| 6.6003.3a
Hole in building shell | A hole no greater than a 1/4 inch greater than the assembly will be cut to accommodate fan assembly | Allow for ease of weatherproofing |
| 6.6003.3b
Wiring | Wiring will be installed in accordance with original equipment manufacturer specifications, and local and national electrical and mechanical codes | Prevent an electrical hazard |
| 6.6003.3c
Fan mounting | Fan outlet will be oriented toward the final termination location Fan will be oriented so the equivalent length of the duct run is as short as possible Fan will be mounted securely according to manufacturer specifications | Install mounting fan securely Ensure fan housing does not shake, rattle, or hum when operating |
| 6.6003.3d
Weatherproof installation | Exterior termination fitting will be flashed or weather sealed Water will be directed away from penetration Termination fitting 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 installation Ensure unrestricted air flow |
| 6.6003.3e
Backdraft damper
Backdraft damper
A damper that allows air to flow in only one direction
| A
backdraft damper
Backdraft damper
A damper that allows air to flow in only one direction
will be installed between the outlet side of the fan and the exterior | Prevent reverse air flow when the fan is off |
| 6.6003.3f
Fan housing seal | Sealants will be compatible with their intended surfaces Sealants will be continuous and meet fire barrier specifications | Prevent air leakage through fan housing Ensure a permanent seal to the building
air barrier
Air barrier
The separation between the interior and exterior environments of a building that slows air flow to the point that no smoke movement is visible at 50 pascals of pressure difference across the boundary
|
| 6.6003.3g
Fan to interior surface seal | Sealants will be compatible with their intended surfaces Sealants will be continuous and meet fire barrier specifications | Prevent air leakage around intake housing Prevent a fire hazard |
| 6.6003.3h
Insulation | All components outside of the thermal
envelope
Envelope
The separation between the interior and exterior environments of a building that includes a combination of air and thermal barrier
will be insulated to a minimum of R-8 or equivalent to local code Exception: If system operates continuously, fan housing need not be insulated | Preserve integrity of the duct system |
| 6.6003.3i
Air flow | Air flows in
CFM
CFM
Cubic feet per minute
will be measured and adjusted to meet the design requirements | Exhaust sufficient air from desired locations to outside |
| 6.6003.3j
Preventing air leakage caused by exhaust fans | Leakage to the house from other spaces will be prevented (e.g., garages, unconditioned crawl spaces, unconditioned attics) | Ensure occupant health and safety |
| 6.6003.3k
Combustion safety | Pressure effects caused by fans will be assessed and corrected when found outside of combustion safety standards Make-up air will be provided in accordance with the current version of
ASHRAE
ASHRAE
American Society of Heating, Refrigerating and Air-Conditioning Engineers, www.ashrae.org
62.2 and in compliance with the authority having jurisdiction. | Ensure safe operation of combustion appliances |
