Thread: Exhaust venting into plumbing stack?

Today I saw a very "creative" way to vent bathroom fans. The fan ducts were attached to a T fitting in the 4 inch ABS main sewer vent stack in the attic, just below the roof. I have never seen this before, and at first thought, considered it "wrong". After sleeping on it, I am having a hard time coming up with any legitimate reason it can't work and can't think of any problem it could cause.? Any thoughts?..........

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Originally Posted by brent lerwill

Today I saw a very "creative" way to vent bathroom fans. The fan ducts were attached to a T fitting in the 4 inch ABS main sewer vent stack in the attic, just below the roof. I have never seen this before, and at first thought, considered it "wrong". After sleeping on it, I am having a hard time coming up with any legitimate reason it can't work and can't think of any problem it could cause.? Any thoughts?..........

I can imagine conditions, especially when the fans aren't running, when sewer gases could enter the house by way of the fan vents.

Besides the not allowed aspects and improper plumbing connection to stack (tee in and of itself at that elevation to something below even if circuit vent for plumbing system) you are seeking justifications for the non-compliant "idea" of the DIY debacle?

In addition to what has already been mentioned: Okay, pathways for biologic films, organisms cross contamination, offal, soil, waste, etc. Foul air, gasses, etc.

The ventillation fan nor its components are not a part of the DWV plumbing system - not listed or approved for connection to it, it is not a listed DWV material.

ABS pressurized No good. ABS is cemented not solvent welded. ABS when subjected to burning/flame releases cyanide.

Electricity and water don't mix.

The stack goes to the unconditioned area and outdoors. Wind, downdrafts, atmospheric pressure changes, temperature differentials.

Gravity - Not just "sh*t flows down-hill". Air, gas, are FLUID.

Pathways for entrance (stacks are generally open) of creatures, water, etc.

Pressurization of the vent during fan operation, thereby losing the protection of the traps.

No water trap between this exahust termination (tee) and its origin.

And a biggie: ignition of methane gas which at low concentrations (significantly lower than what can cause asphixia) is explosive.

It is a health hazard, danger, safety hazard, fire hazard, and subjects the structure, electrical system, ventillation system for the bathroom, to damage and deterioration. Use of materials and interconnection to systems against manufacturers instructions, their listing and approval standards, etc. etc. etc.

Its just plain, as one of my grandchildren might say, "stooopid".

offal,

Mr. Watson: Impressive!

Not really, Mr. Franson. Just an indication of pre baby-boomer elementary education.

Thanks for your quick, accurate and smart comments. Now I'm embarrassed that I asked and see the wisdom of what has been said. Thanks for saving my A##!!

Originally Posted by brent lerwill

Thanks for your quick, accurate and smart comments. Now I'm embarrassed that I asked and see the wisdom of what has been said. Thanks for saving my A##!!

One should never be embarA$$ed for asking a question. The "stooopid" reference was not intended to have been applied to the question or the one asking the question; but a characterization of the inappropriate installation (installer) itself (him/herself). If they are/were one and the same (questioner/installer)....well; whoops !!!

You are welcome. Sorry if fast (hunt-and-peck) typing of multitude of thoughts came off as harsh, not my intention AT ALL, an unfortunate by-product of advanced age, fleeting thoughts, short-term memory "issues" and limited funcationality of fingers banging on keyboard, and fighting "time-out" clock on log-in activity to get post up!

I deferred the duct versus vent, mech. v. plumbing, etc. discussions to avoid generating such thoughts/feelings. Sorry if came across that way, not intended.

Originally Posted by H.G. Watson, Sr.

Not really, Mr. Franson. Just an indication of pre baby-boomer elementary education.

Mr. Watson: Impressive, but just a bit jingoistic and quite vociferous regarding your membership in the Silent Generation (hushhhhhh!).

Some of us Boomers went the extra mile and classically educated ourselves outside of the "education" system set up by your generation. A few of us possess rather large vocabularies. Heck, some of us can even reason, now and then. A little more respect might be in order . . . or not. That door swings both ways.

Sigh....

"Elliot Franson":

"Your slip is showing!"

OT, hijack, and characteristic pattern, and in fact "classic" A(aron) D. Miller most often used three phrases, all on the same post. Apparently I am older than YOU think.

It is obvious you are here (under a new pseudonym) to defend and represent yourself/yourselves.

Stop playing the same games and thowing around the insults Aaron, it is neither helpful nor amusing to anyone other than yourself.

Saw one like this not long ago. Handy man read my report and starting busting out the dryer vent and duct tape....

Old post but.....Saw my first one today. What were they thinking? The sweep tee bends face downward so the exhaust fan pushes air down the stack. Makes a bad idea Even worse.

Originally Posted by Sal Castro

Old post but.....Saw my first one today. What were they thinking? The sweep tee bends face downward so the exhaust fan pushes air down the stack. Makes a bad idea Even worse.

Photos?

Photos didn't show up on my phone, but I see the photo now that I am on my computer - there is nothing remotely even close to be good about that, not even if the fitting was turned upside down.

That's a recirculating fart gas array. It is the new requirement for energy efficiency, or so they say. We shall see if it actually works that way or just blows up when somebody lights a candle.