Page 20 - School Planning & Management, January/February 2019

FACILITIES FRESH AIR: THE IMPACT OF HVAC SYSTEMS ON INDOOR AIR QUALITY
running. There is never enough time or money, and honestly, no one complains about excessive levels of CO2. In fact, for
the savvy HVAC tech, life is much simpler
if the default position for fresh air louvers
is effectively shut off, eliminating almost
all fresh air to the classroom. Introducing sub-freezing air combined with moisture from snow and rain can spell disaster for ex- posed coils and piping systems. Conversely, bringing in outside air during the summer months when most schools are unoccupied and do not require fresh air, subjects build- ings to high humidity, mold and mildew, and higher energy costs. With the exception of computer-controlled outdoor air louvers, which have their own special brand of issues, manually regulated fresh air intake louvers are not always easy to access, let alone adjust properly. Rather than climbing up a ladder to the roof and wrestling with louver systems that once opened may not close when the time comes, it makes sense to leave well enough alone. The result could be subjecting occupants of classroom spaces to less than optimal air quality to support the learning environment.
Concentrations of carbon dioxide in outside air average around 400 parts per million (ppm). Building codes require mechanical systems in schools to provide fresh air ventilation. ASHRAE standard 62.1 specifies a ventilation rate of 15 cubic feet per person (ages 5-8) in classrooms. The recommended level is reduced to 13 cfm/p for ages 9 plus. A normal level of CO2 gas inside of the classroom ranges between 750 to1,250 ppm. A fully loaded space without adequate ventilation can register CO2 con- centrations as high as 2,500 to 5,000 ppm.
Fortunately, once understood, it’s a problem that can be solved. Brian Caffrel, Energy manager with Building Clar-
ity states, “ASHRAE 62.1 has two main methods for ventilation design: First is the VRP (ventilation rate procedure) method, which is more prescriptive in nature. Second is the IAQ (indoor air quality) method that is more of a calculation-based approach.”
In the design of HVAC systems for schools,
his company takes a proactive approach
to complying with code requirements and insuring optimal air quality for students. Caffrel explains, “Using Dynamic air clean- ers we utilize the IAQ approach since we are actively removing contaminants from the air stream. This allows us to bring in less outdoor air for direct displacement, result- ing in a system providing superior indoor air quality and higher efficiency due to the lower amount of outside air required.”
School facilities, particularly older, less energy-efficient buildings require main- tenance and operations technicians to pay greater attention to fresh air ventilation. They are faced with an enormous variety of equipment ranging from outdated HVAC systems with literally no provision for fresh air exchange to state-of-the-art equipment that automatically maintains a balance between energy efficiency and air qual-
ity. It is not a simple task to balance best practices for energy efficiency with indoor air quality standards. The incorporation
of outdoor air often requires more energy to condition to comfort levels and few systems use Dynamic air cleaners reducing the need for outside air. In a perfect world, HVAC technicians should not only be well trained on the mechanical equipment controls that regulate fresh air, particularly inside of classrooms, but also the IAQ stan- dards that require technicians to maintain a balance between thermal comfort, energy efficiency, and indoor air quality.
However, even under the best of circum- stances expecting maintenance technicians to know when equipment has been adjusted properly in order to provide adequate indoor air quality is a game of chance. This is especially true in the absence of monitoring or data analysis of the breathing air in each classroom space. With modern technol- ogy, measuring CO2 levels in the classroom is as simple as measuring temperature or humidity. For example, CO2Meter.com out of Ormond Beach, Fla., has developed an easy to read sensor that can be mounted on the wall in every classroom for a little more than $100 per unit. Along with temperature
and humidity, it shows current readings
for CO2 in parts per million. Better yet, the unit is designed to log data over a period of time, allowing facility managers to make adjustments and balance energy manage- ment with optimal indoor air quality. In certain cases, when it is determined that existing equipment settings are incapable of providing adequate fresh air for all students and staff, monitoring data can be used at a higher administrative level to support more costly capital improvements within the district. It is relatively common for schools to report classroom conditions involving temperature, humidity, unusual smells,
etc. These concerns are associated with conditions teachers can easily detect by their senses. Without actually taking an accurate measurement, it is nearly impossible for teachers to recognize when CO2 levels are elevated and request adjustments to HVAC controls regulating fresh air ventilation.
All teachers and building staff should be made aware of the impact fresh air ventila- tion has on student performance. Morgan Morris, director of Marketing for CO2Meter. com emphasized, “Elevated CO2 levels in schools is a topic deserving more training and awareness. With education, school offi- cials would be more likely to monitor spaces and use their analysis to improve classroom conditions for students and teachers.”
Managing the levels of carbon dioxide in the classroom on a routine basis along with adjustments to mechanical equip- ment when necessary can improve student achievement. With emphasis on test scores playing a significant role in the perceived effectiveness of public education, it would seem any advantage should be worthy of consideration. SPM
>>Andrew LaRowe is president of EduCon Energy Inc. located in Winston Salem, N.C. He can be reached at alarowe@educonenergy.com. Mike Raible is founder and CEO of The School Solutions Group in Charlotte, N.C. and the author of “Every Child, Every Day: Achieving Zero Dropouts Through Performance-Based Education”. He can be reached at mkraible@theschoolsolutionsgroup.com.
20 SCHOOL PLANNING & MANAGEMENT / JANUARY/FEBRUARY 2019
WEBSPM.COM