Concern: Bollman Bridge Elementary School: September 4th, 2018 (CXBBES201800002C)

Date of IEQ Report Form
Date of Report
April 1st, 2019
A general health symptom was identified and believed to be associated with the room's Heating Ventilation and Air Conditioning.
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(s) of Assessment: June 27 and July 18, 2018

No mold growth or odors were identified.

No mold growth was observed behind the cove base assessed.

No thermal anomalies indicative of moisture intrusion were identified.

A return air grille is located in the room. The pressure differential within the plenum is positive (should be negative). The positive pressure differential is forcing air from above the drop-ceiling into the space via the return.

Air from the pressure differential is blowing against the edges of a ceiling tile possibly dislodging particles of ceiling tile (air erosion).

Aside from the pressure differential, the condition above the drop-ceiling was acceptable (no mold growth or odors).

Corrective Actions
July 18th, 2018

The ceiling tile edges boarding the return air grille were sealed by Building Services (HVAC), to prevent air erosion. This work was completed as a temporary measure while Building Services (HVAC) assessed the root cause of the pressure differential.

March 28th, 2019

According to Building Services (HVAC), the extreme pressurization above the ceiling is due to the restrictions in the return air path from spaces served by Roof Top Unit-2. Areas above the drop ceiling are packed with ductwork, piping, and wiring, limiting what can be done about the pressure differential. Due to this, the return air grille was removed and replaced with a ceiling tile to prevent return air from entering the occupant space.

Date Closed
Tracking Number