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: September 26, 28, and 30 and October 1, 31, 2023
The assessment was completed in general accordance with the items above. In addition to those items, the following was also completed: placed data loggers in various spaces to measure carbon dioxide, collected carbon monoxide readings, collected measurements for Volatile Organic Compounds (VOCs), and inspected the ductwork associated with AHU-1.
To reduce the length of this report, only deficiencies identified in each room are noted. Each space associated with the concern is listed in "bold" along with the associated Air Handling Unit (AHU) or Roof Top Unit (RTU). No carbon monoxide or VOCs were detected at any time during the assessment. No elevated moisture readings were identified in wood or drywall.
Room108 (AHU-1)
Dust/debris (fiberglass) was observed above the drop ceiling. This debris is from a former roofing project.
Room 103 (AHU-1)
Minor dust was observed on the supply diffusers.
Minor settled dust was observed above the drop ceiling.
Room 106 (AHU-1)
Dust was observed on the supply diffusers.
Minor settled dust was observed above the drop ceiling.
Room 801 (RTU-11)
Non-issued HCPSS disinfectants and cleaners were observed under the cabinet.
Although not a deficiency, a bucket of soil was located in the classroom (assuming used for Science experiment). Soil naturally contains biological matter such as fungus.
Exterior Greenhouse (adjoins 801, no HVAC)
Flaking and peeling paint indicative of moisture intrusion was observed in the greenhouse area (outside of the classroom).
Additionally, the greenhouse has several wooden items within it. Since the greenhouse is unconditioned, mold growth is likely to occur on wooden items.
Room 210 (AHU-1)
A return vent was not located in the space. This may impact general circulation, however carbon dioxide readings taken between October 18 and 25 were not elevated. Circulation is likely occurring through pressure differentials from adjoining spaces.
Dust was observed on the supply diffusers.
Dust/debris (fiberglass/wood) was observed above the drop ceiling. This debris is from a former roofing project.
Room 805 (RTU-10)
Dust/debris (fiberglass/wood) was observed above the drop ceiling. The debris is from a former roofing project.
Room 270 (AHU-6)
Dust deposits were observed on the keyboard desks.
An unusual sound was heard above the drop ceiling that may be associated with a pneumatic line (HVAC).
Room 308 (AHU-2)
Evidence of water damage (staining) was identified under the sink. No elevated moisture or visible mold growth was detected/observed.
Dust/debris (fiberglass/wood) was observed above the drop ceiling.
Room 606 (RTU-1)
The supply diffusers were dirty.
Media Lab (AHU-6)
No deficiencies identified.
Room 701 (RTU-7)
A thermal anomaly was noted in the corner of the room (exterior wall). No mold growth or evidence of moisture intrusion into the occupied portion of the building was noted (i.e. no condensation or flaking/peeling paint). When viewing area from the outside, the thermal anomaly is located near a sealant joint. It is possible the sealant needs to be repaired.
Media Center
The media center and the Science Wing Addition (Rooms 801-809) are prone to elevated humidity under certain weather conditions (particularly in the Summer), due to the design of the HVAC systems associated with those specific areas. Mold growth as a result of an extended period of elevated humidity was identified in the media center, impacting wooden bookshelves. To mitigate this impact, Building Maintenance (HVAC) is to run the HVAC from 4-6PM in the Summer. Additional run times of the system would increase the risk of elevated humidity and subsequent mold growth. The Office of the Environment understands Building Maintenance (HVAC) made an accommodation and operated the HVAC system on a "normal" schedule during various parts of the Summer. The increased run-time of the system coupled with specific outdoor conditions (temperature/relative humidity/dew point dependent) are the likely cause of the mold growth identified in the media center. Modifications to the controls of the media center unit are planned to occur prior to the next cooling season. These modifications would improve the relative humidity within the space, regardless of outdoor conditions. Once these modifications are made, the media center should not experience elevated humidity and subsequent mold growth under normal operating conditions (barring an unforeseen mechanical issue with the system).
