Case Study: HVAC malfunction caused closet mold and high humidity
A Murfreesboro homeowner noticed something off about their home's air quality. The house felt uncomfortably humid, even with the HVAC running. Then they discovered visible mold growing in an upstairs closet.
They called an HVAC technician who found the problem: something in the system wasn't hooked up correctly. The malfunction had created persistently high indoor humidity—the perfect environment for mold growth. Even after the HVAC repair, humidity levels remained elevated, and the family wanted to understand the full extent of the contamination.
Air quality testing revealed the HVAC issues had created significant mold problems throughout the home. The living room showed 1,500 spores per cubic meter, while another tested area registered 2,100 spores—both well above safe levels.
The dominant species was Penicillium/Aspergillus, measuring 530 spores in the living room and a concerning 1,700 spores in the more affected area. Basidiospores were present at 690 and 110 spores, and Cladosporium registered at 160 and 210 spores.
The HVAC malfunction had been circulating mold spores throughout the entire home via the ductwork. What started as a closet problem had become a whole-home contamination issue, with elevated humidity allowing mold to establish itself in multiple locations.
Claro performed a comprehensive whole-home treatment to address both the visible closet mold and the airborne contamination that had spread throughout the property. The dry fog process reached into the HVAC system, ductwork, closets, and every hidden space where humidity had allowed mold to grow.
Post-treatment testing confirmed complete remediation: total culturable fungi dropped to just 13 CFU/m³. The dangerous Penicillium/Aspergillus concentrations that had dominated the pre-treatment results were completely eliminated, and all other mold species were reduced to undetectable levels.
With the HVAC system properly repaired and the mold contamination eliminated, the home's humidity levels returned to normal ranges. The family could finally breathe comfortably in their home again.
This case demonstrates how mechanical failures in HVAC systems can create perfect conditions for mold growth—and why it's essential to test and treat the entire home, not just the visible problem areas.
