i work at a school and for the last 13 years there has been reports of a smell that comes into the school through the A/H system the reports are from a-z including rotten eggs rotten cabbege to gas sewer smells. i asked this same question last year with great answers from you guys but nothing seemed to work. we have brought in 2-4 "experts" but none of them can find the source of the smell......we have poured anti-freeze in the trapd that are no longer used...ran water down the roof vent pipes...extended the roof vent up so that any smell does not get sucked back in have cleaned all of the duct work and coils it seems that when we clean the school in the summer there is no smell but about after the first 2 weeks of school the smell is there. 2 years ago it went from sept till about nov. then once the heat was on all the time it did not smell ...but last year the smell was there from sept till june.any ideas or help
Where are you located? Does the air conditioning operate some of the time, all of the time when the odor is noticed? Has a smoke test been done?
Any kids have a parent named Twilli something?
Last edited by Heavyevans; 10-14-2008 at 04:23 PM.
Reason: Couldn't help myself
RTUs or central plant? Could the return be leaking? Any open economisers or fresh air dampers near exhaust fans? Sounds like you've covered sewer venting. I had one that a plumbing trap primer stopped up and the trap was located in a wall. Any time the building got a negative pressure it would smell like sewer gas.
Nemo me impune lacessit.
How much blood do I have to bathe in to get clean?
Don't look down on anyone unless you're helping them up.
Are you smelling it or just the building occupants?
(Dirty Sock Syndrome)
dont feel all alone.......I have it too.
ok i will try to answer all of your questions....mikeylikesit you have it too? do you still have it? what have you done to try and find the smell?....big johnson yes i am smelling it maybe not as much as the dramatic teachers some days it is really strong and others i cant smell it as much as the say they can.......john culpepper we have airhandlers in the basement in this old part of the building where the smell is.and rtus in the new part ,but the smell were there long before the new part was builtwe do have fresh air intakes near roof vent but we extended them way up past the intake.is this different than the exhaust fans the you speak of?.....heavyevans i am in upstate new yorkthere is no a/c in this part of the building no no smoke test yet
the "expert" came in yesterday.his report is that it is not a sewage gas smell but rather a dead animal in the duct work, i find that hard to beleive seeing that the smell has been there for 13 plus years and that in the last 6 years we have had the duct work all cleaned most recently just last summer.so no we are going to bring in another guy with a scope to see if he can find something in the ducts............this is "expert" number 4 4 experts with 4 different opinons.........the saga continues
yea I still have it, but I am making strides in getting rid of it.
I know I will get lit up for this, but here is what is working for me.
50/50 CLOROX and water, with just a dash of soap, run thru a coil cleaning power washer, on the inlet side of the coils. go over the whole coil quickly, then turn on the fan for a few seconds. Yes, in the same direction as the airflow. (I had already thoroughly cleaned the coils from the downstream side, so Im not worried about packing the dirt in....there isnt any dirt.)
I am running a speed drive, so I let it ramp up to about 15 Hertz, and turn it off.
Do this on a Friday night, as the building must, MUST be completely vacant.
Lather, rinse, repeat. I am doing this about 5 times before I see the bleach/water/soap solution actually coming out of the other side of the coil.
REPEAT (on Saturday......again, vacant building required)
Repeat. (on Sunday.)
do it all over again the following weekend.
At this point in time, I believe I have run about 20 gallons of Clorox thru the coils. I typically get "the smell" on Monday morning when the chillers kick off, and get the coil wet with condensate.
So far, so good.........keeping my fingers crossed.
I agree, it doesn't sound like a dead animal to me and if it was, the stench would be unmistakable. All I can think of is that if you've got any sound attinuation insulation inside the ducting, usually just before and after the fan discharge, that is where moisture can collect and cause odors. I've had that problem with over-sized DX units. Considering all the "experts" you've had around, I'm sure they've looked at that.