Our Do-It-Yourself Help Section

See Archive On The Right For More Articles!

Ventilating multiple bathrooms with a single fan.

You can certainly use a single Fantech fan to vent multiple bathrooms. The big advantage to doing this is to save money.

However... before you start planning, some things should be noted:
- When the fan goes on, all bathrooms are ventilated. If the fan is very large and one of the bathrooms is unoccupied most of the time, this could mean "wasting" conditioned air.
- If the bathrooms are far apart, the ducting and labor required to connect them could defeat the savings.

Our recommendation is to use multiple bathroom ventilation for the following cases:
- The bathrooms are adjacent to each other (keeps duct runs to a minimum).
- The bathroooms are used mostly at the same time (to minimize waste of conditioned air)

FR Series In-Line Fans From Fantech
FG Series In-Line Fans From Fantech
PB Series Kits (with FG metal cased fan)
hvac Article Archives hvac
hvac Radon Mitigation
hvac Starting a booster fan with a current switch
hvac Quiet Kitchen Ventilation
hvac Selecting correct fan for a bathroom
hvac Using an in-line FR series fan
hvac Ventilating multiple bathrooms with 1 fan
hvac Whole House Fans
hvac Dryer Booster Fans (Residential)
hvac Wiring: 1 fan and 2 FD 60EM timers
hvac Wiring: 1 fan serving 2 baths with 1 switch per bath
hvac Wiring: Generic 120V coil relays
hvac Server/Electronics Cooling
hvac ACT Pumps - Save Money, Water, and Energy
hvac ACT and Laing Instant Hot Water Systems
hvac Ductwork Sealing
hvac Duct Booster Fans
hvac Stego Wrap for Sealing Crawl Spaces
hvac hvac

    Typical 2 Bathroom Installation Using an FR Series Fan

How do you control this fan? One popular method is to use electronic timers in each bathroom. The Fantech timer model number is the FD60EM. This unit has settings for 10, 20, 30, and 60 minutes. The timers (you could also use plain light switches as an alternative) are wired so that the contacts are in "parallel". This means that if any one of the timers (or switches) is turned on the fan will be energized. What is nice about using the electronic timers is that you can be sure the bath is thoroughly ventilated, and there are no "accidentally" left on fans, which could potentially waste a lot of conditioned air.

If you are using PBH or PBL grilles (grilles with built in lights), the light is usually controlled by a separate light switch, or switched along with other bathroom light fixtures.

An additional option is to use the CVS series fan from Fantech. It is basically a "fan in a box" with 3 to 4 ports on the side. This fan is great for tight spots and/or when more than 2 venting points are required.

CVS Series Fans From Fantech

    Typical CVS Installation

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

More Links:
- 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.