How to Improve Indoor Environmental Quality

The COVID-19 pandemic has school districts taking a fresh look at indoor air quality (IAQ). The disease we once thought to spread only through droplets, we now know also spreads through aerosols suspended in the air. This spells trouble for students and teachers in poorly ventilated schools needing HVAC upgrades, which is estimated to be 36,000 schools nationwide.

The good news is that school districts now have access to billions of dollars in ESSER funds to help clean up indoor air and protect against novel coronavirus spread, (as well as common respiratory illnesses that plague us every year, such as the flu).

But, focusing on improving indoor air pollution alone would be shortsighted. If we want to transform America’s schools into healthy environments where students are not only protected — but also thriving — a more comprehensive focus is needed.

The Four Pillars of a Healthy Building

Researchers have consistently found that students who learn in newer buildings outperform those who learn in aging facilities. This is because aging facilities typically have poor thermal comfort, ventilation, lighting, and acoustics — the four pillars of indoor environmental quality (IEQ).

Alone, each of these pillars is important. But when considered together, system upgrades can be designed to increase the productivity, health, and mental well-being of students and teachers in all schools — newer and aging alike.

IAQ

Improving indoor air quality to fight the spread of SARS-CoV-2 has been front and center, but it isn’t the only concern. Poor quality air leads to decreased learning and increased absences for a plethora of reasons: drowsiness due to carbon dioxide exhaled in over-populated/under-ventilated classrooms, allergies to mold, and adverse reactions to chemicals used in schools.

Strategies to improve IAQ include:

• Bringing in as much fresh, outdoor air as possible

• Testing and maintaining exhaust systems, and using them during occupancy and for two hours afterward to remove particles from the air

• Ensuring high-efficiency MERV filters in the HVAC system are sized, installed, and replaced at least as frequently as the manufacturer’s instructions advise

• Using portable carbon dioxide (CO2) monitors to verify how well air is circulating in classrooms and other spaces

• Using portable air cleaners that use filtration technology, such as high-efficiency particulate air (HEPA) filters

While all of the above can help, nothing beats an HVAC system designed to meet ASHRAE ventilation guidelines. Not only can such a system reduce airborne infectious aerosol exposure, but studies also show that students’ attention spans significantly improve as ventilation improves. 

Thermal Comfort 

Have you ever tried to divide a double-decker equation into a single story in a room sticky with heat and humidity? Many of America’s high schoolers have to do just that, which is concerning because there is a correlation between classroom temperature, humidity, and student performance. Cooler temperatures and modest relative humidity conditions increase a student’s ability to perform mental tasks requiring concentration, such as addition, multiplication, and sentence comprehension.

That’s why it’s important to engineer systems based on more than just square feet and occupancy. At Millig, we employ psychrometry, which takes into consideration the thermodynamic properties of moist air. It’s an extra step that helps us provide an outcome fine-tuned for thermal comfort and increased learning.

Lighting

Replacing fluorescent lights with LED reduces energy use, but designing lighting for human health is a bit more complex. Because poor lighting and glare can cause distraction, migraines, eye strain, and fatigue, it’s important to execute a lighting strategy that optimizes both energy efficiency and visual comfort.

• Color temperature: A recent study shows that ‘cool’ light improves learning, while ‘yellow light’ is better for relaxing; incorporating tunable LED lighting into the classroom gives teachers the ability to “turn up” or “turn down” light by desired activity and need throughout the school day.

• Daylighting: According to the US General Services Administration, an effective daylighting strategy appropriately illuminates the building space without subjecting occupants to glare or major variations in light levels, which can impact comfort and productivity. Strategically placed windows that utilize exterior shading and multiple glass types can evenly distribute daylight in the classroom while reducing direct glare.

• Zones: Adequately designed classrooms divide their spaces into lighting zones to allow for flexible lighting solutions that support specific activities with a calculated mix of luminaires and daylighting.

Acoustics

If you design for all of the above and your HVAC system clicks and hums, or your insulation doesn’t minimize sound transmission, you’ve created a new problem that will distract a child’s learning ability. That's why it’s important to take into account acoustics when remodeling. This means, adopting sound-absorbing materials and designing systems with noise control in mind. 

Paying for IEQ Improvements in your Schools

HVAC upgrades can be costly. But, the Coronavirus Response and Relief Supplemental Appropriations and American Rescue Plan (ARP) Acts provide $177.1 billion in ESSER II and ESSER III funding for schools to implement public health protocols and help fight the airborne spread of COVID-19.

Specifically, schools can use ARP funds for:

• Inspection, testing, and maintenance of current ventilation systems and approaches

• Purchasing portable air filtration units, such as HEPA air filters

• Purchasing MERV-13 (or higher) filters for your HVAC system and ACs

• Purchasing fans

• Repairing windows and/or doors so that they can open to let fresh air in

• Servicing or upgrading HVAC systems consistent with industry standards

• Purchasing equipment to run outdoor classes

• Purchasing carbon dioxide (CO2) monitors, air flow capture hoods, and anemometers for custodians and building personnel to assess ventilation

• Paying for increased heating/cooling costs due to increased use of heating/cooling systems

• Other spending that supports inspection, testing, maintenance, repair, replacement, and upgrade projects to improve the indoor air quality in school facilities, including mechanical and non-mechanical heating, ventilation, and air conditioning systems, filtering, purification and other air cleaning, fans, control systems, and window and door repair