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Fiberglass Ductboard


Les
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id="left">I have been taking a lot of grief about fiberglass ductboard lately. Just got of phone with a HVAC contractor that threatened my life and good name because the tape was falling off plenumn and warm air return at furnace. Also, I have clients asking about the particulate distribution, etc.. Ownes-Corning has also called me from NY with threats etc.. and sent me a nifty "sales" pack for my education. Does anyone out there have any "world famous" opinions either pro or con regarding use of fiberglass ductboard? My only issue has been suitability for use in some applications and ability to really clean the stuff.
thanks
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Originally posted by hausdok

Hi Les,

You're chasing ghosts. Fiberglass has been proven not to cause health problems and ductboard will be less prone to dumping fiber into the air than fiberglass sound-deadening matts will.

The only issue is sealing. ASHRAE recommended in 1997 that the HVAC industry stop using duct tape for sealing and go to mastic.

ONE TEAM - ONE FIGHT!!!

Mike

When exactly has "...fiberglass been proven not to cause health problems"? Did I miss something?

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My supplier of the UNICO system carried fibreglass ducting when it was introduced in Calgary. We had many concerns and complaints with trades and customers, we've gone back to the traditional galv steel stuff.

The material has a greater chance of harboring undesirable creatures and other issues with restrictive flow etc.

We now recommend smooth pipe, the duct cleaners are happier and we don't have residual construction dust in the system.

My two cents.

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Originally posted by Les

id="left">I have been taking a lot of grief about fiberglass ductboard lately. Just got of phone with a HVAC contractor that threatened my life and good name because the tape was falling off plenumn and warm air return at furnace. Also, I have clients asking about the particulate distribution, etc.. Ownes-Corning has also called me from NY with threats etc.. and sent me a nifty "sales" pack for my education. Does anyone out there have any "world famous" opinions either pro or con regarding use of fiberglass ductboard? My only issue has been suitability for use in some applications and ability to really clean the stuff.

thanks

Is fiberglass ductboard the thick black stuff I sometimes find lining the ducts?

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The ductboard we see here in S. Florida is silver (aluminum) on the outside and yellow on the inside. It's usually used at the mixing boxes and supply/return plenums while flex duct which is plastic wrapped on both the inside and outside is used for the duct runs. The old galvanized metal ductwork is far better, in my opinion, since it creates less static pressure loss and is much easier to clean. My opinion only.

NORM SAGE

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Owens Corning sent me approx 15 art, one video and a partridge in a pear tree. Their site has lots of data as well as NAIMA.ORG. WWW.CUTTER.COM also has stuff. Jim Worden @ jim.worden@owenscorning.com sent me a package of stuff. Of course it is ductboard friendly, but it does seem to have good facts and is a valuable resource and contact. I am informed the lawsuit vs me is continuing and will keep you posted. Likely won't be much action as it is based on tradesperson's feeling getting hurt cost of material/labor and little else. I do mostly legal stuff and we have a law office, but this is a first for us. Thanks for the input!

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The duct board we see here in S. Florida is silver (aluminum) on the outside and yellow on the inside. It's usually used at the mixing boxes and supply/return plenums while flex duct which is plastic wrapped on both the inside and outside is used for the duct runs. The old galvanized metal ductwork is far better, in my opinion, since it creates less static pressure loss and is much easier to clean. My opinion only.

We see the same thing here in AZ. and I agree, Flex & fiber board don't hold a candle to galvanized metal ductwork

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Hi Les,

You're chasing ghosts. Fiberglass has been proven not to cause health problems and ductboard will be less prone to dumping fiber into the air than fiberglass sound-deadening matts will.

The only issue is sealing. ASHRAE recommended in 1997 that the HVAC industry stop using duct tape for sealing and go to mastic.

ONE TEAM - ONE FIGHT!!!

Mike

Howdy folks, first post here.

Now that the niceties are out of the way, to the point of a reply.

I don't know if Les is chasing ghosts as much as he is not pinning the issue more specifically. Mike has a later post that supports his position that fiberglass in and of itself is not a carcinogen. One must remember that safety is not only measured by the carcinogenic nature of a material.

This issue may be more directed towards the "proper installation" of the material than the actual material itself. There is little doubt that improper installation of fiberglass duct board may cause significant environmental problems.

Ball State University has an interesting opinion on its website concerning this material.

http://www.bsu.edu/web/IEN/archives/2000/120700.htm

Bottom-line is if one is concerned with indoor pollutants, mold, or other organic contaminants then one must properly install this dubious material, or better yet avoid it all together.

