Central Heat/Air Vents Smell?

[bpp]

In early January we started smelling a funky odor.. sorta like a musty funky smell coming out of our vents (not egg smell). It got to be so overwhelming, we shut all the vents and used electric portable heaters for heat for the remainder of the winter. (that wasnt fun in iowa .. we normally have propane heat) We couldnt get under our double wide (94 Century Mobile Home on piers) because we had so much ice and snow that we couldnt dig under.

Now that the ground is thawed and its time for air conditioning, we still have this smell. We crawled under and checked all along the tubing to the vents and nothing was down or damaged. This tubing lays on the ground (its all dirt floor under there). There is no standing water under the house and the dirt is not really even muddy, just damp, which I would expect. All the ducts are still in tact under that plastic seal so from underneath all looks fine. (made a small finger sized slit near water areas and no water is there, the insulation was dry) We havent seen any mold or water in the ducts thru the vents in the house, altho they do look kinda dirty when you look from inside the house down into the vents. The inside of the ducts themselves have an insulation all around them on the inside.. was wondering if those could grow mold or something to make it smell this way? I dont see any evidence of mice or bugs of any kind either. Is there any way to clean the ducts ourselves from inside the house or does this mean we would have to rip down everything from underneath? Any ideas on why its smelling funky like this?

Also under the double wide, our furnace has a tubing that starts at the (east) back of the house and tunnels up to near the front (west) that leads up to a T duct.. that T then has ducts that go west to the front two vents of our kitchen and master bath and from there they go back east along each side to hit all the other vents in the house. The former owner was a relative of ours and she always ran either the air or the heat year round because she had breathing problems and needed a constant temp/humidity level to be comfortable and had never had this problem of the smell. We moved in here in Dec 06 and didnt have the smell until Jan 08.

Thank you for reading my post - Any advice or suggestions or clues would be greatly appreciated. I will check back to answer any other questions that you may have.

[Yanita]

Hi,

Welcome to the site!

I am going to move your post to the HVAC (Heating Venting and AC) forums. Our tech over there is excellent and would be best suited to answer your questions.

Please follow over there...

Yanita

[steve]

Sounds to me like water got down thru the vents (water overflo above) You will probably need to have a company come out to clean and sanitize your ductwork. Its usually around $150

[bpp]

Hmnn.. how would water get into the vents? We havent had any type of water leak or plumbing problem. We did have a flood in town in Aug 07 but the water was only about knee deep and the bottom of our trailer is higher than that.

Thank you for the quick reply and the info about the cleaning also

[garrett_reukauf]

Just a thought, but maybe the drain tube for the condensation that comes off the coils inside you MH has become, or at one time was clogged. That being said the condensation from the coils would have no where to go and back up in to your system. Most drain tubes like this run to the outside. Sounds like the coils maybe need to be santized and deodorized, got a lil moldy mildewy gunk on them. No big deal.... Just like Steve said, have a HVAC duct cleaner come and take care of it. Not only could they possibly get the smell out but your duct work would be nice and clean, which means more efficiency. I wouldn't suggest doing this yourself, could be really messy to an untrained person, plus you run the risk of damaging something that could cost $100's to fix, leave it to the pros.
Good luck!

[bpp]

Thank you all I will have someone come out soon to do just that I appreciate all your responses and help. This is my first time in a mobile home so I have lots to learn!

[Yanita]

Hi,

I am not a tech, but there a couple things that need to be address.

No home is suppose to have the ducts laying on the ground. That needs to be address.

Also in your original post you said you had a flood, and that it did not effect the home as the home was more than a foot high...that being said was your duct on the ground at that time?

As I said, I am not a tech but you need to be real careful about who cleans these flexible ducts.

Also since they are on the ground it is possible that a small rodent has made a small entry in the duct and died in there.

One more thing, you said it's dirt and damp under your home. That said you should consider putting down a moisture barrier. This is a minimum 6 mil plastic that you lay on the ground underneath the home. At least 80% of the ground needs to be covered. This plastic keeps evaporating moisture from penetrating he bottom of your home.

Hopefully Robert will come along and offer some of his advice/opinions.

Yanita

[Robert]

Hi,

Sorry, been away from pc this w/e. You cannot clean ducts lined on the inside.


Secondly, finding someone truly able and experienced enough to clean a thin and flimsy mobile home duct of any kind is doubtful.


The cross-over duct on the ground needs to be off the ground.


Best to install 90*elbows and/or Tees where needed and stretch flex duct tight between them.


Those lined ducts can/will form mold/mildew if they get wet at all and your a/c drip pan and/or drain line could have overflowed.


Could also be from the a-coil in what is called "dirty sock syndrome" which is due to moldy/mildewed coil.



Due to risks of above, best to call an HVAC Tech to inspect entire system.



Thanks for inquiring,
Robert

[bpp]

Hmnn well my ducts dont lay on the ground. They arent even visible. There is only one thing that looks like a big tube that does lay on the ground and my neighbors have the exact thing also. Maybe I will take pics because I really cannot describe it.

OK so if I cant clean the vents or have someone clean them, then whats left to do? Do I need all new ducting? This would also mean all new insulation and that plastic that covers the underbelly, no?

In any case, sounds like its too expensive for me. I live on a fixed income.

[Robert]

Hi,

The duct on ground is the cross-over duct and it should not be on ground. See my previous post on how it should be.


The main trunkline would only need replacing if damaged.


Once that lining gets wet, trying to clean it or salvage it is almost impossible without destroying the ducting itself in the process.


The belly can be opened and resealed if the ducting needs replaced.


It is a tedious and time consuming job and costly.


Let a Tech inspect system, may not be the ductwork.




Thanks,
Robert

[bpp]

OK did a little inventive "looking".. opened up all the vents in the house (from in each room) and stuck a good bright flashlight and a digital camera and a compact mirror into each duct. Took pics and could see the end of the duct or down to at least where the next vent was in the room or next room.. and to my surprise there was NO dirt, no mold, nothing torn or damaged or discolored, no rodent droppings - nothing but pure yellow lining each duct. It was clean.. I couldnt believe it. The only parts which looked dirty are were the vents actually reach the room so I guess from walking etc the dirt would fall thru. I stuck my head down in there and could barely smell that smell that I was previously smelling. Phantom smells? lol I dont know!

So took my vacuum hose and vacuumed around where I could see dust and sprayed lysol inside. I stuck my arm down in there as far as I could reach and nothing felt damp or wet. When I have more time this week I will go back under and take some pictures to show yall what its like down there from the outside to give you a better idea of what I'm dealing with.

Thank you all for your inputs.

[Robert]

Hi,

That's great and that is method we advise for inspecting ductwork. The camera adds a degree of fine tuning for visual purposes.

May be the a-coil or any number of things, smells/odors can travel and be mind boggling at times.



You're very welcome, happy to help where I can.


Take care and best wishes,
Robert