The effects of building‐related factors on classroom relative humidity among North Carolina schools participating in the ‘Free to Breathe,Free to Teach’ study |
| |
Authors: | K. A. Angelon‐Gaetz D. B. Richardson D. M. Lipton S. W. Marshall B. Lamb T. LoFrese |
| |
Affiliation: | 1. Epidemiology Department, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA;2. North Carolina Division of Public Health, Department of Health and Human Services, Raleigh, NC, USA;3. Maintenance Operations Department, New Hanover County Schools, Wilmington, NC, USA;4. Support Services, Chapel Hill‐Carrboro City Schools, Chapel Hill, NC, USA |
| |
Abstract: | Both high and low indoor relative humidity (RH) directly impact Indoor Air Quality (IAQ), an important school health concern. Prior school studies reported a high prevalence of mold, roaches, and water damage; however, few examined associations between modifiable classroom factors and RH, a quantitative indicator of dampness. We recorded RH longitudinally in 134 North Carolina classrooms (n = 9066 classroom‐days) to quantify the relationships between modifiable classroom factors and average daily RH below, within, or above levels recommended to improve school IAQ (30–50% or 30–60% RH). The odds of having high RH (>60%) were 5.8 [95% Confidence Interval (CI): 2.9, 11.3] times higher in classrooms with annual compared to quarterly heating, ventilating, and air‐conditioning (HVAC) system maintenance and 2.5 (95% CI: 1.5, 4.2) times higher in classrooms with HVAC economizers compared to those without economizers. Classrooms with direct‐expansion split systems compared to chilled water systems had 2.7 (95% CI: 1.7, 4.4) times higher odds of low RH (<30%). When unoccupied, classrooms with thermostat setbacks had 3.7 (95% CI: 1.7, 8.3) times the odds of high RH (>60%) of those without setbacks. This research suggests actionable decision points for school design and maintenance to prevent high or low classroom RH. |
| |
Keywords: | Indoor air quality Relative humidity Schools Classrooms Building‐related factors Longitudinal study |
|
|