Concern: Oakland Mills High School: August 26th, 2021 (CXOMHS20210001E2)

Girls locker room office
Date of IEQ Report Form
Date of Report
October 5th, 2021
Mold on superficial parts of ac and inside of the ac unit. Unit is over 20 years old.
IEQ Investigation Process

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)

Date of Assessment: September 8, 2021

Mold growth was observed on the supply fins of the wall-mounted HVAC unit. Mold growth was also observed deeper within the unit along plastic components. 

Additional surfaces were assessed (desk, chairs, cabinets, etc.) for relative humidity mold growth which can occur if humidity remains elevated for extended periods of time. No relative humidity mold growth was observed on surfaces.

No moldy/musty odors were identified within the space. 

A supply diffuser (located in the ceiling) was assessed qualitatively and is supplying air to the space. This diffuser supplies outdoor air (dilutes odor, carbon dioxide, etc.) to the office area via Air Handling Unit-10 (AHU-10). 

The temperature was slightly elevated at (82 degrees Fahrenheit). However, staff reported they turned the unit off due to the mold growth within the unit. 

The relative humidity was acceptable (62.3%).

One stained ceiling tile was observed within the space.

The mold growth within the unit maybe related to the cooling temperature of the unit. If the air is too cold in relation to the air within the space. This can cause condensation to form on surfaces and subsequent mold growth.

Corrective Actions
September 8th, 2021

The Office of the Environment spoke with Building Maintenance (HVAC) on September 8, 2021 and requested the unit be disassembled and cleaned. 

September 21st, 2021

Staff members are not to adjust the temperatures on the unit (76 degrees in the cooling season). Additionally, it is recommended that the office door remain closed when the unit is in use. During the cooling season, the warmer/more humid air within the locker room can migrate into the office (depending on pressure differentials) and contact the cooled air from the unit. The rapid cooling of the locker room air, can condense, causing subsequent mold growth within the unit.

September 21st, 2021

The Office of the Environment recommended that Building Maintenance improve the regular maintenance plan for wall-mounted units such as the one in question. This process is underway as Building Maintenance is currently surveying schools for the units to improve the management of the maintenance program. 

September 21st, 2021

Custodial is to place a work order for the stained ceiling tile if one is not already in progress. 

Date Closed
Tracking Number