Stale room air is sucked into the exhaust grille(s). The integral backdraft damper allows air to flow out, but prevents cold (or hot) outdoor air from flowing backwards when the fan is off. A PBH (halogen) or PBL (LED) combination grille and light may be used instead of the standard grille. The PBH/PBL are UL listed for wet applications (work great in a shower area!), and provide great localized light. The lights can be controlled from the same switch as the fan, but is usually separated and controlled with the other lights in the bathroom.
Flexible, insulated ductwork is used to connect the grilles to the fan, installed in the attic. A larger fan can serve 2 or more bathrooms by connecting the exhaust ducts with a "Y" fitting.
We highly recommend flexible, insulated, duct for exhaust fans. This duct is easy to install, provides great acoustics, and since it is insulated minimizes condensation.
3 of the most popular choices for a discharge port (exhaust air exit from the house) are roof caps, sidewall vents, or soffit vents.
For fan sizing information please see our other "How To's" or use the bathroom system builder/calculator.
Additional Notes and Tips:
- suggested maximum airflow for Fantech exhaust grills is: 4" - 100CFM, 5" - 125 CFM, 6" - 150 CFM, 8" - 200 CFM
- use flexible insulating ducting to limit noise and condensation
- use 8 feet or more of the insulated ductwork between the grille and the fan to maximize acustical benefits
- make sure that you hang the duct so that no valleys are created -- condensation can pool in the valleys, potentially blocking the air flow
- always use a backdraft damper to prevent drafts
- Fantech fans are fully speed controllable
- Fantech Speed Controls and Timers
- Fantech Flexible Insulated Duct
- All Fantech Products
As always, if you would like to ask more questions about this or other technical topics give us a call at 877-711-4822 - 9-5 PST. Live people for technical and sales support - an Internet first!
Pictures and images courtesy of Fantech.