The smell is driving me nuts......

[charlezz]

I posted this scenario in dirty sock syndrome, but fact is I don't have a clue. We are in a 16 month old house (second winter) and have been experiencing a musty smell from our return air after we take a shower. The system is a Lennox, but I do not think it has a heat pump. The smell is in no other room except the hallyway where the return air is located. I have had a plumber check the ventilation pipes for cracks, etc., leak pressure test on the water lines, duct camera inspection for mold in the ducts, and air condtioner guys out to check system out. All have no answers. When the duct service man came out, he said our attic did not smell normal so I am in the process of having the insualtion checked. Personally I have been in the attic and this does not smell like the musty smell in the return air. My duct person has suggested a duct pressure test, but I feel this does not solve my odor problem. He did say our house seems to acting under negative pressure because some of our doors will close when the unit is running and when it is off there is a small draft coming down from the return duct. HELP!!!

Charlezz

[Edited by charlezz on 01-26-2006 at 01:08 AM]

[contactor]

We were recently called out on a similar problem. every heating and duct cleaning contractor couldnt figure it out.I still cant either, but we torched the heat exchanger and coil with an acetylene torch,to burn off
whatever.
Something like a deorderizer or bug killer was used and circulated is my theory prior to moving in. Lady says smell is gone and even sent fudge with a thank you letter.

[fatmomcarl]

do u have a crwal or basement ? possibly duct not sealed or that spaces smell reachin living space

[smokin68]

Have your A/C's coil cleaned and see if the smell goes away.....it's downsteam of the furnace supply air.You wouldn't be smelling the return air.

[charlezz]

We have an attic, we do not have a basement.

[contactor]

I talked to you today charlezz,'
When you mention the draft coming down when the unit is off,this can indicate to leaking ductwork. Have someone inspect the ducts for leaks in the attic.A pressure check will indicate the amount of leakage, but not where. A/c coil could still have dirty sock,and most air drafting into bathroom during off cycles. I would say that its impossible to smell anything when fan is running.
The activated charcoal filter may solve the symptom,but not the problem.
Have them check the bath fan vent too.:)

We cannot by code,install returns in bathrooms or kitchens.
Thanx for the phone call,but it is better to send a message on this forum regarding this for me.
Good luck and let us know.
Contactor

[Edited by contactor on 01-26-2006 at 10:24 PM]

[cem-bsee]

rather than checking for duct leaks, have the ducts & ALL boxes sealed with mastic.

have the crack between the HVAC ducts & wallboard |floor sealed.

, then check for leaks, then insulated.

[techdaddy]

have a coil cleaned and duct work sanitized by a proffesional contractor

[propmanage]

You have two issues
1. A draft that should not be.
2. A smell that should not be.
Have what ever dampers needed to be installed installed and get that system balanced or repaired. While doing this tell them to locate and inspect all duct work have everything sealed up nice. This will not only save you from the smell but save you money. You should not have air moving through the ducts while the unit is off unless you have some type of a problem. Can you describe the layout for supply and returns with unit location and duct material and location?

[propmanage]

Do you think they may have cut the bathroom exhaust into the return duct? Why would you have a return in a bath room? I would think that would be a good clue.

[dougfamous]

Do you think they may have cut the bathroom exhaust into the return duct? Why would you have a return in a bath room? I would think that would be a good clue

Sadly, I have seen this before in new homes. I have also seen the dryer vents piped into the return. Time to pop off the exhaust fan and find out just where it goes. You may also want to consider a make up air/air to air exchanger to help with the negative.

[charlezz]

Hey Propmanage...thanks for the response. I did not mean a return in the bathroom; I meant we have a register and an exhaust fan in the shower area. When I get in the attic, the ventilation from the exhaust goes to the roof and out. As far as the layout. Our return duct is in the hallway and the duct goes through the attic and out the roof. We have a dual pack unit with everything located on the roof. In the attic, of course the reutrn air duct, along with the plenum and ducts branching off of that and going to the various rooms. The plenium box is also partly in the attic with the rest going to the roof where everything else is located. Hope that makes sense. Where could the smell be coming from? A serviceman came out and apparently cleaned the coil and sprayed Biofresh. Not sure if the Biofresh was sprayed on the coil or in the unit area. Could the smell still come back after that? Thanks

[Edited by charlezz on 01-30-2006 at 02:27 PM]

[propmanage]

Check the unit over you should not have air moving while off, also you may have a mouse or a damp rage or something in the unit. Coils can become homes for smell and germs if not property taken care of. Shut the power off and get close to the supply and return at the unit, see if you smell it at that starting point. Also almost sounds like you have an open outside air intake full open and possibly getting rain in it. Don’t really know with out being there. Just keep looking until you find it, and you will if you take your time. That air moving is an issue to resolve.

[t527ed]

is plumbing vent stack near rooftop unit where smell could be fnding its way back in?

[charlezz]

Thanks guys for the tips. I am scheduling a pressure test as we speak. Originally my duct technician was suggesting the insulation, but I am not sure if this is the source of the problem. I was also speaking with a buidling science manager in Virgina who is with the insulation company and he was talking about using a blower door to see about the pressure of the house. My duct technician said he did not want to go down that road yet, due to the tightness of the house already. My duct tecnician stated his goal is to keep the air in the house seperate from the attic/outside air. My dilema, hope of course, is if the smell goes away is that a good or bad thing. Good because I do not smell it anymore, but bad because it is still existing.

