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: February 20, 21, 28, and March 10 and 19, 2025
When discussing the concern with onsite staff, it was reported that a staff member was collecting their own indoor air quality data and readings were "high" for carbon dioxide (CO2).
An outdoor CO2 sample was collected was approximately 466 parts per million (ppm).
The space was vacant when the Office of the Environment arrived. The CO2 was approximately 1,500-1,700 ppm. However, very shortly after arrival, it decreased to between 500-600 ppm.
Carbon dioxide is used as an indicator compound to determine if sufficient outdoor air is being delivered to a space by the Heating Ventilation and Air Conditioning (HVAC) system. Typically, if CO2 is 700 ppm or more above the outdoor CO2 level for an extended period of time, this could suggest an issue with the delivery of outdoor air via the HVAC system.
The outdoor air dampers for HVAC unit that serves the space (AHU-6) were assessed. The outdoor air dampers were modulating between open/closed and appeared to be functioning properly. The modulation was due to the extremely cold temperatures that day (27.7 degrees Fahrenheit at time of observation). The modulation of the dampers prevents the coils from freezing.
It should also be noted that no carbon monoxide was detected in A23-A or A23-B (which is also served by AHU-6). Building Maintenance also assessed the boilers for carbon monoxide. Building Maintenance did not detect any carbon monoxide associated with the boilers.
As a precaution, the space was also checked for mold/moisture intrusion concerns.
No malodors were identifed.
Various surfaces were assessed for visible mold growth. No mold growth was observed.
Moisture measurements were collected in various locations to include drywall and wooden baseboards. No elevated moisture readings were detected.
No evidence of moisture intrusion, visible mold growth, or malodors were observed above the drop ceiling.
The supply diffusers were delivering air to the space.
Two stained ceiling tiles were observed.
Custodial cleaning practices appeared satisfactory, with the exception of some cobwebs in one corner of the space.
A mini refrigerator was observed in the classroom (energy management).
A data logger was placed in the space to measure CO2 during occupied hours. The data logger was collected on February 28, 2025:
- The highest CO2 reading during logging was 670 ppm, which is not considered elevated.
Custodial was requested to clean the cobwebs.
Custodial was requested to place work orders for the two stained ceiling tiles.
Removal of the mini-refrigerator was recommended to Administration to improve energy conservation.