I was looking at a house and the bathrooms appear to have no exhaust fans. It does have these little things that look like they might be vents of some sort. Could they be sufficient for ventilation to remove moisture, with no apparent fans? The house is from the 80s. There are no windows in the bathrooms.


  • 2
    Bathrooms without windows have required vents for 50 years that I know of. Turn your 3 switches on and see if a piece of paper will stick to the vent, turn the switches off 1 at a time and notice what they do. 3 switches quite common , 1 light , 2 vent, 3 heat. If you have a central light heat unit the vent may be in that and not obvious. It never made sense to me to have a ceiling heat lamp with a exhaust fan in the same fixture , the fan itself may have seized not uncommon.
    – Ed Beal
    Feb 26 '20 at 19:28
  • It seems unlikely fans would have seized in all 3 bathrooms unless there is some kind of central fan that services all of them. I will check for air flow. I will also check if there is a switch with no apparent purpose in each bathroom. Thanks for the suggestions!
    – user35358
    Feb 26 '20 at 20:19
  • Since you only mention 1 bathroom we had no idea there were multiple bathrooms, if it is a common exhaust duct 1 fan that failed would make sense but not be practical. Please provide additional info including what the 3 switches are for.
    – Ed Beal
    Feb 26 '20 at 21:33
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    I have seen in a number of homes I helped build that had one central fan for the bathrooms and all baths ducted through the one fan. If there is one switch that appears to to nothing an all baths that may be what is going on and the one fan is faulty
    – Jack
    Feb 26 '20 at 21:42
  • Sorry I thought I had mentioned 3 bathrooms all the same. I suspect they do all have 1 switch with no apparent purpose, but I will double check when I go back.
    – user35358
    Feb 27 '20 at 4:15

Sure, could be an exhaust fan...but it could be a supply fan too.

To check, tape a piece of paper over about half the vent opening and wait for the fan to come on. Does it blow or suck?

Btw, look under the toe kick of the cabinet to see if there’s another vent.


That appears to be a standard air conditioning register. Code changes over the years may mean that the home wasn't required to have the vent fans when it was built.

  • Interesting. The house doesn't (currently) have A/C.
    – user35358
    Feb 26 '20 at 20:13
  • I have voted to close because of such low information , funny air conditioned space means heat/ cool or both. Even a swamp cooler is a type of conditioning. So if you want help answer the questions as there are 3 votes to close already.
    – Ed Beal
    Feb 26 '20 at 21:34
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    @user35358 It might just be an AC register added to the old vent duct to make it look better. Can you get up into the attic to see where the duct ends up?
    – JACK
    Feb 27 '20 at 0:48
  • Good idea, I will peek in the attic and see if I can follow it.
    – user35358
    Feb 27 '20 at 4:16

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