Not a ghost chase, but a legitimate question that should be discussed more fully before the case is closed.

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We see ductboard seldomly in air return areas under the air handler unit. Fiberglass facing out.

We say that the air return can not be adequately cleaned and dust etc will adhere to the fibers.

I remember Ron telling me that sometimes there is a sticker or label on the air handler unit for units installed in California regarding the prohibition of using fiberglass.

Ellen

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The stuff inside the metal duct is fiberglas insulation, it is supposed to have a sealer applied to the raw edges to prevent fibers from being eroded. I've never seen a res system with the sealer. Ductboard, if incorrectly assembled, has the same failing, it will erode if softer inner part of duct is exposed to airflow.

Personally, I don't like any fiberglas product in the airstream or airhandler.

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  • 4 years later...

Duct board releases fiberglass particles into the airstream, this is obviously a health hazard. Mold is another huge problem. The original product deteriorated rapidly and I have found samples where little more than the paper was left upon removal. In recent years manufactures have improved the product by adding thicker coatings inside and mold resistant chemicals. Cleaning is still a problem. It is now a better product, however fibers are still released, how much greatly depends on the installer's methods.

Because it of its relative simplicity to on site fab, many unqualified installers are out in the market doing sloppy work. Some trained installers still do not fully understand the importance of sealing all fibers. I have even seen installers who do radius fittings by making little slices so it will bend. RADIUS FITTINGS ARE NOT FOR DUCT BOARD!!! Everyone out there doing this-PLEASE STOP. You are releasing fibers for people to breathe and trapping dirt,spores,germs ect.

The cleanest healthiest way to move air is in metal duct with insulation on the outside.

Remember "Cheap ain't Good and Good ain't Cheap.

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  • 1 year later...

The American Lung Association gives the following information on their web site "Facts About Fiberglass".

"Fiberglass insulation packages display cancer warning labels. These labels are required by the U.S. Occupational Safety and Health Administration (OSHA) based on determinations made by the International Agency for Research on Cancer (IARC) and the National Toxicology Program (NTP)." (more at the American Lung Association web site)

That said, this conclusion is controversial. But cancer is not the only bad thing that can happen to the occupant of the house. There are other lung diseases such as asthma and emphysema.

The Illinois Dept. of Public Health states that: (persons with) "worn-out duct work lined with fiberglass in their homes or workplace may have long-term exposure to fiberglass."

Here in Arizona, besides traditional air conditioning, many homes are fitted with swamp coolers. The humidity really causes rapid deterioration of the fiberboard.

Additionally, I know of few home installation settings where there is periodic inspections. The only time someone sees the plenum is at long intervals when the furnace or air-conditioning is replaced. And then its hit or miss if a deterioration is even noticed or discussed with the home owner.

So as far as Fiberglass duct board, if it deteriorates, it is indeed a health hazard, and usually a hidden health hazard.

The lady who lived previously in my home died of emphysema, likely caused by a lethal combination of smoking and chronic exposure to fiberglass. (Compare this to Smoking plus asbestos was associated with much much higher chance of cancer than either smoking only or asbestos exposure only)

When I moved in and discovered this, I had to have the entire plenum and duct work remediation done with sealer and then Fosters sealer. Thus encapsulating the loose fibers and to seal out the moisture from again disrupting the deteriorating fiber board.

In my opinion, contractors who install fiberglass board duct work in homes are creating long term health hazards.

And this is so unnecessary. Interestingly, I have been told that the fiberboard ducts can be constructed "inside out" so the aluminum is lining the duct work and the insulation is on the outside. This insures a metal lined duct, all of the the insulation effect, and a significant contribution of the sound deadening properties. ( I say this as a physician who has had conversations with many "lung patients" HVAC contractors on the patients behalf -- and not as one directly versed in building codes)

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  • 1 year later...

We installed Certee Duct Board in our personal residence in 1977 and used a "wild return" (no duct board, just air return back through a CMU plenum, which contains 3 Heatlator fireplaces) back to the original water-to-air York heat pump unit located in the basement with updraft airflow....We never have had any problems with this system...never any respaitory issues, never any mold issues.....The duct system was sized per heat loads as outlined in ASHREA and ductalator.....Corners of ducts were "cut" using the proper cutting tools for duct board, then stapled and then seal with aluminum tape (not duct tape)....System contains air turning vanes (made of fiberglass) at square turns and transistions pieces to keep the proper air flow velocities....The air supply system was constructed and installed and balanced according to Certee Installation Manual, ASHREA and NABB (balanced)....As far as I can tell the duct board material has not "thinned any" and air has been flowing thru it for 33 years....This is my experience and my opinion using duct board!!!!! Bob...PE since 1970

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  • 2 years later...

