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 Assessments: Weekly visits during the summer prior to concern, October 4, 8, 17, and 18, 2019.
Prior to October 4, 2019 (general background and not specific to room 10).
Weekly proactive visits of the perimeter rooms of the school's two story portion were made during the summer to observe conditions for relative humidity related mold growth. The proactive visits stem from past summer humidity issues. As of October 18, 2019, mold growth was not observed on inspected surfaces within Room 10.
During the summer, as a preventive measure, outdoor air dampers in the rooms' ventilation unit were closed and the units were operated from 1 -3 p.m. The reason for this schedule is to reduce the amount of humid outdoor air introduced to the space.
The school was under phase 1 (3 phases total) of a systemic ventilation renovation to assist with past relative humidity issues in the two-story portion perimeter rooms.
The air conditioning (new chiller) was installed during the summer and then energized on August 10, 2019. Prior to this date, relative humidity readings were acceptable (below or low 60%). On the August 14 visit, relative humidity reached 70% and above for a couple of rooms.
As a result, Building Services placed data loggers to view relative humidity and temperature trends. Data between August 15 and September 17, 2019, indicated a temperature range of 68-72 degrees (too cool) and bouts (August 31 to September 6 and September 9 to 13) of relative humidity 70% and above. In general, relative humidity should be between 30-65% for comfort. Based on experience, the Office of Environment is concerned with continuous bouts (24/7 for ~ 10 consecutive days) of 70+% since this can increase the potential for mold growth.
Outdoor air dampers were put back in operation for the start of school for students.
Relative humidity can fluctuate due to weather and the operation of the ventilation system. The ventilation unit's fan continuously operates during occupied hours thus introduces outdoor air to dilute body odors. When the room's thermostat is satisfied (i.e. cooling), unconditioned (hot /cool / damp) outdoor air is delivered to the space. In general, the type of ventilation unit within the room is not efficient at removing moisture from the air. In addition, the original controls are pneumatic (air) and have been experiencing air leaks which may allow the unit to operate 24/7 or not adequately control the chilled water flow through pipes within the unit, thus influencing relative humidity within the room. This is why the school's ventilation system is under renovation.
Room 10 Observations
The room felt muggy and damp on the morning (~6:45 a.m.) of October 4. The room temperature was 72 degrees and 71% relative humidity.
A data logger was placed in the room from October 4 - 18. The weekend of October 5th experienced 70% relative humidity and 75% on October 7. The rest of the logging period was less than 60% and temperatures ranged between 67 - 69 degrees.
The condition of the unit ventilator was acceptable. The outdoor air dampers were open.
The exterior block wall and wood casework along the exterior wall did not exhibit signs of moisture concern.
The local exhaust was not working.
A fresh wet ceiling tile stain was observed. Condensate was forming on metal pipe hanger and a section of pipe insulation above the ceiling tile.
The unit ventilator was believed to be operating 24/7 based on site visits on October 8 (4:37 p.m.), 17 (5:00 a.m.), and 18 (5:00 a.m.). At these dates/times the unit ventilator was operational but should have been off.
On October 18. an air freshener / odorizer scent was detected within the room, but the source could not be readily located.
Building Services resolved the local exhaust by turning the exhaust fan motor back on.
Building Services repaired source of the leak causing the ceiling tile stain.
Building Services has been notified about the possibility of the unit ventilator (includes other rooms) operating beyond scheduled time. A control specialist will assess the situation.
The item producing the air freshener scent is to be removed. These devices can mask an odor of concern and / or be an irritant to others.
The unit ventilator is scheduled to be off typically an hour after the school day. Custodial staff responsible for cleaning this room should check in the evening if air is blowing from the ventilation unit (wall unit) any time after 6 p.m. Building Services is to be notified if the unit is operating after that time.