Humidity poses significant challenges to communities situated along coastal regions where the influence of moisture-laden air from lakes and oceans is pronounced. Humidity levels are exacerbated in those regions once the warmer temperatures arrive in late spring and summer.
For schools, these high humidity levels can pose significant challenges. The School of Public Health at the University of Albany conducted a study and found that students are often exposed to conditions that are hotter than recommended, with relative humidity (RH) levels beyond the recommended range. The study indicated that this makes students more susceptible to illness, while also posing challenges to concentration, causing an inability to focus properly.
Whether grappling with excessively dry or overly humid indoor conditions, maintaining optimal RH levels is crucial for ensuring a conducive learning environment. According to the U.S. Environmental Protection Agency (EPA), in order to protect the health of students and provide comfort, the indoor RH should be maintained ideally between 30% and 50%.
Classrooms with higher levels of humidity leave the air clammy, leading to discomfort and fostering the growth of bacteria, mold, and dust mites. Poor ventilation intensifies these issues, resulting in foul odors and an uptick in allergens, triggering asthma symptoms and allergic reactions.
As heatwaves become more frequent, some schools are ill-equipped to deal with the effects of extreme heat and poor indoor air quality on students. Many schools in the U.S. have HVAC systems that have reached their useful lifespan, leaving some school administrators with the difficult decision of sending students home because it is just too hot indoors.
HVAC Challenges with Humidity
Addressing humidity challenges requires a multifaceted approach as there are other contributing factors to humidity in schools. HVAC systems play a pivotal role in enhancing indoor air quality, but by design, they inadvertently introduce moisture inside buildings from pulling in outside air.
While this influx of fresh air is essential for ventilation, it also introduces moist air into the building, intensifying humidity concerns. Microorganisms such as mold, fungi, and bacteria can grow rapidly on indoor surfaces when humidity levels are high over long periods of time. Inhaling or touching these particles may cause allergic reactions for people with asthma or allergies to mold. Long-term exposure to humidity can also damage furniture, wallpaper, paintwork, floors, and brickwork.
When humidity levels are high, a well-maintained HVAC system has to work much harder to remove the excess moisture from the air. This adds additional wear and tear to the system, which is why humid regions require a specialized type of unit.
Routine maintenance can preemptively identify and rectify potential sources of moisture entering classrooms. Improved ventilation systems, coupled with dehumidification, can help regulate indoor RH levels, fostering a healthier and more comfortable learning environment.
Ventilation and Dehumidification in Coastal Areas
Mechanical HVAC systems are the best way to ensure classrooms receive fresh, clean air. However, a key challenge lies in effectively treating the air while maintaining comfortable conditions for students.
While many HVAC units feature a single coil for outside and return air, this setup may not suffice in regions with high humidity levels. School facilities managers in coastal regions should consider HVAC systems with a dual coil/fan configuration for optimal performance. Some models are specifically designed to provide enhanced dehumidification capability in humid climates.
If upgrading to new equipment is not an option, school facilities managers should consider retrofitting existing HVAC equipment with dehumidification controls where compatible. Dehumidification controls allow facilities managers to adjust the amount of moisture in an area as humidity rises or falls outside.
Proper Filtration Helps Control Humidity
Ventilation and dehumidification solutions equip K-12 schools in coastal regions with effective means to address increased moisture levels in the air. However, it’s important for school facilities managers to acknowledge the significance of proper filtration as well. After treating and introducing fresh air into classrooms, proper filtration also plays a vital role in reducing the entry of particulates.
ASHRAE recommends utilizing MERV 13 filters where compatible. Moreover, many HVAC units can be retrofitted with additional protective measures, such as needlepoint bipolar ionization, which releases ions into the classroom through the ventilation system to filter airborne particulates effectively.
Maintain Comfort in Schools
By addressing the root causes of moisture-related issues, implementing robust ventilation and humidity control measures, and prioritizing proactive maintenance, schools in coastal regions can cultivate environments more conducive to learning.
School administrators should consider investing in proper equipment to combat humidity as a priority. Not only will this support a healthier environment for the occupants, but it prolongs the lifespan of the building and its furnishing—all essential for ensuring the health and academic success of students and staff alike.
Luke Babey is the key account manager for the IAQ division of Modine Manufacturing Co., a global thermal management solutions provider headquartered in Racine, Wis.