Results 1 to 13 of 13
  1. #1
    Join Date
    Jul 2014
    Location
    South Florida
    Posts
    3

    Confused White flakes coming from vents "mold"?

    I have had some breathing difficulties and my eyes are burning when I wake up in the morning. I contacted my doctor who prescribed antibiotics’ and zertex, but nothing had any positive effect. I started to think it was an allergic reaction to something and started to look around the house. I discovered a large hole had opened up under my new air handler which allowed hot humid air from under the house to enter. I checked the AC coil and discovered it was covered in dirt and what looked like mold. I cleaned the coils and things got better for a day then I had to cleaned it a second time . Still wasn't feeling well so I stripped down the air handler and cleaned everything with bleach. I also put an inspection hatch in the plenum and cleaned that also with bleach. Finely I fogged the entire system (twice) including the duct work with a biocide disinfectant. My breathing was better for about 2 days after each fogging, then pieces of white stuff started coming out of the AC vents. Looks like snowflakes. When you try to collect them they crush into a powder, much like ash would do. Does anyone have any idea what this may be.
    My guess is imploded mold spores killed by the Broad Spectrum Disinfectant. I’ve heard that what happened to mold when it hit with a biocide but Nowhere did I see any reference to expect white flakes.
    Can anyone confirm this or have a different idea?

  2. #2
    Join Date
    Feb 2008
    Location
    Altmar, New York, United States
    Posts
    4,997
    what type of filter? at this point a good media filter would help. how is the humidity in the house? you may want to get a pro in to inspect the unit. bleach can create new problems while fixing others. some metals don't like bleach either. is the coil draining properly? where is the air handler located and is it metal duct?

  3. #3
    Join Date
    Jul 2014
    Location
    South Florida
    Posts
    3

    Thanks for your reply

    Quote Originally Posted by snupytcb View Post
    what type of filter? at this point a good media filter would help. how is the humidity in the house? you may want to get a pro in to inspect the unit. bleach can create new problems while fixing others. some metals don't like bleach either. is the coil draining properly? where is the air handler located and is it metal duct?
    Filter is high quality and just installed a few weeks ago. Humidity is now good, now that I fixed that hole. Coil is clean and draining great now that I hit it with the coil cleaner. Air handler is mounted vertically in a first floor closet. I didn't clean the coil with the bleach only the coil cleaner. I've already had the entire unit apart, the white stuff is definitely not coming from the unit or the phleum. Only place I haven't been able to check in inside are vents, most are metal, a few are of the small ones are flexible . the white stuff is mostly coming from the larger metal ducts. Thanks again, Regards John

  4. #4
    Join Date
    Jan 2001
    Posts
    8,121
    Its not that "white rust" is it....

    I know some guys who bought some metal at a deep discount once because of that white stuff all over it in patches...... one of them working with it got sick....... and it was a reaction to that white stuff.... whatever it is.
    YOU SHALL REAP WHAT YOU HAVE _______ SOWN

  5. #5
    Join Date
    Jul 2014
    Location
    South Florida
    Posts
    3

    I've have heard the term before "white rust" what it is?

    Quote Originally Posted by corny View Post
    Its not that "white rust" is it....

    I know some guys who bought some metal at a deep discount once because of that white stuff all over it in patches...... one of them working with it got sick....... and it was a reaction to that white stuff.... whatever it is.
    I've have heard the term before "white rust" what it is?

  6. #6
    Join Date
    May 2009
    Location
    Cummins, GA
    Posts
    1,552
    Just curious, what kind of HVAC equipment do you have? And is it fairly new?

    There is one specific manufacturers who has had a problem with their evaporators coils turning white and flaking off in large amounts.

  7. #7
    I've seen the white flakes before in a industrial office but never could figure out where it was coming from ....another company sub contracted us to encapsulate the duct and as far I know they have no more problems


    Sent from my iPhone using Tapatalk

  8. #8
    Join Date
    Jun 2003
    Location
    Madison, WI/Cape Coral, FL
    Posts
    6,599
    You have become sensitive to something in your home. Most people are not sensitive to a small amount of mold. But once your immune system starts reacting, you can be very uncomfortable.
    I do not know about the white stuff. Wet crawl spaces/basements can make you sick. You need to keep them dry. Plastic on earth and <60%RH is a must. This means closing the vents. Also, you need a fresh air in 4-5 hours when the home is occupied to purge indoor pollutants and renew oxygen. Once you load the ducts with mold spore and you get sensitive, keep the home and ducts <55%RH when not cooling to avoid any biological materials from growing. This can get serious.
    Afresh filtered air change is typically about 80 cfm of fresh filtered air when the home is occupied. The simplest way is to get a small whole house ventilating dehumidifier that will bring in the fresh filtered air, blend it with the house air and keep everything dry. Your air a/c needs to be dry for 4-6 hours every day to prevent mold from growing in the humid ducts around the cooling coil. Also pitch the drain pan to drain perfectly so it also dries.
    The are several brands of small whole house ventilating dehumidifiers on the market. Ultra-Aire/Santa Fes are the granddaddy of them. They can be located in utility room and duct into the a/c ducts with a fresh air supply from outside. Most important is fresh filtered air and maintain 50%RH throughout your space, including the crawlspace and ducts when not cooling.
    Keep us posted.
    Regards TB
    Bear Rules: Keep our home <50% RH summer, controls mites/mold and very comfortable.
    Provide 60-100 cfm of fresh air when occupied to purge indoor pollutants and keep window dry during cold weather. T-stat setup/setback +8 hrs. saves energy
    Use +Merv 10 air filter. -Don't forget the "Golden Rule"

  9. #9
    Join Date
    Jul 2013
    Location
    Richmond, VA
    Posts
    783
    You might benefit from a good duct cleaning if all that mold residue was swept into the duct work after cleaning the coil. Inspect the air handler periodically to determine if mold is returning and if so you might want to look into installing a UV light.
    I'm terrible.

  10. #10
    Join Date
    Jan 2001
    Posts
    8,121
    Quote Originally Posted by windboater View Post
    I've have heard the term before "white rust" what it is?
    I dont know the composition of white rust..... but its that white powder that grows on metal that has been wet.....
    YOU SHALL REAP WHAT YOU HAVE _______ SOWN

  11. #11
    Your issue is with the coil. Trane has had problems with the aluminum coil in areas with sulfur. I am in Naples, Fl. and just had the problem addressed with coils that are now dipped in epoxy (black). Call Trane or an authorized dealer. If your unit it not a Trane, determine what the make up of the coils are.

  12. #12
    What is the brand of your system and when was it installed? Did your health problems occur within 6 months of the new system installation date?

  13. #13
    Join Date
    May 2014
    Location
    Bay Area California
    Posts
    1,503
    I've never heard of white rust before, but if the ducts are steel and insulated on the outside, then it might be zinc oxide. I've never heard of anyone being allergic to zinc oxide, but I suppose anything is possible. We've all seen it before, an old piece of galvanized metal sitting outside where moisture has hit it, and that white stuff forms.

    Except for the plenums right at the unit, most new duct work in homes is alumiflex, not steel. So you wouldn't have that problem.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event