Retrofit single attic bathroom exhaust fan to replace two combo fans


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Old 11-21-18, 05:47 AM
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Retrofit single attic bathroom exhaust fan to replace two combo fans

We have a shower adjacent to toilet room.
  • Shower and toilet room each have a cheap light/fan combo controlled by separate switches (each has it's own light switch and separate mechanical timer switch).
  • Both fans vent to the unfinished attic.
What I would like to do is:
  • Install a Fantech PB270-2 fan (or similar) to replace both combo fans.
  • Leave both current fan/light combos in place but bypass the combo fan itself.
  • Attach the new fan to the exhaust end of the existing 4" ducts via the included duct combiner.
  • Power on the new fan from either (both) mechanical timer switch(es).
Note that the Fantech comes with it's own grills that would not be used in this install.

This first post is to ask whether this could be easily done by a DIYer and/or if there is a better way to accomplish this? Also, what considerations I need to keep in mind regarding the existing install and re-wiring.

If it matters, I live in South Carolina and the existing fan/light combos were installed as part of new construction in 2009.

Thanks.
 

Last edited by XSleeper; 11-21-18 at 06:12 AM. Reason: Replaced / used synonym
  #2  
Old 11-21-18, 07:46 AM
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The only tricky part is wiring the switches. You could do it by converting the two existing switches to three ways. That would require pulling new wire in the walls though as a three way system requires an extra conductor. I have no idea if they even make three way timers though.
 
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Old 11-21-18, 08:18 AM
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Why the single fan vs just replacing the old fans with higher output?
 
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Old 11-21-18, 10:07 AM
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@Pilot Dane: If the solution involves pulling new wires, then it's beyond what I'm willing to tackle. If that is what would be required, then I'd likely just wire the fan to one of the original connections and put a cover plate over the second and be done with it.

@Marq1: I was hoping to reduce the noise of the current setup somewhat by moving the fan into the attic and also increase the output as well. Also, this solution seems (from my limited research) to be cheaper than buying two fans. However, I am not married to the idea if there are ANY better suggestions, I'm all for it...including suggestions for fans.

Thanks for the responses!
 
 

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