Concern: Oakland Mills High School: August 23rd, 2022 (CXOMHS2022000239)

Location
Media and 808 and 809
Date of IEQ Report Form
Date of Report
Concern
Mold growth was identified within the Media Center and Science Classrooms 808 and 809 during the school's annual IEQ Walkthrough.
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)
Findings

Date of Assessment: August 17, 24, and 25, 2022

Rooms 808 and 809

Both of these spaces are serviced by Roof Top Unit-8 (RTU-8) have historically been impacted by elevated relative humidity and subsequent mold growth. Due to this, a detailed assessment of numerous surfaces was conducted in these rooms as part of the IEQ Walkthrough. 

Mold growth was identified in one location per room (approximately 2-3 square feet per room). The areas were cleaned/disinfected upon discovery. 

During the Summer, HCPSS typically closes the outside air dampers of HVAC systems to reduce the amount of unfavorable (high humidity) outdoor air introduced via the ventilation system. Constant air volume HVAC systems like the units serving Rooms 808 and 809 are particularly prone to causing elevated indoor humidity in the Summer (depending on a variety of factors to include outdoor temperature, relative humidity, and heat load within the spaces). HCPSS typically closes the outside air dampers of HVAC systems to reduce the amount unfavorable (high humidity) outdoor air introduced via the ventilation system during summer operations (low occupancy). However, due to the pandemic the outside air dampers remained open. Additionally, the situation may have been exacerbated by the calibration of the temperature sensor. 

Media

This space has been historically impacted by elevated humidity and subsequent mold growth. 

The insides of certain bookcases (wood components) were impacted by mold growth.

Additionally, the books were inspected. A few leather-bound book covers (the outsides not the pages) were impacted by mold growth (less than 10).

Constant  air volume HVAC systems like the system servicing the OMHS media center are prone to elevating indoor relative humidity, particularly in the Summer. To limit mold growth as a result of elevated relative humidity, HCPSS typically operates the HVAC systems at certain times of the day (afternoon) and for a limited amount of time in the summer. The Office of the Environment understands the scheduling of this system was modified to accommodate Administrative staff of a nearby school which is under construction. Additionally, during the Summer, HCPSS typically closes the outside air dampers of HVAC systems to reduce the amount unfavorable (high humidity) outdoor air introduced via the ventilation system. However, due to the pandemic the outside air dampers remained open through summer operations. The cause of the mold growth was due to the open outside air dampers and an extended run-time of the HVAC system during the summer.

Corrective Actions
August 17th, 2022

Building Maintenance (HVAC) closed the outside air dampers for the remainder of Summer operations. The outside air dampers were re-opened on September 2, 2022.

August 17th, 2022

Building Maintenance (HVAC) is to set a re-occurring work order to close the outside air dampers to the media center and RTU-8 during summer operations, regardless of the status of the pandemic and coordinate with the school to keep the areas from being utilized during summer operations. Alternatively, Building Maintenance (HVAC) can consider installing portable dehumidification units into these areas during the Summer if they are required to be utilized, until a more permanent solution can be initiated.

The Office of the Environment understands that modifications to RTU-8 are planned pending funding.

August 25th, 2022

A board-approved restoration contractor cleaned/disinfected the book-shelves over the weekend of August 19-22. Additionally, the books were removed from the shelves and cleaned as a precaution. The Office of the Environment inspected the work after it was completed and noted some residual mold growth, particularly on the undersides of cabinets within the bookshelves. The follow-up cleaning was completed on August 25, 2022.

It should be noted that residual staining can be observed on a few of the fabric-bound books.

September 1st, 2022

Building Maintenance (HVAC) reset the temperature sensor for RTU-8.

Closed
Yes
Tracking Number
CXOMHS2022000239