I hear the virus is airborne. What is the district doing about filtration?

West Irondequoit has engaged its architects and engineers to evaluate the HVAC system in light of COVID-19 and determined that the current system meets or exceeds state Code and SED guidelines. In addition, we have made several recommendations that we are implementing. They include:

Upgraded air filters installed throughout the district
Updating the HVAC operating software is taking place for better management and monitoring of the system.
Re-designing exhaust airflow from Health Offices to redirect outside.
Evaluate electrostatic filtration in specific high traffic areas.

(Updated below on Aug. 19)

How do I know the district’s ventilation (HVAC) systems are compliant with standards? Unlike other public buildings, school buildings and related mechanical infrastructure are under the oversight of the NYS Education Department Office of Facilities Planning (OFP). For decades, OFP has held high standards of air quality far above airports, malls, churches, etc. Of particular focus to OFP has been “make-up air,” which is the mixing of a ratio of fresh air to the tempered (heated/cooled) air coming into the classroom. OFP requires an extraordinarily high make-up air for schools. The OFP approves plans and specifications of HVAC system design prior to construction and it is usual for them to make significant costly changes or add scope to a project. OFP also reviews as built drawing and certification that the system is work as designed or better, far exceeding any other entity.

What is Fresh or Makeup Air and what does it mean in our buildings? Makeup air is introduced through HVAC systems to provide Code and OFP required ventilation. The quantity of makeup air is determined based on the size of the room served by the specific system and the maximum number of occupants within the space. In general, most HVAC systems are designed to introduce 20%-35% of makeup air in relation to their total airflow capacity. The outside air change rate for a typical classroom is approximately 3-4 times per hour.

How many air exchanges per hour does the ventilation system provide? “Air exchanges per hour” is not a term used in K-12 building design. The ventilation rate and overall airflow rate are determined as a function of the occupancy and square footage. The term “air exchanges” is used predominantly in healthcare, and it is based on how the requirements are presented in healthcare codes and standards. The Code does not dictate air change rates for educational systems. We can calculate these values, but the Code-required calculations are based on room square footage and occupancy. A typical classroom application, the outside air change rate is 3-4 times per hour.

Why are other public buildings NOT subject to these high standards? It is very inefficient system, with high-powered fans, heat pumps, etc. Think of a winter day when it’s 20 degrees and 25 mph wind outside and how hard your home furnace works to keep your home at 68 degrees. What do you think would happen to your furnace if you asked it to keep your home at 68 degrees and 40% of the air you were feeding it was 20 degrees that needed to be heated to 80 degrees or more so you could get sufficient heat through the ductwork and into your rooms? That is precisely what the schools systems are being asked to do. It is extremely energy inefficient, systems are costly because they are oversized and work harder and so useful life is shorter. Buildings are designed to the applicable Codes at the time of design. Codes have changed significantly over the past 50-plus years, with current Codes requiring more ventilation air than previous requirements. Older buildings may not have required any mechanical ventilation but the research of the benefits of improved indoor air quality has caused changes in modern codes/standards.

Can the District just upgrade its filters? Per the OFP, we already have OFP approved and code compliant filters with many areas at the maximum. Remember OFP approves our system design and the filter is just one variable in the air quality formula. The OFP has determined the current systems and operation meet or exceed required Code. The NYSED Re-open Guidance Document cautions districts on upgrading filters or modifying system design or operating specifications because they are not approved by OFP, the filters will likely reduce air flow, stress the HVAC systems to the point of being inoperative, thus causing a far more concerning air quality result. Our systems use a MERV 8 filters based on evaluations by engineers they determined it would be safe to move to MERV 11 filters. To increase beyond a MERV 11 filter will negatively impact performance of the equipment. Changing filters to MERV 13 or higher will result in increased static pressure and a decrease in overall performance.

How does the District know if the systems are working properly? Through the capital projects over the last 20 years, the District installed and upgraded the Direct Digital Controls (DDC) of our HVAC systems that allow us to continually monitor and adjust the systems, and also allows for remote access. We are currently in the process of updating software and some control hardware so even more can be adjusted and monitored with warnings and alarm capability to Buildings and Grounds.

If the air quality is “compliant” why is my room uncomfortable or I feel little/a lot of air coming out of my vents? Temperature is not the same as air quality and a balance of filtration and makeup air. Too much of one will lessen the other. Ventilation compliance is not indicative of proper temperature control or the amount of air delivered to a space. Correct air quantity does not mean the vent needs to be blasting air, or a lack of flow does not mean insufficient air is getting to your room. The amount of supply air into a room, depending on the system type, varies based on maintaining the room setpoint temperature. If a room is uncomfortable, or not maintaining the setpoint temperature, heating and/or cooling adjustments may be required. These changes are independent of the ventilation air quantity.

I work in an interior space with no windows, is that a compliant location? Yes. The OFP is extremely particular of such spaces, especially if the utilization includes students. The same standards apply and the HVAC system is designed, and we have confirmed, meets or exceeds design specifications.

If a hallway does not have mechanical ventilation system in the corridor, how does the air get recirculated? The overall ventilation quantity within a building is based on the number of occupants at full occupancy. The central air handling systems provide the required ventilation air during all occupied hours of the day. This is referred to as mechanical ventilation. The ventilation air is not directly introduced or recirculated within the corridors, but the corridors are open (and interconnected) to exterior doors, which provide natural ventilation. With classroom doors open, either during class sessions or between academic periods, the ventilation air in the classrooms will migrate to the corridors. At the time of design and construction of the high school, the HVAC systems met the applicable Codes and Standards, and the designs were approved by the NYS Education Department.

Can I bring a portable HEPA filter air purifier in to use in my classroom or workspace? In theory, the High Efficiency Particulate Air (HEPA) filters are known for removing dust, pollen and bacteria from the air. Equipment with the proper filter to capture the COVID-19 virus can be effective. Evidence-based claims of effectiveness and unit sizing for the square footage of the space is critical. What makes this question hard to answer is we don’t know how effective the HEPA air purifier will be, and most importantly, how do we assure that air will not be blown from one person onto another. CDC states, make sure fans do not blow from one person onto another as this will potentially transfer the virus. We are not encouraging staff to use their own air purifiers.

West Irondequoit Central School District

FAQ's: Reopening 2020-21

West IrondequoitCentral School District

West Irondequoit
Central School District

West Irondequoit
Central School District