Science Wing (808 and 809)
Rooms 808 and 809 have been historically been impacted by elevated relative humidity and mold growth in the Summer. The Science Wing (Rooms 801-809) have HVAC systems that were designed similar to the media center system. Historically, Rooms 808 and 809 have primarily been the concern. Extremely minor mold growth was observed on a few science lab benches (under the bench, where students legs would go, enclosed on all sides but one). The HVAC systems were reported to be operating under the normal 4-6PM summer schedule. The cause of the mold growth likely occurred due to the type of HVAC system and lack of air flow in the "cubbies" where students legs go when working at the lab bench. It should be noted, that Building Maintenance (HVAC) had planned to upgrade the controls to the science wing HVAC systems this Summer (2023) but reported they did not perform the work due to certain parts not arriving.
Modifications to the controls of the Science Wing are planned to occur prior to the next cooling season. These modifications would improve the relative humidity within the spaces, regardless of the outdoor temperature. Once these modifications are made, the Science Wing should not experience elevated humidity and subsequent mold growth under normal operating conditions (barring an unforeseen mechanical issue with the system).
Assessment of Applicable HVAC Units
- AHU-1 - Holes were identified in the connection between the unit and the supply duct. These flexible duct connectors are currently being replaced.
- AHU-2 - Holes were identified in the connection between the unit and the supply duct.
- AHU-6 - No deficiencies identified.
- RTU-1 - The rubber insulation around some of the copper lines needed to be cleaned.
- RTU-7 - The rubber insulation around some of the copper lines needed to be cleaned.
- RTU-10 - Filter bypass was noted around the edge of the filters closest to the access door. Dust build-up was observed on the coils due to the bypass.
- RTU-11 - Filter bypass was noted around the edge of the filters closest to the access door. Dust build-up was observed on the coils due to the bypass.
Mechanical Rooms associated with AHU-1 and AHU-2
AHU-1 and AHU-2 are housed in separate penthouses, located on the roof. The housekeeping in the penthouses (not in the units) was poor. Additionally, the fiberglass insulation was deteriorating in several locations.
Cooling Tower
Biological growth was noted within the cooling tower (on roof).
Interior of Ductwork - AHU-1
Many of the classrooms reported in this concern were associated with AHU-1. AHU-1 is one of the original AHU's associated with the school. The Office of the Environment requested a Certified Ventilation Inspection (CVI) under the National Air Duct Cleaners Association (NADCA) review the ductwork in AHU-1 to determine if additional assessment may be needed in association with the ductwork in other location of the school and/or to determine if cleaning was needed. The report concluded that the ductwork "would not require cleaning" at this time. No suspicious fungal growth was identified within the ductwork.
Carbon Dioxide
Carbon dioxide can be used as an indicator compound to determine is sufficient outdoor air is being delivered to a space. Outdoor air is important to indoor air quality as it dilutes contaminants that are produced in the indoor environment, such as odors released from people and the natural off-gassing of building materials and furnishings. It is these other contaminants that lead to indoor air quality problems such as odors and "stuffiness." Carbon dioxide is not generally found at hazardous levels in the indoor environment and it is not an allergen.
Carbon dioxide was found to be slightly elevated in Room 606 (RTU-1_ for approximately 20 minutes on October 19, 2023 and approximately one hour on October 24, 2023. No other areas were found to have elevated carbon dioxide readings.
Mechanical Engineering Study
Building Maintenance (HVAC) utilized a third-party engineering firm to assess the HVAC systems that are associated with the buildings original construction. The following recommendations were made in regard to the ventilation systems:
- "All air handling units seem to have been properly maintained over the years and are in good condition, given that they are over 50 years old. However, they have far passed their service life and are presenting high levels of wear and tear. Therefore, we recommend that these units are replaced in lieu of retrofitting/repairing. Since the equipment has been maintained to such a level of care, they should still have several seasons of operation before they eventually fail."
