Does Your School Have Poor IAQ?
September 14, 2017
Nearly half of the nation’s school buildings have reported problems [1] related to indoor air quality (IAQ). Why does IAQ in school buildings matter? Numerous studies link IAQ to student health and performance and show it can impact productivity and concentration.
Poor IAQ in a school can mean many things: Classrooms where children have a hard time hearing the teacher due to poor acoustics, where temperatures climb above 90 degrees on hot days due to lack of air conditioning, or where poor filtration adversely affects a child’s focus and their health.
These issues become more prominent as buildings age. The average age of public school buildings in the United States is over 40 years, and school districts have an estimated $542 billion of deferred maintenance [3] in buildings and grounds nationwide. As deferred maintenance grows, equipment effectiveness decreases, resulting in high utility costs and poor IAQ.
Innovations in heating, ventilation and air conditioning (HVAC) systems can help schools create quiet, comfortable classrooms for students and teachers — while keeping efficiency in mind.
Addressing IAQ with technology
Fan coils, blower coils and unit ventilators — often referred to as terminal products — are used by many K-12 schools and colleges as their first line of defense in classrooms to create a proper learning environment. Innovations over the years have resulted in terminal products that now offer vastly improved performance to help schools achieve better classroom IAQ and acoustics.
One such innovation is electronically commutated motors (ECMs), which use advanced motor technology and provide performance advantages in chilled-water terminal products. These motors are well-suited for classrooms and other applications that require speed control in a variety of operating conditions.
Advanced ECM technology uses programmable motor speed to provide quieter performance in classrooms in addition to greater efficiency. The motors operate in constant-volume or variable-air-volume (VAV) applications. In variable-speed applications, the high and low speeds are set, allowing the motor to run at any rpm within the range. The motor operates at the lowest speed necessary to meet the heating or cooling load requirements and adjusts when the space load changes.
In some applications, ECMs can ramp up or down softly between speeds. The soft ramp capability allows for less-noticeable audible changes and a substantial decibel reduction, resulting in acoustics that are more favorable for listening and learning. Noise can be reduced by 8 decibels by using variable-speed systems versus constant-volume systems.
Better dehumidification is another benefit of VAV systems. Operating at lower speeds delivers colder, drier air to the space, which improves classroom IAQ and comfort.
Because classroom occupancy changes throughout the day, terminal units with ECM technology can be integrated with controls to deliver a single-zone VAV solution. Pairing terminal systems that use EC motors with advanced building automation systems (BAS) provides greater control and oversight. Working together, they can deliver up to 66 percent higher efficiency (compared to constant-volume systems), along with temperature stability, quiet operation and dehumidification.
Benefits in the classroom
New advancements in terminal technologies help schools address indoor air quality issues by providing lower sound levels and better temperature and humidity control than what was previously possible. Providing an environment that makes it easier for students to pay attention and learn — and for teachers to instruct — is critical to creating a high-performing school.
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[1] United States Environmental Protection Agency (EPA), 2014 National Center for Education Study
[2] State of our Schools: America’s K-12 Facilities, 2016, U.S. Green Building Council, 21st Century School Fund, Inc, National Council on School Facilities
[3] State of our Schools: America’s K-12 Facilities, 2016, U.S. Green Building Council, 21st Century School Fund, Inc, National Council on School Facilities