Mold in duct work remove the duct work -any disagreements?

Mama Fen

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I'm not going to go into specifics here, but both the EPA and NADCA are getting ready to make some serious changes to the duct-cleaning industry starting as early as September of this year.

If you have enough condensation building up in ducts to allow mold growth, then the mold is just a symptom, not the problem. Possibly the insulation was strapped too tight around the ducts, reducing its R value. Maybe something has shifted and the ducts no longer line up properly. But whatever the cause, the mold will simply return if the source of moisture isn't remedied.
 

Scott W

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Remember that there is mold everywhere. The first question to ask is,"Are the levels above normal fungal ecology levels? If so, why? As Mama Fen indicated, solve the cause not the symptom.

There are several types of duct work. Sheet metal can be cleaned fairly easily. Flex duct might tear if cleaned aggressively. Duct work with insulation on the inside should get replaced with elevated levels of mold. One needs to know the whole picture to answer the question.
 
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keep it clean

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I'm not going to go into specifics here, but both the EPA and NADCA are getting ready to make some serious changes to the duct-cleaning industry starting as early as September of this year.

If you have enough condensation building up in ducts to allow mold growth, then the mold is just a symptom, not the problem. Possibly the insulation was strapped too tight around the ducts, reducing its R value. Maybe something has shifted and the ducts no longer line up properly. But whatever the cause, the mold will simply return if the source of moisture isn't remedied.

Its amazing how much water can accumulate on an air duct that was poorly insulated. I saw one that crossed through a garage. The insulation didnt go over the duct. I was getting ready to install hallway over this area. so i knelt down to hack up the carpet and it was soaked. We thought homeowner dumped a bucket there on accident or something. We see this also when homeowners close registers in a room. The closed registers will sweat and run down the walls appearing to look like a water leak.
 
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Mama Fen

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What changes Mama?

1997 quote from EPA white paper on air duct cleaning:

"Chemical biocides are regulated by EPA under Federal pesticide law. A product must be registered by EPA for a specific use before it can be legally used for that purpose. The specific use(s) must appear on the pesticide (e.g., biocide) label, along with other important information. It is a violation of federal law to use a pesticide product in any manner inconsistent with the label directions.

A small number of products are currently registered by EPA specifically for use on the inside of bare sheet metal air ducts. A number of products are also registered for use as sanitizers on hard surfaces, which could include the interior of bare sheet metal ducts. While many such products may be used legally inside of unlined ducts if all label directions are followed, some of the directions on the label may be inappropriate for use in ducts. For example, if the directions indicate "rinse with water", the added moisture could stimulate mold growth.

All of the products discussed above are registered solely for the purpose of sanitizing the smooth surfaces of unlined (bare) sheet metal ducts. No products are currently registered as biocides for use on fiber glass duct board or fiber glass lined ducts, so it is important to determine if sections of your system contain these materials before permitting the application of any biocide."


Most recent white paper on same topic, with NADCA input:

https://nadca.com/sites/default/files/docs/2016/chemical_products_position_paper_webfinal.pdf


I have no further concrete information on what, precisely, will wind up being registered for use in ducts, but I can tell you that several companies have already taken any language related to HVAC systems off of their labels - most notably, wording regarding the use of antimicrobials or deodorizers on bare sheet metal or plenums in HVAC/R systems. More will be following soon.
 
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pacleaner

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A couple of points if I may

Some things that look like mold are other things and not mold at all.

Only with testing by a qualified lab will you know if it"s mold and the level and type.

Envirocon does not kill mold, it arrests it if used properly.

Envirocon or any other chemical must make direct and prolonged wet contact with the contaminated surface to be effective.

Selling a customer on spraying chemicals that you do not understand and can not possibly completely coat the inside of hundreds of square feet of surface is a scam and stealing money.

Before you offered to spray, did you have testing done? If you spray will you have a re test done? If there is no benefit will you re pay the customer?

We just blow dust out, stick to that. Leave the other things to highly trained and qualified mold remediation labs.