- All Roof Top Units are still in good working operation and require minimal preventive maintenance work.
- Within the report, the Office of the Environment identified the following items that could have an impact on indoor air quality:
- AHU-1: Air leakage from unit and the supply and return air side flexible duct connectors are brittle and have holes.
- AHU-2: supply and return air side flexible duct connectors are brittle and have holes. Standing water due to slope of drain pan.
Additionally, the following items were identified that could eventually lead to a potential future environmental concern:
- AHU-2 - A floor penetration was not sealed. Should a large leak occur in the penthouse, water could more easily travel to occupied portions of the building below.
- AHU-1 and 2 - The condensate pans are corroding. Should the pans fail, water will more easily leak from the units, potentially impacted building materials.
- Boiler Room - Corrosion was observed on an incoming cold-water pipe. If the pipe failed, the mechanical room (and possible beyond) could flood.
General Conclusion
Following the identification of the mold growth in the media center and Rooms 808 and 809, the Office of the Environment performed a school-wide assessment for mold growth that would have resulted from elevated summer humidity. In addition to the rooms already noted, mold growth was also identified in Room 802 (less than a square foot). Room 802 has a similar HVAC system as Room 808 and 809. This system is also slated to be retrofitted prior to the next cooling season. No visible mold growth was identified in any other location within the school. Visible mold growth in the indoor environment could be a potential source of allergen exposure.
Regarding AHU-1 and AHU-2, in theory, the small holes in the duct connectors could potentially impact the amount of air being supplied to occupied areas. This could impact temperature control and potentially slightly reduce the amount of outside air being delivered to occupants in those zones. However, the carbon dioxide readings do not suggest an insufficient amount of outside air being delivered to the AHU-1 and 2 zones. With that being said, any potential reduction in outside air should be corrected in an effort to improve indoor air quality.
Fiberglass and wood debris was observed above the drop-ceiling due to a previous roofing project. Minor dust as a result of normal operations was also observed. This dust/debris would not be anticipated to have a significant impact on occupant indoor air quality assuming regular filter changes are occurring by the Office of Building Maintenance. No major filter deficiencies were identified during this assessment however bypass was noted in RTU-10 and RTU-11 (already corrected by Building Maintenance). With that said, settled dust and debris located in close proximity to return air intakes (also above the drop ceiling) has a greater chance of being entrained into the HVAC system. This has the potential to load filters at an increased rate, requiring increased filter changes. Should filter bypass exist it is possible some particulate could be distributed back into occupied areas.
The minor dust on the supply diffusers is very common in the built environment and is considered a housekeeping item (i.e. not anticipated to be a significant indoor environmental quality concern). Custodial Services is responsible for dusting the supply diffusers as needed.
RTU-11 - Adjust outside air dampers to allow for additional outside air.
General - It is recommended that the frequency of dusting the supply diffusers be increased. If diffusers cannot be adequately cleaned due to age, they should be replaced.
Room 270 - the sound above the drop ceiling was reported to Building Maintenance for assessment/correction.
AHU-2 Penthouse - Seal floor penetration.
AHU-1 and AHU-2 Penthouse - Replace deteriorating fiberglass duct/pipe insulation.
AHU-1 and AHU-2 - Replace flexible duct connectors to reduce air leakage.
AHU-1 and AHU-2 - Replace condensate pans.
RTU-10 and RTU-11 - Correct filter bypass and clean coils.
Media - A board-approved contractor cleaned/disinfected wood surfaces to include surfaces not impacted by mold growth (wipe down and High Efficiency Particulate Air (HEPA) vacuuming). Additionally, each book was removed from the bookshelf, assessed, and cleaned as necessary. The work was overseen by a board-approved third-party industrial hygienist. Multiple commercial HEPA air purifiers were operated in the work area during cleaning. This work was completed on October 1, 2023.
808, 809, and 802 - The minor growth observed in these rooms was cleaned/disinfected upon discovery. A precautionary clean was performed by the board-approved contractor since they were already onsite for the media center.