Could the smell still be coming from the coil even though it may have been cleaned once?

[charlezz]

I never solved issue...any help

[chucko615]

You've got to be kidding...................:eek: It's been almost a year.

[smokin68]

Did you follow any of the advice you were given a YEAR AGO?

What did you have done?

[charlezz]

Even worse, problem has been there for three years. The crazy thing is it only occurs during cold nights. In California, it has just been getting cold lately. I did try everything last year with no luck. Someone also came out and used a cleaning solution on the coil. The unit is a Lennox dual pack and I have narrowed the odor to be coming from the bottom of the cooling coil and the return. On one of the nights last year, I got up on the roof and pulled the paneling off and stuck my head between this narrow area (between return and bottom of the cooling coil) and this is where I noticed the odor. The smell is only when the heater has not been running. Once the heater turns on, the odor is gone obviously because of the heat. I have also been able to smell it the odor, by turning the cool/heat off and running the fan on. When I do this, I will step on a ladder and put my nose next to one of the registers in the house and am able to smell it.

The original installer has come out and also did a static pressure test which was within normal range.

In one of the past post, someone did say about a using a deoderizer. I know in the beginning, we did have a plug-in in the hallway which is in the area of the return. Is there some crazy reason why the odor would have went up the return and did something. Just searching for anything. Its killing me not to be able to find it.

Chuck

[ColdairGuy]

This can't be rocket science! 3 years and no fix?

Where are you located in cali? If this were my house and couldn't figure it out for three years I would have pushed it off the roof

[hivacer]

Is the unit level? Does the drain have a trap and a vent after the trap? I would really like to take a look at this.

[J-HITMAN]

You have two issues
1. A draft that should not be.
2. A smell that should not be.
Have what ever dampers needed to be installed installed and get that system balanced or repaired. While doing this tell them to locate and inspect all duct work have everything sealed up nice. This will not only save you from the smell but save you money. You should not have air moving through the ducts while the unit is off unless you have some type of a problem. Can you describe the layout for supply and returns with unit location and duct material and location?

I was called out to repair some duct under a crawle space and also a funny smell! well i got to repairing the duct and i noticed I was laying in a pool of dead possum! the possum got stuck in the duct and died! It smells like dirty sock? yes! clean the coils, fan, and return air duct! Also stop putting the dirty close hamper infront of the return air!!!!!! lol!!!

[charlezz]

Thanks for the response hivacer...I believe the unit is level. There is a trap and vent...would this be to stop the sewer gas smell? I believe someone else asked this question when they came out. I live in Clovis California.

[J-HITMAN]

After you take a shower? i wounder if its a stink pipe on the roof clogged up?
then the smell is coming out of you drains? well, Thats what the traps are for>??? where is the condensate draining? get the stink pipe checked and make sure the roofers didnt drop a coke bottle down the pipe.?

[JBM1000]

9 out 10 times it's sheet rock dust from non caring sanding crew and even if you tried they don't give a ****. You end up getting the stale wet powder caking your everything. Only real remedy is total 100% rip it all out and do it again. :(

[mark beiser]

Replace the indoor coil with a new coated coil.

[charlezz]

Thanks for the replies guys...

Mark, do you mean replace the cooling coil? Sorry, not in the business and not exactly sure of all the terms.

Hitman, the condensate pan has a drain that comes out the unit and is attached to a pipe that goes down the inside of the house. I am thinking this is one of the sewer lines. Not exactly sure if this is what the line is called.

Thanks

[bluestone]

Charlezz, I'm not an HVAC tech, but I am a builder. HVAC guys have mostly been looking at this from their side although they have touched on a possible cause.
You say the condensate pipes go down the inside of the house, If they are cut into the DWV vent and not properly trapped or poorly installed the odor may be from the sewer system (not a good thing).
Also you say it happens after the shower fan has been run, leads me back to the bathroom. If the house becomes depressurized when the HVAC system is on and the fan vent, DWV stack or both are near a soffit, ridge, or gable vent, these exhausts may be entering the HVAC and being blown into the conditioned space. (not my first choice but possible).
More likely the first scenario because if you are running warm water in the DWV system vapors will rise and be brought up by the chimney effect of the DWV stack.
Hope this helps, what is it Sherlock Holmes says? If all obvious choices have been exhausted, the answer is the least obvious no matter how implausible.

[propmanage]

I thought you already checked the drain ?

[marvin]

post # 19 says this is a lennox dual pac. with an rtu why would the
condensate be piped back into the house? if it is
dropped into a vent & the condensate trap is dry it
could very well suck in odor from the vent. try repiping to
the edge of roof

[smokin68]

post # 19 says this is a lennox dual pac. with an rtu why would the
condensate be piped back into the house? if it is
dropped into a vent & the condensate trap is dry it
could very well suck in odor from the vent. try repiping to
the edge of roof


Here is the likely culprit. Good catch. However, piping to side of house could be against code. When the shower is run, the shower trap fills up with waste water, and the odor goes out the vent stack along with the sewer gas. If the condensate is piped to this at the roof level and it's trap is empty, unless it's a positive pressure trap it's going to mix that smell in with the supply air. The way the condensate line is run sounds like your entire problem......