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  1. #1
    Join Date
    Jun 2017
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    Duct board causing unpleasant smell?

    Hi,
    I just had a heat pump installed last week, new ducts in the attic. From day 1 there has been a musty odor coming from the registers in cooling and fan modes. It gets quite strong in some rooms. The installer sent a technician to check; he said the duct work looked very good and that a leak is unlikely. He said it smelled exactly like duct board and that the smell may last for the rest of the season as it off-gases. Is this common and just something I need to live with until it goes away? More importantly, should I be concerned at all about impact on health?

    Thanks!

  2. #2
    Join Date
    Dec 2015
    Location
    Austin
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    I am not an HVAC professional, but I do know a bit about Indoor Air Quality issues, due to personal experience with a condo I bought.

    1. I would talk to the manufacturer of the ducting and see if they verify off gassing issues.

    2. If you really want to know if the situation is dangerous, you can accurate test your IAQ with a breakdown of pollutants.
    Here are two credentialed labs that will provide air testing kits (calibrated air pumps, with sorbent material). You run the test, return and in 5 business
    you know what is in your air and the concentrations. Cost run from $150 to more. I would only check the most effected room.
    https://homeaircheck.com/products/.
    http://www.fike.com/resources/certifications-approvals/

    3. Particulates, pollutants from .3 microns and larger are easy to remove with hepa filter type devices. Don't spend a lot of money. A good cheap one is as capable as the much more expensive ones.
    See:
    http://thesweethome.com/reviews/best-air-purifier/

    4. VOCs are not removed by hepa filtration. Activated carbon can work but be careful. Most units have much tool little carbon to be effective.
    There are a number of PCO, PECO, and UV Hydroxyl devices that turn VOC to CO2 and H20, but effectiveness is still, for me, not fully determined in a real sized residence with a mixture of VOCs. There are also number of *Plasma* devices available, but the same reservation apply.

    5. You can also try a *bake out*. A small rise in temperature casues a large increase in VOC evaporation. Increase the temp in your residence (~85) for a day or so (and yes I know that might be impractical). You can leave a couple of fans and window or door cracked for ventalation. Some leave residenence closed and then open Windows wide after the bake out. Make sure your HVAC pro approves. Of course make sure your fan stays on continuously during the process
    See:
    Google - "bake out to reduce vocs"
    Lot of references.

    Good Luck
    Randy

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  4. #3
    Join Date
    Jul 2017
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    He said it smelled exactly like duct board and that the smell may last for the rest of the season as it off-gases.
    Yea-ah, no. Ductboard doesn't smell musty and it sure doesn't smell for the whole season. It's fiberglass; irritating when you cut it, but not the source of effervescence you are describing. The mastic used to bond the duct work could be the culprit, but it's just as likely you have a moisture problem somewhere that the new installation did not address.

  5. #4
    Join Date
    Jun 2017
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    Thread Starter
    Thanks for all the info Randy!
    Quote Originally Posted by randyf View Post
    I am not an HVAC professional, but I do know a bit about Indoor Air Quality issues, due to personal experience with a condo I bought.

    1. I would talk to the manufacturer of the ducting and see if they verify off gassing issues.

    2. If you really want to know if the situation is dangerous, you can accurate test your IAQ with a breakdown of pollutants.
    Here are two credentialed labs that will provide air testing kits (calibrated air pumps, with sorbent material). You run the test, return and in 5 business
    you know what is in your air and the concentrations. Cost run from $150 to more.
    Good idea, I will see if I can find out who the manufacturer is. I'll probably try the VOC and formaldehyde kit from the first link. Might also grab the Dylos DC1100 mentioned in another thread for fun.

    Quote Originally Posted by randyf View Post
    5. You can also try a *bake out*. A small rise in temperature casues a large increase in VOC evaporation. Increase the temp in your residence (~85) for a day or so (and yes I know that might be impractical). You can leave a couple of fans and window or door cracked for ventalation. Some leave residenence closed and then open Windows wide after the bake out. Make sure your HVAC pro approves. Of course make sure your fan stays on continuously during the process
    See:
    Google - "bake out to reduce vocs"
    Lot of references.
    Now this is interesting. Looks promising from the papers I've looked at so far... will definitely double check with the hvac pro

    Quote Originally Posted by rmdingler View Post
    Yea-ah, no. Ductboard doesn't smell musty and it sure doesn't smell for the whole season. It's fiberglass; irritating when you cut it, but not the source of effervescence you are describing. The mastic used to bond the duct work could be the culprit, but it's just as likely you have a moisture problem somewhere that the new installation did not address.
    What kinds of moisture problems usually cause this?

  6. #5
    Join Date
    Jun 2012
    Location
    Northern NV
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    971
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    Brand new ductboard has a certain "funk" to it that soon dissipates. Installed tons of it. Never had an issue.

    Now your evaporator coil might be another whole issue as it can get really musty from mold and mildew. A really good filter that keeps "mold food" off the coil will go a long way towards sweet air. (did your system get run during new construction....without a filter perhaps? Sheetrock mud stinks to high heaven in moist ductwork)

  7. #6
    Join Date
    Dec 2015
    Location
    Austin
    Posts
    41
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    Quote Originally Posted by djangomango View Post
    Thanks for all the info Randy!
    Glad you found the info helpful. If you do test with *Home Air Check* i'd be interested in your results.
    We can compare I've done two test with them over the last 18 months.

    Found this and it really adds a lot of detail to your inquiry.
    http://www.greenhomeguide.com/askapr...ac-duct-system

    Also I think both the HVAC professionals that responded make a lot of sense.

    Regards
    Randy

  8. #7
    Join Date
    Mar 2013
    Location
    Billington Heights, NY
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    10,213
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    Quote Originally Posted by Juan Madera View Post
    Sheetrock mud stinks to high heaven in moist ductwork)
    It smells like rotten potatoes
    Experience - knowing when to get the hell out of the way and plug your ears. "Don't be a sissy. Turn it on!"
    Poodle Head Mikey - "the world is well populated with the unknowing and the uncaring and the stupid."

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