Note condensation stains on the plywood under this AC duct. The duct is sweating far to much. Mold grows in the wet insulation under such ducts, and on the exterior of the ducts themselves in attics where the Paston Effect is a problem. This was in an unusually humid South Florida attic.
When conditions such as elevated humidity, condensation, moldy AC ducts, sweaty AC ducts, mold, or mold odors, are detected in the attics of two story homes in coastal regions The Paston Effect may be the problem. This problem does not stay in the attic but often eventually spreads to the rest of the house.
This condition occurs when hot humid ocean breezes blows into the attic via soffit vents and causes humidity in the attic to rise and attic ductwork to reach dew point.
Excessive mold grows on the outer surfaces of condensation covered ducts ducts, this mold is almost always invisible to the untrained eye but occupants know their is mold because they smell mold odors or have allergic reactions or asthma attacks when in the house. Also Condensation will drip down from the sweating AC ducts and stain the ceilings below.
The moldy smelly attic air eventually gets worse and breezes blowing into the soffits causes the attic air to pressurize and enter habitable areas below. The moldy air escapes from the attic by blowing through hallow wall cavities below, and through wiring holes hidden above ceiling mounted light fixtures, or through holes hidden inside the housing of recessed lights and other openings including attic access covers.
Sealing these openings will not help because the problem will continue to fester and get worse in the attic.
Mold odor and moist air will eventually find it’s way out even through your electrical outlets and light switches where the condensation will form halos around light switches and outlets.
Whenever we have investigated homes with Paston Effect problems the homeowners have typically dealt with the problem for many years and have spent much money on non effective attempts to correct the problem.
Maintenance men, mold inspectors, AC contractors, and friends of the homeowners all have opinions and ideas on how to deal with this humid air problem creeping into the home from the attic but none seem to work.
Correction may not involve increased ventilation, because this might just let additional outdoor humidity into the attic. In addition it is more complex than simply sealing the attic as this may cause new problems.
In this photo we can see black colored mold on the exterior of a duct in an attic with the Paston Effect. Almost 100% of the time mold on ducts and in ducts is Cladosporium mold. The interior of such ducts is often mold as well due to humidity entrainment.
The solution is a multi step process that must be done correctly and tailored to your homes specific needs.
Correction will require professional inspections and consultation from a trained and qualified certified indoor environmentalist, engineer, or certified industrial hygienists who has experience investigating this specific complex issue. Question your inspector if he or she has no experience with this humidity problem then call someone else.
If your are experiencing any humidity, mold, attic condensation or AC duct condensation problems in the home, in the crawl space, or in the attic give Daryl Watters at A Accredited Mold Inspection Service a call. He deals with the Paston Effect and similar issue on a yearly basis.
For more online information on humidity control visit this page.
We have dealt with the Paston Effect and other types of humidity problems on large coastal homes and mansions throughout South Florida every year since 2003.
When experiencing the Paston Effect, Humidity Problems, moldy AC ducts or sweating ducts in your attic, and attic mold in hot humid climates we at A Accredited have the knowledge, experience, and connections with the right mold contractors to help end such issue in your estate home.
