# dryer/bathroom vent terminations and window clearances



## itsnotrequired (Apr 30, 2010)

this issue came up in my basement finishing thread but figured i would ask specifically here.

i am replacing a small 1'x2' basement window with a much larger 6'x4'. issue is that the two vents in the picture below will be above the window.









dryer vent is on the left, bathroom vent is on the right. dryer vent is for an electric dryer, bathroom vent is actually a broan multi-port ventilator handling the two bathrooms in the house.

taking a look at the irc:



> SECTION M1502 CLOTHES DRYER EXHAUST
> *
> M1502.3 Duct termination.*
> Exhaust ducts shall terminate on the outside of the building. Exhaust duct terminations shall be in accordance with the dryer manufacturer’s installation instructions. If the manufacturer’s instructions do not specify a termination location, the exhaust duct shall terminate not less than 3 feet (914 mm) in any direction from openings into buildings. Exhaust duct terminations shall be equipped with a backdraft damper. Screens shall not be installed at the duct termination.


the installation instructions for my dryer simply indicate that the vent termination should be 12" above grade and 12" away from obstructions (large rocks, bushes, etc.) does this simple manufacturer instruction meet the criteria of a 'specified termination location'? i would argue yes but i am not a code expert. if it is an issue, i think i could make a case with the inspector:


exhaust is within 3' of the existing window. home is about 10 years old and looking back at old versions of the irc, it looks like clothes dryer vent termination location wasn't addressed until 2006 so maybe it wasn't an issue back them. also looks like 2006 version dictated the vent must be a minimum 3' away from opening, regardless of manufacturer direction yet in 2009, this was changed such that the 3' clearance was only required if the manufacturer gives no direction.
dryer is electric so i am only venting moist air, not any combustion gases.
right now, vent run is a 90 down out of the dryer, a 90 in the basement to horizontal and then a straight shot out of the house. rerouting of the vent would result in additional 90s and thus a greater chance of lint accumulation and therefore an increased fire risk. that doesn't seem like a good idea.
i'm more worried about the bathroom exhaust.



> SECTION M1506 EXHAUST DUCTS AND EXHAUST OPENINGS
> 
> *M1506.2 Exhaust openings.*
> Air exhaust openings shall terminate not less than 3 feet (914 mm) from property lines; 3 feet (914 mm) from operable and nonoperable openings into the building and 10 feet (3048 mm) from mechanical air intakes except where the opening is located 3 feet (914 mm) above the air intake. Openings shall comply with Sections R303.5.2 and R303.6.


looks like i don't have much of an out here. i can relocate the bathroom vent termination if need be but i would rather not. i'm going to let it lay and if the inspector says anything, try to argue it is an existing installation and i am not venting combustion gases.

but 1506.2 gets me thinking about 1502.3. does 1506.2 'trump' 1502.3 for a dryer vent termination or is 1502.3 an 'exception' that allows dryer vents within 3' of openings if called out by manufacturer? if so, why would a dryer vent get an exception but a bathroom vent wouldn't?

thanks in advance for any insights.


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## carmon (May 8, 2010)

you answered your own question.


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## itsnotrequired (Apr 30, 2010)

carmon said:


> you answered your own question.


for the dryer vent, bathroom vent or both? i'm not following you...


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## carmon (May 8, 2010)

sorry.... i read that the codes you have say three feet for all.... building codes and venting codes differ everywhere... you have to follow the drier instructions and other local building codes...


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## carmon (May 8, 2010)

I agree the drier instructions is what I would follow...


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## itsnotrequired (Apr 30, 2010)

carmon said:


> sorry.... i read that the codes you have say three feet for all.... building codes and venting codes differ everywhere... you have to follow the drier instructions and other local building codes...


yeah, that's where i am a little confused. one sections says three feet for everything, another section says follow manufacturer instructions unless there aren't any and then use three feet. i just wonder if this wimpy 'locate vent termination 12" off the ground' from the manufacturer qualifies as instructions that are good enough to get around the 3' requirement.

i can move the bathroom vent without too much trouble but man, i really don't want to throw a bunch of extra elbows in that dryer run if i don't have to.


