Bathroom fan exhaust vent

[HillStreet]

You will find the majority not vented to the outside. I have yet to see an issue with it.

I don稚 know the weather in KC but up here we not only vent to the outside, but we insulate the duct too. I don稚 know how the wet, warm exhaust could dissipate into the attic, or between floors without leaving condensation. Warmer air will condense when it hits cooler air.

 

[jk96]

I don稚 know the weather in KC but up here we not only vent to the outside, but we insulate the duct too. I don稚 know how the wet, warm exhaust could dissipate into the attic, or between floors without leaving condensation. Warmer air will condense when it hits cooler air.

I'm not too far from the KC area and yes all fans should be vented to the outside of the home. As Eddie mentioned you will find a lot of homes not built recently that have venting into the attic. While not a good practice it is a lot more forgiving then the ops situation where his is vented between the floor joists. Since he has an outside vent that's not connected I think the earlier post had it correct in that the sheetrockers likely got ahead of the HVAC guys.

 

[Tomtint]

Always vent to the outside of the house. The fans are supposed to suck smell...and moisture from the room ( steam from the shower ) and simply dumping it into a space in the attic or betweenfloors..is a recipe for mold.

 

[Tractor Seabee]

If you can see daylight through the cavity should be easy to snake that aluminum flex pipe in there. Not sure how long you can get it but it's not hard to couple lengths together. connect it to the fan first. I would use an electricians pull snake to keep it moving to the exterior. As all have said, it is necessary to do. It is probably not if you will have problems but when. On a cold day here with the shower going there is a huge plume of water vapor coming from my vents. But I like hot showers and have large very quite fans. Quietest ones Lowe's sells.

Ron

 

[4570Man]

They’re supposed to be vented outside by code but I don’t think venting to the attic hurts anything. Venting between the floors seems like a bad idea.

 

[kcflhrc]

They’re supposed to be vented outside by code but I don’t think venting to the attic hurts anything. Venting between the floors seems like a bad idea.

That code would depend on where you live. It certainly isn't some National Code that's for sure. Although I agree that it would be best practice do vent outside, it's just not possible to do this on my 1970 2 story farm house. It's been vented between floor joists for all this time and I have replaced the fans and see no ill effects from this. No moisture, no mold, nothing.

 

[3Ts]

I found this and it goes back to the 2000 building code as well, probably farther. There is more info on size of exhaust pipe and distances, etc. in the building codes.


International Residential Code (IRC) 2012
Chapter 15 - Exhaust Systems
SECTION M1501 GENERAL
M1501.1 Outdoor discharge. The air removed by every mechanical exhaust system shall be discharged to the outdoors in accordance with Section M1506.2. Air shall not be exhausted into an attic, soffit, ridge vent or crawl space.

Exception: Whole-house ventilation-type attic fans that discharge into the attic space of dwelling units having private attics shall be permitted.

 

[EddieWalker]

What is a private attic?

 

[thekkfan]

What is a private attic?

One without rats, bats, or squirrels I guess. :laughing:

 

[outinthetalgrass]

One that is only over your house, as opposed to one that is open to both side of a duplex or several condos.