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)
Dates of investigation: September 7 and 12, 2018.
The roof top ventilation unit (RTU) serving the center section of the first floor was turned off by Building Services about a week prior to the investigation due to extreme moist (air) weather conditions. This was completed to assist with interior comfort, knowing the areas had fan coil units (FCUs) to cool the space. RTU was turned on, on September 11, 2018.
The supply air diffuser within the office (connected to the RTU) was closed.
The cleanliness of the FCU and RTU was acceptable.
Individual indicated the odor is reduced when the FCU is on and worse when the FCU is off. The on /off function is manually controlled. The FCU was set to low fan speed and high cooling temperature. A moist odor could be detected when initially turned on.
On the initial visit, a damp aroma could be sensed. However, an odor was not detected on the second visit before the operation of the RTU and FCU (early morning). An odor was not detected when RTU began operation and FCU off. A moist aroma was detected from FCU when turned on and expected since coils are laden with condensate (from day before) as a function of cooling air.
Mold growth was not observed on inspected surfaces within the office.
The area above the drop ceiling was in good condition (i.e. pipe insulation).
On September 12, 2018 at approximately 7:15 a.m., the office temperature was 72 degrees Fahrenheit and 64.7% relative humidity (Guidance areas were the same).
The carpet was dry as determined with the use of a moisture probe.
The supply diffuser was opened to allow the introduction of outdoor air via the RTU to assist with comfort and dilution of odors in general.
School administration is to inform staff not to turn on FCU for cooling. Building Services indicated the FCU is best used for supplemental heating. This will prevent an inherent moisture aroma (condensate forming on coils during air conditioning mode) from FCU or over cooling space which may change the aroma of materials and supplies within the office.