Inline and Multiport Fans

Select a fan that:

has an electrically commutated motor (ECM)

has an efficacy of 3.8 cfm/watt or more

Select sealants that:

are compatible with their intended surfaces,

allow for differential expansion and contraction between dissimilar materials,

meet the requirements of the applicable fire safety code (e.g., thermal or ignition barriers), and

for use inside the pressure boundary select low volatile organic compound (VOC) sealants that meet independent testing and verification protocols

Install all electrical wiring according to manufacturer specifications and applicable code

Orient the fan outlet toward the final termination location and so the equivalent length of the duct run is as short as possible

Mount fan using mechanical fasteners and per manufacturer's specifications so that fan housing does not shake, rattle, or vibrate when operating

If the fan does not contain an integrated damper, install a damper that:

opens in the direction of the desired flow

closes when the system is off

Cut hole for intakes leaving no more than a 1/8" gap on each side

Install register boots using mechanical fasteners sufficient to prevent movement

Seal gaps around intake register boots with compatible sealant

Ensure fan and service disconnect switch are accessible for maintenance according to NEC, or applicable building code

Duct and terminate fan to the outdoors, which does not include unconditioned spaces such as attics and crawl spaces that are ventilated with the outdoors, in accordance with SWS detail for "Ventilation Ducts"