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 Assessment: August 11, 12, 13, and 18, 2021.
Mold growth was not observed on inspected surfaces within the office.
The carpet was dry as determined by the use of a moisture probe.
An odorizer was sensed and observed. The individual removed upon request so the investigator could determine if any unwanted odors were present. No odors were detected the days after the odorizer was removed.
The exposed fins of the supply air diffuser had visible particulate accumulation.
The thermostat was set at 78 degrees and working. Investigator lowered the setting to 74 degrees. The relative humidity was acceptable (below 60%).
A portable air cleaner was present in a box. The air cleaner was a HEPA only which is an acceptable type. However, the Office of Environment does not recommend the use air cleaning devices.
Housekeeping was considered acceptable.
Carbon dioxide (CO2) measurements were collected to assist with assessing the ventilation components serving the office as to if adequate outdoor air was being provided. The guideline is outdoor air CO2 plus 700 parts per million (ppm). Various measurements were collected with outdoor air ranging between 430-479 ppm and the office ranging 477-572 ppm (office doors varied open/closed and 0-1 person in the office). CO2 measurements were within the guideline.
The office is served by a variable air volume box (VAV). The thermostat in the room controls the VAV box. A damper within the VAV box adjusts as the thermostat temperature is satisfied. Air to the VAV comes from an air handling unit (AHU) which also serves several other VAVs within a ventilation zoned area. AHU 1 and AHU 2 were both inspected. However, AHU 1 serves the office of concern.
A balometer was used to measure the air volume being delivered from the supply air diffuser. 200 cubic feet per minute (CFM) was being delivered when the VAV was trying to satisfy the thermostat. When the thermostat was satisfied (damper closed) the damper eventually closed providing 0 CFM. The VAV box has a relief damper which was functioning.
The outdoor air damper was open at its minimum position at the time of inspection. No malodors detected. Coils were considered clean. Mold growth was observed on the Armaflex sound liner (solid rubber like surface that can be readily cleaned) behind the blower/fan of AHU 2. The growth was cleaned/disinfected as best as possible at the time of the finding using a long handle and cleaning pad. Minor suspect growth was observed at the sound liner near a section of turning vanes. Any suspect growth was contained to blower section and supply duct containing Armaflex (~20 linear feet per AHU).
No concerns were observed in the plenum space (area above drop ceiling). A return air duct opening to the AHU is located above the office and was not obstructed with particulate buildup.
The air freshener was removed after individual learned of HCPSS IEQ guidelines not to use air fresheners because they can mask an unwanted odor and/or be an irritant or nuisance to others.
The VAV box was providing 0 CFMs when at the minimum setting. Building Services HVAC Shop is to evaluate and correct the operation of the VAV damper.
The supply diffuser had visible accumulation of particulate. Building custodial staff will be informed to clean the diffuser.
AHUs 1 and 2 will be cleaned as a precautionary measure towards the end of the cooling season by a Board of Education approved HVAC cleaning contractor. However cleaning will happen sooner should Building Services HVAC Shop be able to determine and resolve the cause of the mold growth on the lined supply air section of the AHU and duct work (20 linear feet).