Identify deficiencies that may impact IEQ and/or sources of odor concerns. Typically includes the following depending on the nature of concern, but not limited to:
- interview/questionnaire of concern individual(s)
- inspection above drop ceiling (condition of roof deck, pipe insulation, return air plenum)
- inspection of ventilation system (operation of variable air volume box and outdoor air dampers, check controls, measurements of carbon dioxide, temperature and relative humidity, sources near outdoor air intake, measure return and supply air volume, cleanliness of coils, liner and condensate pan)
- inspection of exterior
- inspection below drop ceiling (housekeeping, sink and floor drain traps, signs of past and present moisture concern via visual and/or moisture meter, mold growth, ensure connection of current and capping of abandoned sanitary vents, odorizers, excessive plants and fabric items, identify potential pathways, and measure volatile organic compounds, carbon monoxide, and lighting)
Dates of Assessment: August 14 and September 17, 2025
The Office of the Environment evaluated Rooms D117, D110, and the Health Suite bathroom following reports of visible mold. Additional assessments were conducted in adjacent areas, including Room D118, the Health Suite exam rooms, and Student Services spaces.
Room D117
Less than two square feet of visible mold was observed on the masonry wall near the HVAC return. The affected area was cleaned using a board approved disinfectant.
Environmental conditions were within acceptable ranges, with a temperature of 72.7°F, relative humidity of 56.8%, and a dew point of 56.5°F.
No thermal anomalies were detected on the affected wall or adjacent surfaces using an infrared thermal camera. Additionally, no visible signs of water intrusion were observed above the ceiling tiles.
Health Suite Bathroom
Approximately eight square feet of visible mold was identified on the masonry wall near the supply diffuser and on the drywall ceiling surrounding the diffuser. The affected areas were cleaned using a disinfectant.
Environmental conditions were acceptable, with a temperature of 71.0°F, relative humidity of 60.6%, and a dew point of 56.6°F.
Infrared thermal imaging did not reveal any thermal anomalies on impacted or adjacent surfaces. Moisture readings taken from the drywall ceiling around the supply diffuser indicated no elevated moisture levels.
D110
Approximately 30 square feet of visible mold was observed on the masonry wall and ceiling tiles near the HVAC returns. The affected areas were cleaned using a disinfectant.
Environmental conditions were within acceptable limits, with a temperature of 70.7°F, relative humidity of 61.4%, and a dew point of 57.0°F.
No thermal anomalies were identified on affected or adjacent surfaces using infrared imaging. No visible signs of water intrusion were observed above the ceiling tiles.
Adjacent Areas
Rooms adjoining the impacted areas, including Room D118, Health Suite exam rooms, and Student Services areas, exhibited acceptable environmental conditions. No thermal anomalies or signs of water intrusion were observed.
Data Logging
A data logger was installed in Room D117 on August 14, 2025, and retrieved on September 17, 2025. The data indicated multiple instances where relative humidity exceeded 70% during this period.
Findings
A board approved mechanical engineer was contacted to review the HVAC system for deficiencies in AHU-13 which services the areas identified with mold growth and areas previously identified with mold growth (see IEQ Concern Report CXHOHS2024000314 for more details).
The contracted mechanical engineer believes that the mold growth identified is attributed to the positioning of the dual temperature valve. The dual temperature valve was reportedly open 100% in cooling mode which can "overcool" the air and cause condensation around the supply diffusers.
The dual temperature valve position was changed when the system enters cooling mode.
Seasonal weather patterns with high relative humidity are no longer present. The Office of the Environment will place data loggers in August 2026 to determine if the positioning of the dual temperature valve corrected the concern.