6.6102.2 Intakes

Topic: 
Supply
Subtopic: 
Components
Desired Outcome: 
Intake optimizes air flow while limiting the entry of insects, debris, and contaminants
TitleSpecification(s)Objective(s)
6.6102.2a
Hole in building shell

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

Ensure a weather tight installation

6.6102.2b
Intake fitting

Collar will be at least the same diameter as the duct; if collar is larger than duct, 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 draw the required volume of air from the outdoors

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

6.6102.2c
Occupant education

Intake fitting will be labeled "ventilation air intake"

Occupant will be instructed to keep yard debris and other contaminants clear of the intake

Ensure unrestricted air flow

6.6102.2d
Damper (if applicable)

The damper will be installed to open in the direction of the desired flow

Damper will close when system is off

Ensure unrestricted air flow

6.6102.2e
Connection to intake fitting

Duct to intake fitting will be connected and sealed 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
  • Flexible duct between 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 and end of metal or PVC duct will be screwed into place
  • 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

Ensure fasteners do not inhibit intake damper operation

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 intake installation

Ensure unrestricted air flow

6.6102.2f
Weatherproofing

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 intake installation

Ensure unrestricted air flow

6.6102.2g
Pest exclusion

Corrosion resistant screen, louver, or grille material no less than ¼" and no greater than ½" hole size in any direction will be used, or as specified by authority having jurisdiction

Screen will be installed so it does not inhibit intake damper operation

Prevent pest entry

Ensure unrestricted air flow

6.6102.2h
Intake location

Intake will be installed according to the following:

  • A minimum of 6" from grade
  • A minimum of 10' from contaminant sources or exhaust outlets
  • Above local snow or flood line
  • A minimum of 18" above an asphalt based roof
  • Never on a flat roof
  • As required by authority having jurisdiction

Prevent contaminants from entering house

Ensure unrestricted air flow