HVAC contractors are leaving money on the table: $122 billion to be exact. The federal government’s largest pool of funds from the American Rescue Plan was designated for public schools. The Rescue Plan infused schools with $122 billion to reopen. But despite the bounty of funding, school systems throughout the U.S. have spent less than 15% of what is available to them.

Eneref Institute examined one of the 1,859 New York City public schools to learn how American Rescue Plan funds were utilized. The Boys and Girls High School in Brooklyn was an early adopter of MERV-13 filtration for their numerous window air conditioning units. The NYC public school district is the largest in the U.S., with over one million students.

The Rescue Plan funds have not yet been spent for a variety of reasons. Some school districts are still spending funding from the Trump administration. Eneref Institute also found that a desire to make the money last slowed school’s spending.

The New York City Department of Education (NYCDOE) purchased the MERV-13 filters from Klearview Appliance. Klearview Appliance, a Brooklyn-based contractor, won the contract with the NYC Department of Education to install 110,000 MERV-13 filters, as well as window air conditioning units, for individual classrooms. The 79 contracts Klearview signed with the city, since August 2020, are worth a combined total of $1.9 million.

Howard Blady, owner of Klearview Appliance, explained the system even offers benefits during winter months.

“You can put it on fan mode to capture the virus and it’ll cost you a fraction of the money in energy. You’re only spinning the fan motor and you have MERV-13 filtration,” said Blady.

In August 2021, John T. Shea, chief executive officer for the Division of School Facilities (DSF), directed custodian engineers to install MERV-13 as replacements for existing air conditioner filters. Custodial staff, who regularly maintain the school district’s entire HVAC system, replaced the filters at 30-day intervals. To ensure against any leakage, the filters were installed using filter clips provided by Shea’s department.

All of the window air conditioning units installed in the Boys and Girls High School were manufactured by Friedrich Air Conditioning Co. Early in the COVID-19 pandemic, Friedrich recognized that their standard window and through-the-wall air conditioner lines were already built with the necessary headroom to expand their filtration from a MERV-6 to a virus-removing MERV-13.

Almost all window air conditioners sold in the U.S. are now manufactured in Asia. In order to fit a greater number of air conditioners onto shipping containers, Asian-manufactured units are built necessarily small, leaving little room for a more robust filter.

“You’ve got to get the packing boxes to a certain size because you don’t want to fit two-and-a-half boxes across your shipping container. You want to fit that third box,” explained Howard Blady of Klearview Appliance. “That’s not a concern for Friedrich. They just pack them on trailer-trucks,” he said. “That’s why their product makes sense.”

In Boys and Girls High School, the MERV-13 filters capture airborne respiratory viruses and trap pollutants. Many existing HVAC systems were designed using MERV-8 filters or less, yet MERV-13 filters are five times more effective at capturing respiratory droplets and reducing viral concentration. Asthma, too, is managed with better filtration because the condition is triggered by indoor exposure to allergenic irritants. Nearly one in 13 school-age children suffer from asthma in the US.

Outside air dilutes indoor airborne contaminants, which is why opening windows is recommended. However, the CDC suggests that while ventilation can reduce the risk of viral exposure, it will not eliminate risk. The Friedrich air conditioners in Boys and Girls High School are designed to allow some outside air to ventilate the classroom. At the same time, their MERV-13 filters limit the need for an overabundance of outdoor air, lowering the costs of heating and cooling from temperature differentials.

Both system performance and filter performance are considered in the design of a well-balanced air conditioner. A robust filter requires more air pressure, or power, to pull air through the filter. However, impeding the airflow can freeze up the system. Friedrich employs numerous technologies to protect the coils from a restrictive air flow, including forward curved blowers, the performance of the compressor and heat exchangers, the overall design, and the shape of the filter itself to physically fit for optimal performance.

“My question to Friedrich was, if we put this filter in, will it cut the cfm of the amount of air that it’s gonna move. And they said that it’ll be fine,” said Blady. “To me, it means that the customer’s not gonna call and say my unit is freezing up … that it’s working.”

To guarantee there is no leakage around the filtration system, the a/c units utilize a filter-holding mechanism with special gap fittings and notches that securely rest flush against the front coil.

Eneref interviewed members of the Boys and Girls High School staff and found few that were aware of the benefits the filter offered.

“I know about the filters because I’m friends with the custodian, but I don’t know if everyone else knows,” said Ieisha Borden, secretary to the principal of Boys and Girls High School. “It would make them feel like I feel — a little bit safer.”

Lavonne Gaston, parent coordinator at Boys and Girls High School, noted, “We talk about the cleaning and all those things with parents, but I think sometimes we don’t go into the air conditioning and those types of details with them.”