Marti, who knows what evil LURKS in the ducts of man.....THE SHADOW KNOWS. Truly it can be a frightening problem.

Speaking as one who was on a 500 ton vessel (about 250 feet long) which had mold growing in the ductwork, and where everyone became sick, I know there can be problems to your health caused by such ducts. On the boats, they put the insulation INSIDE THE DUCTS and not outside. Disaster waiting to happen. We also had to replace the dryer duct, which was so heavy with goop and WATER, that it was all one person could do to drag it out of the boat.

Other than plain old respiratory distress, it can lead to Legionaire's Disease, which is what they were worried about on the boat. When I left the employ of that company, they had replaced a lot of the ducting, but not all of it.

What material is your ductpiping made of? Galvanized metal? Thin foil-like aluminum? If they roto-root the inside and the insulation is attached outside the ducting, it should not damage it too much. You may have to plan on being out of your house during this process though.

Get the people who do this work to explain exactly what happens and what they do to remediate the problem.

In the meantime, if nothing else, you can set a big pot of vinegar and water on the stove and humidify the house with the acetic acid of the vinegar. Just for good measure, put some cinnamon and cloves into it for an apple pie smell. Vinegar is a great germ killer, and I think you'd benefit from letting this work its way into your ducting. It won't remove the gloppety goop from inside the ducts--you'd be surprised what that looks like, it is unbelievably gross.
(Think about the stuff on the blades of your ceiling fans, to begin getting an idea, multiply it by the number of years the ducts have been in place.)

Do you have a Serv-Pro that cleans up houses after fires and floods? Just an idea there, don't know if they do it or not, but they'd probably give you a lead.

I hired a duct cleaning company.

We bought the house sight unseen, and while relatives looked at it and sent a million high resolution photos, unfortunately they weren't in smellovision. Actually I did wonder why there were candles burning during the showing and soon found out why. When we got to town and had access to the house I knew immediately that I couldn't deal with the stink and would not be able to spend the first night there without something drastic happening. I have lots of animals and know what wet dogs smell like, but this was what smelled like ten years of dirty wet dog. I found the duct cleaning guys in the yellow pages and they fixed me right up.

Here is a photo looking down into a cold air return before they cleaned.
{{!gwi}}

Here's the photo of what they sucked out of my ducts-
{{gwi:1593453}}

It was almost 100% dog hair, with bits of insulation and cookie crumbs and everything else that had fallen down a register in the decades since they had been installed.

I am unable to remember exactly but I think it cost something in the neighborhood of $300 and took them about four hours or so. They blocked off all the registers and sucked the main line with that huge and mighty vacuum unit that you see there- they wheeled it right into the basement and tapped into my main trunk line. Then they sent a motorized twisty snaking brush through all the ducts, sucked again, then ran the brush again with some sort of cover on it, then sucked again. Last they fogged the whole system with a mold killer of some sort and presto change-o my house smelled clean!

I would recommend this to everyone!!

Cearbhaill, that is AWESOME. Money WELL SPENT.

I agree! That is much cheaper than a year's worth of candles. I have an air filter running 24/7 and still the house smells musty when I have been gone from it for a few days. I used to think it was because the house was shut up while we were gone, but the last time, I was gone and dh stayed here and the smell was the same. When we get through with the next leg of construction I am going to do this. Probably pointless to do it before ripping the side of the house off.

Marti, come on back and tell us some more if you've gotten far enough to do the duct cleaning?

Yes, I had the duct cleaning done. They didn't show us how much stuff came out. So far we can't tell any big difference with the musty smell in the house. I haven't been able to clean either, so don't really know if it is helping with the dust. I need to at least clean the bathtub so I can have a white background test area.

cearbhaill- Thanks for sharing so much info! I think I'm going to try this after we finish our last two messy projects (drywall and whatnot). If it can get the stink out of our old house before we try to sell, it will be money well spent!!

Once again the smaller homes forum is super helpful and timely! I have been in the E-room twice and through tons of specialists and tests in the last two weeks...we're beginning to think there may be a dust/mold issue in our house. I have never smelled it musty at all but my mom thinks she has smelled something. I'm going to look into the duct cleaning (house is 60 years old) as soon as our finances recover some from the dr bills. In the meantime though I'm super interested, Moccasin, in your vinegar idea...do you boil it for a long time?

NOT to hijack this thread at all - Has anyone had any experience with the box air purifiers? My parents have one and have offered it but I read that they create a "smog" atmosphere that can be dangerous to athsmatics?

Enigma, sorry to hear you are having issues with asthma.
Vinegar is one of the best cleaners for all sorts of things. When I use it as a deodorizer, I boil it with some water and then cinnamon and cloves to give an apple pie. Actually, I do not recommend hard BOILING. That might make a steam over your windows. What I do recommend is that you simmer this stuff. Please do not let it boil dry, because that would smell bad I'm sure.

I have an air purifier that I bought from Austin online, and is I got the superduper model to remove the enzymes in bird dander, and dog and cat hair as well. The cleaner is on wheels and every day or so, you clean off the holes in the cover, all over the four sides. I have yet to clean the filter itself, and I've had it for about 6 months.

I am not sure how much an air purifier for the whole house costs. Have you looked into a HEPA filter system? I'm not sure what a "box air purifier" is. Could it be what I have?

Our house is air conditioned. We had so much dust from the construction and demolition before that, and sanding of the new plaster coatings, that everything in the house was in bad shape. I washed dishes daily even with just me in the house, filling up the washer with items covered in dust. It seemed to have no end. With a halt on our building projects, and the house closed up, the dust problem is not so bad any more. I still have some issues with bird fluff which rolls like dust bunnies into the corners, but not as bad as before. The Austin air purifier is located in the sun porch where two of my parrots stay. It is a help for sure, but does not totally remove all feather fluff. Maybe it gets the small particles though. With it and the window a/c unit in that room, which pulls a lot of white dander into its washable filter, I see a lot less in the rest of the house.

See if the link below is the product type you mean.

Here is a link that might be useful: Austin Air Purifier

Moccasin, the type they have is "Alpine Air - purifier"...I might give it a try. We also are going to put cheesecloth in our grates to see if that cuts down on the dusties at all.

I did try your vinegar simmer! I liked it so much I told my best friend who is doing it right now. We both love the way it smells and how healthy and fresh it makes the air seem, I actually love the smell of vinegar anyway (used to have to drink apple cider vinegar for health reasons) and it is so good for you and for the house and cleaning...I put a little vanilla extract in there with my cinnamon and some orange peel! I could easily do this every day, thanks for such a great tip...big fan!

We have a Hunter air purifier. Dd's allergist recommended it. She was supposed to shut her down and turn it on at night. It has an ozone option and I turn that part off because I've heard ozone can harm the lungs. She didn't like the noise though. Sometimes I use it in our bedroom but I don't like the door shut at night because it seems to make the musty smell stronger.