What to do with Mold-Contaminated Ducts

02.10.2010

New York, New York – Traditionally there has been a movement amongst those responsible for HVAC care in a facility to simply replace the affected areas where mold had grown. This is due to the serious health effects that the growth of these microbes can have on people. Unfortunately, this is quite often not a cheap undertaking and it leaves either the insurer or the owner of the property footing the bill when another solution is possible.

Mold can grow on virtually any surface that is part of an HVAC system. The most common places to discover mold growth are coils and internally insulated products. However, it is also possible for mold to grow on a variety of metal surfaces including galvanized ducts, aluminum smoke dampers, or stainless steel.

Once mold is discovered, it should be dealt with in a timely manner. Putting off the maintenance needed to deal with the mold will likely result in even greater damage and a more costly solution. Given the right conditions (for the mold), for example, a small cluster of mold on a cooling coil could realistically cover the same coil completely within a few months. This could result in less airflow, an increase in energy consumption, as well as harm to the occupants.

There are steps one can take to remediate mold instead of settling for costly replacements. Here are some solutions given certain scenarios and mold locations:

1. Heating and Cooling Coils: There are coil cleaning products to remove the spores which have a reasonably high success rate in mold removal. However, the deeper that the coil goes, the harder it will be to remove all of the mold. If during the cleaning the coil will stay in place, attention should also be given to the engineering controls so the spores that will become airborne during the process can be handled as well.
2. Non-porous surfaces: This includes galvanized ducting, fire dampers, smoke dampers, fans, and shrouds . Mold removal should be relatively simple and successful from these elements of your HVAC system. To clean them, first remove the visible mold growth and then disinfect the surface with an EPA approved solution. These elements should be reasonably accessible inside the system.
3. Internal Insulation: This is possibly one of the hardest areas from which to remove mold. Successfully remediating the mold from these areas may not be possible in some cases and replacement may be your only option. It is recommended that porous areas thathave been infected be removed and replaced. One of the greatest difficulties with regards to fixing mold in these cases is access. More than likely to remove the internal insulation in a duct, the duct has to be disassembled, which is a chore in and of itself. To further complicate matters, replacing the insulation is not an easy task.
4. Flexible Ductwork: The remediation of this type of ductwork is usually not practical because the product is cheap enough to be replaced. Also because of the makeup and placement of the materials themselves, remediation could also be hard to accomplish.

It should be noted that undertaking such a project is not without its dangers. Use of HEPA Vacuums as well as HEPA Negative Air machines is recommended to control any spreading of the mold. Failure to control the environment could result in more costly repairs and in extreme cases, total infestation.

Once the mold has been successfully remediated, one must take steps to prevent the growth of mold again. Some simple things that can be done to ensure this such as tracking the relative humidity in the system and making sure no excess water is present. Also, getting regular inspections should help in keeping the system secure.