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Why Use An Inline Fan for Bathroom Ventilation?

When replacing an old, noisy, ineffective bathroom fan - there are many options.  It is possible to replace a traditional ceiling-mount bathroom fan with a new fan just like it.  OR - you can replace the old fan with an inline fan system.


An inline fan does not rest directly on the ceiling of the bathroom.  Rather - the fan installs in the attic space above or slightly away from the bathroom.  An inline fan has several advantages over a traditional bathroom fan:

* POWER - because the fan can be mounted anywhere in the attic - the power of the fan is not limited by the space where it is installed
* SOUND - because the fan can be mounted many feet away from exhaust point on the ceiling - fan vibration and noise is kept to a minimum.  The insulated ductwork used in an attic will protect from condensation and provides an excellent sound dampener
* MULTIPLE EXHAUST POINTS - in a larger bathroom, it is possible to create mutiple exhaust points in the ceiling and only install 1 fan.  This is done with a WYE connector, some flexible ductwork, and multiple grilles.  Grilles are available in many shapes and sizes, and can also be purchased with lights.


So, what do you need to create a bathroom ventilation system with an inline fan?

1). FAN - Obviously, you need the fan itself.  We stock and sell inline fans from Fantech, Suncourt, and Panasonic.   The fan that you purchase will depend on the size of the bathroom you are ventilating.  Click here for a fan sizing guide.  All fans must exhaust to the outside - so it's important to consider the diameter of the ductwork running to the roof cap, wall cap, or soffit vent before choosing a fan.  It is not advisable to reduce the diameter of your duct run - so if you install a powerful fan - you may have to install a new wall cap, roof cap, or soffit vent.

2). INTERIOR GRILLE - You will need a interior grille of some sort  to serve as your ventilation exhaust point.  Grilles come in many shapes, sizes, and styles.  As with the exterior vent, you will have to match the diameter of your ductwork with the size of the duct collar on the grille.  The grille may or may not include a integrated backdraft damper to keep air from entering the bathroom from outdoors.  It is possible that the exterior grille will include a flap, set of louvers, or damper.  The best bet is to include a fantech spring-loaded backdraft damper somewhere in the system.

3).  DUCTWORK - You will need to connect the interior grille, the fan, and the exterior vent with ductwork.   Rigid, metal ductwork offers the least amout of resistance to airflow, while insulated flexible ductwork is easy to work with and has sound-reducing characteristics.  Regardless of the type of ductwork you use - if you are running through an attic space - make sure it is insulated to prevent condensation problems.

4).  EXTERIOR VENT - all bath fans MUST exhaust to the outdoors.  It is possible to vent your ducting through a wall, roof, or soffit.  It is best to make your ducting a straight and short as possible.  We offer roof caps, wall caps/louvers, and soffit vents. 

4).  SWITCH - it's a good idea to put your bath fan on a timer.  This way - the fan will turn itself off if you forget.  An inline fan system is generally quieter than a ceiling mount fan and you might forget that it's on.