One week after moving into my 6 year old house, I discovered the ducts were fiberglass! A few days later I had the entire duct system taken out and replaced with metal. Doesn't anyone remember fiberglass is spun glass? Once inhaled into the lungs it stays there. It is a known carcinogen! The woman next door who has lived with their fiberglass duct work has been diagnosed with thyroid cancer and neither she nor her husband have ever smoked. I believe this will be a future class action lawsuit just as years ago asbestos was found to be harmful to human health. I kept a length of the duct work to show my neighbors and their jaws dropped! They thought, as I did,that the ducts were square metal wrapped with insulation. The rigidness of the fiberglass ducts also contributed to problems with good air flow as the system was installed with 45 degree angles and even one length higher than the other causing the flow to hit against the flat surface before it crept up and over meaning the air exchanger had to work harder to push air through. Love the metal ducts! All rooms now have even cooling. Responsible duct cleaning services will also inform home owners that cleaning their fiberglass ducts can loosen the fiberglass threads. Also, one section of the main duct was not fitted correctly which left interior fiberglass exposed to the main air flow.

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  • 1 year later...

Interesting tidbits, especially the one about the State of Illinois Health Dept.

What else you got?

A little assignment for you, look up what can happen to you from breathing galvanized duct oxidation powder.

Fiberglass is a silicate fiber and can reduce lung function and cause inflammation. It can also cause skin, eye and throat irritation. At higher exposure levels, fiberglass also has been associated with skin rashes and difficulty in breathing. Most important fiberglass duct board today is not the same type of fiberglass. The black duct lining used in every commercial ducted air system, roof curbs, and unit construction has it's own health issues.

Older residential duct board installations should be inspected and do have a life span. You home inspectors should take a look at this. It is simple to test for, and home owners should be informed. Replacing duct work in commercial or residential is not unheard of, all duct has a life span, it all has it's pro's and cons. Installed, maintained and used correctly and all is well. Unit maintenance, as well as duct inspections by HVAC contractors is very important.

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  • 2 weeks later...

a quick check of OC's MSDS info shows:

In October 2001, the International Agency for Research on Cancer (IARC) classified fiber glass wool as Group 3, Not classifiable as to its carcinogenicity to humans. The 2001 decision was based on human studies and animal research that have not shown an association between inhalation exposure to dust from fiber glass wool and the development of respiratory disease.

In May 1997, the American Conference of Governmental Industrial Hygienists (ACGIH) adopted an A3 carcinogen classification for glass wool fibers. The ACGIH A3 classification considers glass wool to be carcinogenic in experimental animals at relatively high doses, by routes of administration, at sites, or by mechanisms that it does not consider relevant to worker exposure. It also reviewed the available epidemiological studies and concluded that they do not confirm an increased risk of cancer in exposed humans. Overall, the ACGIH found that the available medical/scientific evidence suggests that glass wool is not likely to cause cancer in humans except under uncommon or unlikely routes or levels of exposure.

Conclusion: glass wool is not likely to cause cancer in humans except under uncommon or unlikely routes or levels of exposure.

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Wow.... a 10 year old thread revitalized.....

It's one more thing. When I was selling industrial respirators and filtration equipment, we had a list of 187 micro-fibers, toxic dusts, or other nastiness everyone is exposed to on a daily basis.

I'm sure you're right about ducts killing us, but telling folks to change out their ducts is gonna be a hard sell.

Good luck.

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  • 8 months later...

Hi All:

I'm new on this forum and found it while researching the issues with fiberglass ducts in my house, built in 1986. The main air trunk from the HVAC to the flex ducts is made with fiberglass flexboard, it is in the attic. I'm not sure what if any sealant or coating the fiberglass "inside" has on it. Know little of anything about it. The Air Handler is going to be replaced and the contractor was suggesting replacing the fiberglass... what would be the criteria I should use to determine if this is truly warranted? Are there cases that indicate I should leave it alone?

Thanks!

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Good advice, but highly problematic. How does one retrofit metal ductwork into an existing structure?

What about something like Aeroseal for this? Wouldn't that work? Could it work?

Teranz (Tom R) said the trunk is in the attic. It's accessible.

I'm with Erby...let the contractor replace the FG with metal. Git her done and forget it.

Marc

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