Cleaner and healthier indoor air achieved via energy recovery ventilation improves the health, cognitive function, productivity and wellbeing of school occupants
School buildings are extremely vulnerable to deficient indoor air quality (IAQ). This is especially true with improved energy-efficient air-sealing methodologies on the rise that not only trap in air but also numerous internally generated contaminants. The best way to enhance IAQ is with increased ventilation, but conventional HVAC systems waste energy and therefore lead to additional costs. So how can IAQ be enhanced energy-efficiently, cost-effectively and sustainably in order to support the health and wellbeing of school occupants? The answer is through increased and balanced ventilation via energy recovery ventilators (ERVs). Let’s take a look at why this is the case.
The Challenge: Deficient IAQ Threatens School Buildings
With buildings becoming increasingly air-sealed to improve energy efficiency, a consequence is a rise in deficient IAQ. This is a serious—yet often unnoticed—threat to occupant health, cognitive function, productivity and general wellbeing. Deficient IAQ is especially concerning because people are indoors about 90% of the time (the elderly 95%). Moreover, the Environmental Protection Agency (EPA) found that indoor air may be two to five times, and occasionally greater than 100 times, more polluted than outdoor air.
Schools suffer considerably from deficient IAQ. The EPA determined that the typical school has approximately four times as many occupants as office buildings for the same amount of floor space. This means that more carbon dioxide (CO2 )—which is considered an indoor air contaminant—is exhaled into the air. What’s more, the EPA found that about 50% of school buildings have problems linked to poor IAQ.
Further, experts agree that the primary transmission route of SARS-CoV-2, the coronavirus that causes COVID-19, is through the air. Thus, due to their high-occupant densities, schools are quite vulnerable to the spread of airborne viruses that can lead to deadly diseases. This is especially true in school transient areas where occupant density is at its peak.
Deficient IAQ has Many Adverse Effects on School Occupants
Deficient IAQ has numerous adverse effects on all indoor occupants. Specific to schools, these include:
Further, the EPA determined that schools are at particular risk of experiencing deficient IAQ due to insufficient maintenance of facilities and HVAC systems. The problem is even worse in older buildings that need constant upkeep, including the majority of U.S. schools. These facts are alarming considering more than 55 million school children and about three million adults in the U.S.—equaling 20% of the country’s population—enter the nation’s schools every day. And the average child spends about 1,300 hours inside a school each year, while teachers and other employees spend even longer.
Moreover, the onset of COVID-19 provided unique health challenges for school occupants, particularly from an IAQ perspective. For example, if the indoor air wasn’t ventilated sufficiently, airborne viruses could build up and cause diseases. Although children are less susceptible to serious illness from COVID-19, they can still suffer from long-COVID effects. Further, during the pandemic, many school children missed or delayed preventive care appointments, thus creating potential long-term health issues. Additionally, the pandemic may have worsened children’s mental health or exacerbated existing mental health issues.
Similar to SARS-CoV-2, another virus that spreads via droplets is Respiratory Syncytial Virus (RSV). There is robust evidence supporting its airborne transmission, thus deficient IAQ due to lacking ventilation can increase its spread.
The Solution: Energy Recovery Ventilation is the Best Choice for Enhancing IAQ
What’s the best way to provide cleaner and healthier air inside school buildings? The answer is increased and balanced ventilation. As long as enough controlled and filtered fresh outdoor air is coming in and stale indoor air is exhausted out, interior spaces will enjoy high-quality air. In fact, the American Lung Association states that proper ventilation is essential for keeping the air fresh and healthy indoors.
Further, to stop the spread of airborne viruses, cognizant authorities recommend a layered approach with increased ventilation at its core. For example:
Due to their high occupant density, cognizant authorities understand the risk posed by transient areas in schools. Standards, like increasing hallway ventilation by 60%, are being developed to raise outdoor air rates in these high traffic and transient locations.
However, increasing ventilation rates in schools can also lead to higher energy consumption and costs. Thus, how can IAQ be enhanced while also optimizing energy efficiency and cost savings? The best way is via energy recovery ventilation, which enhances IAQ while maximizing sustainability.
ERVs precondition the outdoor air coming in with the otherwise-wasted exhaust air’s heat and humidity. This leads to substantial reductions in energy and equipment costs. Consequently, the EPA states that “ERVs provide excellent opportunities for saving energy, controlling humidity and providing sufficient outside air to promote IAQ.”
Increased Building Ventilation Rates Bolster Occupant Health
In the post-pandemic new normal, a spotlight has been shown on the criticality of enhanced IAQ to safeguard occupant health. This can be achieved with greater amounts of fresh and filtered outdoor air that’s ventilated indoors. With increased ventilation rates, aerosols and other indoor air contaminants are continuously diluted, reducing the intensity of exposure.
In fact, ASHRAE recommended the following in its Epidemic Task Force Building Readiness Report: “There is potential that building operators could increase their systems’ outdoor air ventilation to reduce the recirculation air back to the space. The guidance indicates that this should be done, if it is the selected mitigation strategy for this system, as much as the system and or space conditions will allow.”
In addition, the market now demands buildings that are better for both occupant health and the environment. Standards are evolving to keep up, such as the forthcoming ASHRAE 62.1, Section 42P on “Enhanced Indoor Air Quality in Commercial and Institutional Buildings.” It’s still under review, but once approved it will recommend exceeding minimum building ventilation requirements for enhancing IAQ.
What’s more, several green-building certifications require extra ventilation over code. These include:
The Results: Enhanced IAQ Improves the Health, Cognitive Function, Productivity & Wellbeing of School Occupants
Enhancing IAQ energy-efficiently, cost-effectively and sustainably through energy recovery ventilation results in numerous benefits for school occupants. These include:
Schools are at tremendous risk of suffering from deficient IAQ. Indeed, with increased air-sealing methodologies on the rise, the quality of indoor air is getting worse. On top of that, the risks of low-level IAQ were only amplified during the COVID-19 pandemic as the consequences can be severely detrimental to occupant health.
By enhancing IAQ through increased and balanced ventilation, the benefits to school occupants are numerous. These include improved health, cognitive function, productivity, wellbeing and peace of mind knowing you’re safeguarded from airborne viruses and other contaminants. And this can all be achieved energy-efficiently, cost-effectively and sustainably through energy recovery ventilation.