Appropriate, safe, weather-tight, pest-resistant and effective intake fittings with unrestricted air flow
Specifications
- SF
- MH
- MF
Specification | Objective |
---|---|
Select intake fitting: that is appropriate for regional weather conditions and installation location with an integrated collar at least the same diameter as the exhaust duct outlet with an integrated pest screen with holes no less than 1/4" and no greater than 1/2" in very cold climates that have no backflow dampers or use backflow dampers that resist freezing |
Appropriate, safe, and weather resistant termination |
- SF
- MH
- MF
Specification | Objective |
---|---|
Damper must open in the direction of the desired flow Damper will close when system is off No damper is required if the system operates continuously |
Prevent unwanted air movement while not restricting desired air flow |
- SF
- MH
- MF
Specification | Objective |
---|---|
Install intake to pull air from the outdoors, which does not include unconditioned spaces such as attics and crawl spaces that are ventilated with the outdoors Install intake: 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 |
Unrestricted entry of contaminant-free air |
- SF
- MH
- MF
Specification | Objective |
---|---|
Cut hole no larger than a 1/4" greater than the termination fitting Weather seal and flash the exterior fitting Mechanically fasten termination in place following manufacturer specifications Do not inhibit damper operation if included in termination |
Weather-resistant, durable, and effective installation |
- SF
- MH
- MF
Specification | Objective |
---|---|
If termination collar is larger than intake duct install a rigid metal transition |
Effective termination connection |
- SF
- MH
- MF
Specification | Objective |
---|---|
Label intake fitting: "ventilation air intake" |
Prevent fitting restriction |
- SF
- MH
- MF
Specification | Objective |
---|---|
Seal all duct connections with UL 181B or 181B-M listed materials (e.g., mastic, tape) |
Airtight duct connections |