HVI's Fresh Ideas Home Ventilation & Indoor Air Quality Guide Articles

Inline Fans

Inline fans present an attractive option for homeowners who want to locate the fan away from the room or rooms that need exhausting.

Inline fans are mounted inline with the ductwork, bringing air from the inside and to the outside of the home. An inline fan may also be described as a remote-mounted fan.

Inline fans are useful for applications that include:

  • Ventilation of wet spaces such as bathrooms, kitchens and laundries
  • Remote fans for kitchen range hoods
  • Duct boosters for ventilation systems and clothes dryers
  • Supply or exhaust fans for continuous whole-house ventilation
  • Radon mitigation systems.

Inline fans come in many different configurations, sizes and capabilities to meet a wide variety of ventilation needs. They are available as simple single-port versions or versatile multiport versions. Single-port units have one incoming supply duct and one outgoing exhaust duct. Multiport versions have multiple ducts with a minimum of one inlet and one exhaust. A single fan can then manage air movement to or from multiple locations (e.g., two bathrooms). By varying duct sizes, inserting “Y” fittings to branch duct runs, employing adjustable grille openings and varying the fan speeds, different ventilation rates are possible for each location connected. Multiport versions offer ventilation capacity appropriate for larger-scale single family, multifamily and commercial buildings.

Inline fans are available in a range of airflow capacities from about 100 CFM, suitable for many housing needs, to 2,000 CFM for commercial applications. Manufacturers offer a variety of sizes, flow capacities, ducting configurations, controls and accessories.


By closing this banner, scrolling this page, clicking a link or otherwise continuing to use our site, you acknowledge that you accept our Terms of Use.