THE RELATIONSHIP BETWEEN HUMIDITY AND INDOOR AIR QUALITY IN SCHOOLS

Indoor air quality differences were investigated among five schools with and five schools without active humidity control systems. The active humidity systems provided approximately 15 cfm/person of ventilation air, while the schools without the active humidity control systems averaged less than five cfm/person. The space humidity levels in varying widely without active humidity control, and rose to unacceptable levels during summer shutdown periods. Field data and modeling showed that if the schools without active humidity control systems were operated at ventilation rates above five cfm/person, >70% relative humidity levels might occur for extended time periods. This research showed the importance humidity control and adequate ventilation in schools for contaminant control, comfort, and energy savings. INDEX TERMS Schools, Humidity control, IAQ, Ventilation INTRODUCTION Schools are susceptible to developing indoor air quality problems, and the occupants -children -are more significantly affected than adults (EPA 1998). School facilities, by design, are densely populated, making the task of maintaining an acceptable indoor air quality more difficult than in many other types of facilities. Another consideration is that the sole purpose of a school facility is to foster the learning process, which is impacted directly by the quality of the indoor environment (Boone 1997). Bascom (1997) states that “schools are facing two epidemics: an epidemic of deteriorating facilities and an epidemic of asthma among children.” He notes that while clinicians are trying to instruct schools with environmental control measures for children with asthma, these clinicians have little information about the conditions and practical means in schools. The schools are ill equipped to receive the recommendations, assess their reasonableness, and effect the recommendation at a reasonable cost. He points to the need for a controlled indoor air quality research study so that effective indoor air quality plans can be developed and implemented. The US General Accounting Office stated that one in five schools in the US has indoor air quality problems (GAO 1995, 1996). According to the same studies, 36% of the schools surveyed listed HVAC systems as a “less-than-adequate building feature.” Numerous researchers have indicated that poor indoor air quality significantly affects human health and productivity (Samet, 1993 and Milton, 2000). * Contact author e-mail: charlene.bayer@gtri.gatech.edu Proceedings: Indoor Air 2002