Concern: Centennial Lane Elementary School: August 22nd, 2022 (CXCLES2022000237)

Location
Room 111
Date of IEQ Report Form
Date of Report
Concern
Mold on ceiling
Ceiling tiles warped and bowed due to moisture
Very humid and moist in room
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: September 12 and 19, 2022

The temperature (74.9 degrees Fahrenheit) was acceptable. 

The relative humidity (85.6%) is considered elevated and does not meet general comfort parameters and represents a concern for mold growth. 

Surfaces were assessed for visible mold growth and none was observed on the surfaces assessed during either visit.

No moisture was detected in the carpet.

The ceiling tiles were bowed which is an indicator of elevated humidity. 

Roof Top Unit-10 (RTU-10) was assessed by Building Maintenance (HVAC):

  • The sensor calibration was slightly off. 
  • The filters were in good condition.
  • The outdoor air screen was slightly dirty.
  • An issue was identified with the outdoor air dampers.

Building Maintenance (HVAC) reported that RTU-10 (only services Room 111) is a constant volume unit. This means that a constant volume of air is continuously supplied to the space during scheduled hours of operation, regardless of the humidity of outdoor air. HVAC systems are to introduce a certain percentage of outdoor air, per code. Constant volume systems are not ideal for humidity control and tend to deliver elevated humidity under certain weather conditions (outdoor temperatures in the 70's with outdoor humidity high (greater than 70%). This is because the outdoor temperature is similar to the indoor setpoint temperature and air conditioning is not prompted. The air conditioning is what provides dehumidification.  These weather conditions can present themselves in late August and in September.

Corrective Actions
September 19th, 2022

In the short-term, to improve humidity control Building Maintenance (HVAC) added controls for intermittent fan operation, damper control, and humidity sensors. In the long-term, Building Maintenance (HVAC) will be making upgrades to the dehumidification sequence of the unit (currently planned for the Summer of 2024).

September 28th, 2022

A moldy ceiling tile was not observed during the visit. If one is present, it can be replaced. A work order should be placed for Building Maintenance to address the cause of the moisture intrusion. 

Closed
Yes
Date Closed
Tracking Number
CXCLES2022000237