6.6003.3 Through the Wall

Topic: 
Exhaust
Subtopic: 
Fans
Desired Outcome: 
Through the wall fans installed to specification
Note: 
The authority having jurisdiction may require that a licensed professional perform certain tasks outlined in this detail.
TitleSpecification(s)Objective(s)
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