Replies

1. 
   mk10 | Sep 23, 2021 10:53pm | #1

   Anyone have any info on this? Thanks!

2. 
   Malcolm_Taylor | Sep 23, 2021 11:58pm | #2

   Mark,

   There is no reason to have poly on the interior walls of the bathroom. You can take it out.

1. 
   mk10 | Sep 24, 2021 07:38am | #3

   Thanks for the reply, so confusing I did some more searching before your response and found (i think on this site and on some insulation company sites ) that in the bath the interior should have a vapor barrier on the inside to keep out as much moisture as possible from entering the wall cavity

1. 
   Malcolm_Taylor | Sep 24, 2021 12:05pm | #5

   Mark,

   If you have enough moisture in the bathroom that it can enter and cause damage to the interior bathroom walls you need to deal with that by adequate ventilation, not vapour-barriers.

   That's a different issue from providing a good vapour-barrier on the insulated exterior walls, where it is definitely necessary.

1. 
   mk10 | Sep 27, 2021 08:21am | #6

   Thanks for the reply, this makes total sense now I get it! I do have a ventilation fan in the wall as I have a cathedral ceiling and i don’t think at this point I could put one in the ceiling.

   I actually had the one in the wall plugged for the past ten years but will use it now. I would like to upgrade as I don’t think it works well enough but it has this auto open door on it and can seem to find a replacement or way to upgrade the fan without a complete replacement, any recommendations would be appreciated.

1. 
   user-2310254 | Sep 27, 2021 09:11am | #8

   Something like this? https://na.panasonic.com/us/home-and-building-solutions/ventilation-indoor-air-quality/ventilation-fans/whisperwalltm-thru-wall-ventilation-70-cfm

2. 
   Malcolm_Taylor | Sep 27, 2021 10:59am | #9

   Mark,

   The big advantage of most Panasonic fans, like the one Steve linked to, is they are quiet, and that makes them much more likely to get used. Replacing the switch with timer helps too.

3. 
   mk10 | Sep 27, 2021 11:38am | #10

   Thanks, i definitely want to replace it. This fan has an integrated auto open/close vent which appears to seal very well, i would like to keep that part installed but can’t find a fan that will work with it. If you look in the upper right of the picture you will see the motor for the vent.

   Added pic of outside wall cap that is motorized

   
4. 
   Malcolm_Taylor | Sep 27, 2021 12:42pm | #11

   Mark,

   Finding appropriate upgrades to fit in existing fan housings is a real problem. I've started putting the whole thing in a larger air-sealed plywood box so that the housing and all the fittings are accessible and can be replaced. Not much help in your situation though...

3. 
   user-2310254 | Sep 24, 2021 11:46am | #4

   Mark,

   You don't want moisture infiltrating into the walls and then condensing on the back side of the drywall or the exterior sheathing. This article may be helpful: https://www.finehomebuilding.com/project-guides/drywall/airtight-drywall.

   It's also important to have a high-quality bath fan that vents to the outside.

1. 
   mk10 | Sep 27, 2021 08:23am | #7

   Thanks for the link and the info, makes more sense now. See bath fan comment #6

4. 
   mk10 | Sep 27, 2021 03:39pm | #12

   Can’t seem to reply to some of the responses, the “reply” is missing.

   Steve, i did see that one looks like it could work (it’s expensive!) i really would like to keep the motorized wall cap but appears to be integrated into the fan And I can’t find anything like it.

   I guess my concern is how much cold air will come in or does a regular non motorized damper work well.

1. 
   user-2310254 | Sep 27, 2021 04:12pm | #13

   Maybe this will work: https://www.amazon.com/ALDES-Spring-Loaded-Backdraft-Damper/dp/B002FWR40K/ref=sr_1_8?dchild=1&keywords=exhaust+fan+damper&qid=1632773286&sr=8-8

   You could always try Panasonic technical support as well. Many of the in-ceiling fans has a built-in damper, but I don't see one in the through-wall unit.

5. 
   bob_swinburne | Sep 27, 2021 06:19pm | #14

   80’s and 90’s Vermont - they were using plastic in exterior walls. ‘68 is a bit early. They probably thought it would be extra insurance. My bath fan works very well but draws cold air in under the door so it doesn’t get used much during showers. Wonder about a single unit heat exchange like the eGo by fourSevenFive ? I think Broan might make one too.