Engineering Healthier Schools

Healthier School Environments: A COVID Legacy

By Kabi Pandey, PE, Vice President/ Director Institutional Projects, ACEC New York SCA Committee Chair

The COVID-19 pandemic made public health the number one priority, shining a light on the indoor environment’s impact on well-being. While health officials recommended a multi-pronged strategy that included mask mandates, surface sanitization and social distancing, experts ultimately agreed that better ventilation—supplying air to or removing air from a space for the purpose of controlling air contaminant levels, humidity, or temperature within the space—is key to reducing the risk of airborne transmission of any virus, including COVID-19.

The message was particularly urgent for the New York City School Construction Authority (SCA), with over 1,400 facilities serving more than 1 million children throughout the five boroughs—the largest school system in the country. The SCA mobilized a campaign to survey the condition of ventilation systems in its buildings and develop the most economic, efficient and sustainable action plan for each. All occupied spaces in every school, as well as Department of Education (DOE)-owned offices, were inspected and reported on from July, 2020 through March, 2021.


For the second time in a decade, Lilker engineers were among those called to action by the SCA in a time of crisis. The first was in the aftermath of Super Storm Sandy, when many schools suffered devastating flood damage to their mechanical rooms. In response to the current COVID pandemic, our team of 26 dedicated mechanical engineers inspected and delivered reports on 120 schools and 20 DOE buildings throughout Manhattan, Queens, Brooklyn and the Bronx. 

Under an extraordinarily tight timeframe, Lilker participated in preparing Ventilation Checklist spreadsheets for each building surveyed—on time and to an exacting set of reporting requirements—to identify which facilities needed repair, replacement or redesign of existing ventilation systems to achieve adequate air flow. Provisional measures, such as increasing outside air exchange via open windows and the use of temporary supply fans, were put into place while longer-term solutions are in progress.

Criteria for Proper Ventilation

In assessing ventilation and designing HVAC systems to current standards, the criteria is based on the number of air changes per hour (ACH) and the Minimum Efficiency Reporting Values (MERV) rating. MERV is a scaled rating of the effectiveness of air filters, designed to represent the worst-case performance of a filter when dealing with particles in three different size ranges. The current standard for adequate ventilation is a MERV 13, which captures 50% of particles 0.3 to 1 micrometers, 85% of particles 1-3 micrometers, and 90% of particles 3-10 micrometers. ACH, in the mechanical sense, refers to how many times per hour the air volume from a space is pushed through the filter. Mechanical systems in a school facility should achieve 2-3 ACH.

Work Underway

Currently, Lilker is working on new HVAC system design associated with COVID ventilation for 14 New York City schools, including approximately 50,000 sq. ft. building additions at PS 105X, PS 2Q, PS 206Q and PS 26Q, as well as a 65,000 sq. ft. ground up building for PS 320X. The new building for PS 320X and building additions at PS 2Q & PS 206Q are in the construction phase. Lilker Energy Solutions (LES) provided energy modeling for PX 320X, as well as PS 256Q.

As with many COVID-related issues, there is a silver lining to the increased focus on achieving better ventilation in the schools. Research has shown that better ventilation improves student performance both by lowering carbon dioxide concentration and reducing student absences due to illness.

We are very proud of the work we’ve done with the SCA over the years to make school environments healthier, safer and more productive for New York City’s schoolkids.

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