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## carmon (May 8, 2010)

I can not speak for your inspectors... in my area they would say nothing .. the only thing coming out of the vent is moisture and lint.... it may fog your window.... that is if it gets cold where you are...lol


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## itsnotrequired (Apr 30, 2010)

carmon said:


> I can not speak for your inspectors... in my area they would say nothing .. the only thing coming out of the vent is moisture and lint.... it may fog your window.... that is if it gets cold where you are...lol


central wisconsin here so we certainly get our share of cold. ironically, the power-vented gas water heater and condensing gas furnace presently vent only about 18" below the living room window. in the winter time, we get some 'clouding' if the winds are just right but that's about it.

if this was a totally new installation, i wouldn't be locating the vents above this window but as part of a basement finishing project, i didn't want to have some wimpy 1x2 foot window providing natural light and i wasn't going to let a vent location stop me from putting in what i want. if i have to end up moving the vents then so be it.

maybe i won't take the inspector outside when he comes to look at the basement.


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## ben's plumbing (Oct 6, 2011)

itsnotrequired said:


> central wisconsin here so we certainly get our share of cold. ironically, the power-vented gas water heater and condensing gas furnace presently vent only about 18" below the living room window. in the winter time, we get some 'clouding' if the winds are just right but that's about it.
> 
> if this was a totally new installation, i wouldn't be locating the vents above this window but as part of a basement finishing project, i didn't want to have some wimpy 1x2 foot window providing natural light and i wasn't going to let a vent location stop me from putting in what i want. if i have to end up moving the vents then so be it.
> 
> maybe i won't take the inspector outside when he comes to look at the basement.


 did you consider asking the inspector before you install your window..:yes: my save alot of trouble and work


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## itsnotrequired (Apr 30, 2010)

ben's plumbing said:


> did you consider asking the inspector before you install your window..:yes: my save alot of trouble and work


i'd rather re-work some vents rather than have some small, crappy window to look out of for the next however-many-years.

honestly, i never thought of the code implications when i was laying it out. i knew there would be some possible fogging in the winter but that was all i was really concerned with.

eh, we'll see what the inspector says but any insight on this 'manufacturer's recommendations' in the irc with respect to the vent termination location? is something as simple as 'keep it 12" off the ground' a substitute for the 3' clearance?


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## Doc Holliday (Mar 12, 2011)

12" above ground, 3' from an opening into the structure. 

You're going to regret not doing this right the first time around, they always do. Your home is going to look ugly as sin from the outside with those vents on the frame of the window and you'll never be able to open that window without some headache from the exhaust. 

These codes are not just for the heck of it.


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## Doc Holliday (Mar 12, 2011)

So yes, itisirequired.


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## itsnotrequired (Apr 30, 2010)

Doc Holliday said:


> *12" above ground, 3' from an opening into the structure. *
> 
> You're going to regret not doing this right the first time around, they always do. Your home is going to ugly from the outside with those vents on the frame of the window and you'll never be able to open that window without some headache from the exhaust.
> 
> These codes are not just for the heck of it.


if i am reading the irc correctly, it says follow manufacture direction and 3' opening clearance is only necessary if the manufacturer gives no direction. or am i not interpreting the code correctly?

this window won't open very often and the vents are only an issue when they are actually in use. the vents are there from when the house was built. and like i said, the water heater and dryer vents are only about 18" below a different window and the window, siding, soffits, etc. look fine.

if the inspector says i need to move them then i will but i'm not going to bother right now. still curious about this irc '3' vs. manufacturer direction' issue...


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## Doc Holliday (Mar 12, 2011)

It appears that 3' is the city code for you, if that article is from the mechanical code section. 

You're making this way too difficult on yourself. 12" above grade and 3" from any openings. Not sure about your other vents and why they are 18" instead of 36" away from any opening but again, if these articles are up to date and from the mechanical code section for your city than 3' would be what I would abide by. 

I don't know what else to say, that's how I interpret the situation.


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## itsnotrequired (Apr 30, 2010)

Doc Holliday said:


> It appears that 3' is the city code for you, if that article is from the mechanical code section.
> 
> You're making this way too difficult on yourself. 12" above grade and 3" from any openings. Not sure about your other vents and why they are 18" instead of 36" away from any opening but again, if these articles are up to date and from the mechanical code section for your city than 3' would be what I would abide by.
> 
> I don't know what else to say, that's how I interpret the situation.


gotcha, thanks for your input. what makes me think the manufacturer recommendations trumps the 3' requirement for the dryer is in the 2006 irc, it also said manufacturer's recommendations but no less than 3'. that was changed in the 2009 version and is still there in the 2012 version. now it says manufacturer's recommendation and the 3' only applies if no direction is given by the manufacturer. is that recommendations on window clearances or any recommendation at all?

edit: and if this was a new house, i would never set it up this way. just wondering what the actual code constraints are for remodels.


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