f
Termination location

Terminations will be ducted to the outdoors, which does not include unconditioned spaces such as attics and crawl spaces that are ventilated with the outdoors.

Terminations will be installed:

  • A minimum of 3' away from any property line
  • A minimum of 3' away from operable opening to houses
  • A minimum of 10' away from mechanical intake
  • As required by authority having jurisdiction

Prevent exhaust from reentering house

6.6002.2g
Kitchen exhaust

Galvanized steel, stainless steel, or copper will be used for termination fitting for kitchen exhaust

Prevent a fire hazard