Thermal Comfort and IAQ

Suarez-Lopez, J. R., Cairns, M. R., Sripada, K., Quiros-Alcala, L., Mielke, H. W., Eskenazi, B., Etzel, R. A., & Kordas, K. (2021). COVID-19 and children’s health in the United States: Consideration of physical and social environments during the pandemic. Environmental Research, 197(December 2020). https://doi.org/10.1016/j.envres.2021.111160 This paper examines five topics that affect children development and health during the pandemic. These five topics are: exposures to environmental contaminants and the built environment, changes in food environments, limited access to educational resources, changes in social environments and family stressors, and finally, social justice and racism. Among built environment and environmental pollutant effects, the article mentions how by staying more time in unhealthy homes, children may be exposed to more allergens and indoor air pollutants. Similarly, the article touches on the fact that school closures and isolation measures may have impacted children’s physical health through reducing the opportunities to play outside and develop physical activity. 144

Publication type: Journal Article Study type: Literature review

Morawska, L., Tang, J. W., Bahnfleth, W., Bluyssen, P. M., Boerstra, A., Buonanno, G., Cao, J., Dancer, S., Floto, A., Franchimon, F., Haworth, C., Hogeling, J., Isaxon, C., Jimenez, J. L., Kurnitski, J., Li, Y., Loomans, M., Marks, G., Marr, L. C., Yao, M. (2020). How can airborne transmission of COVID-19 indoors be minimised? Environment International (Vol. 142, p. 105832). Elsevier Ltd. https://doi.org/10.1016/j.envint.2020.105832 In this paper from 2020 the authors argued that at the time there was sufficient evidence to support the idea that engineering controls, such as enhanced ventilation and filtration are a key element to limit the spread of the virus that caused the Covid-19 pandemic. They argued that public buildings such as hospitals, offices and schools can use engineering controls along with administrative and controls and personal protective equipment can use this kind of strategies to limit the spread of the virus. Among their recommendations are increasing outdoor air exchanges, eliminating air recirculation, supplementing ventilation with portable air cleaners, and avoiding overcrowding. 145

Publication type: Journal Article Study type: Literature review

Mendell, M. J., & Heath, G. A. (2005). Do indoor pollutants and thermal conditions in schools influence student performance? A critical review of the literature. Indoor Air, 15(1), 27–52. https://doi.org/10.1111/j.1600-0668.2004.00320.x In this review from 2005, Mendell et al. studied the associations between HVAC system and building characteristics, and indoor pollutants and thermal

conditions with reduced attendance or impaired performance. They equaled attendance with performance stating that attendance might decrease performance directly. They found that the effects of IEQ on performance or attendance were likely to be mediated by thermal conditions and pollutants. HVAC, building characteristics influenced IEQ exposures in ways not fully understood, which may affect health, attendance, and performance. They did not find specific causal relationships on pollutants, thermal conditions and performance or attendance, as there was very little research available at the time. The review they had to include papers that referred to adults, to be able to get to conclusions, but research on this area has increased substantially ever since. This paper pointed out the lack of research on biological pollutants in scholarly writing at the time. Using a sound selection method, they were able to find that there was suggestive evidence on NO2 to decrease attendance, strongly suggestive evidence on the effects of pollutants on the performance of building occupants, suggestive, but non consistent evidence on low ventilation rates and reduced performance, and suggestive evidence on cleaning and health in adults. They summarized evidence of other individual links to health and performance or attendance, mostly related to respiratory illness and infections. 146

Publication type: Journal article Study type: Literature review Age or developmental stage: Children and adults

Riham Jaber, A., Dejan, M., & Marcella, U. (2017). The Effect of Indoor Temperature and CO2 Levels on Cognitive Performance of Adult Females in a University Building in Saudi Arabia. Energy Procedia, 122, 451–456. https://doi.org/10.1016/j.egypro.2017.07.378

In this intervention study from Saudi Arabia, they examined the effects of temperature and CO2 levels (600, 1000, 1800 ppm) on vigilance and memory tasks. They gave performance tests and neurobehavioral cognitive tests to 499 female university students in two classrooms. They performed a continuous performance test CPT as representative of attention task and match to sample MTS as a working memory task. Also, they used the BARS battery – Behavioral assessment and research system for the cognitive performance assessment. They manipulated CO2 and Temperature for five weeks for each exposure, and controlled for light, sound, and participants’ behavior, and controlled for other confounder variables. They found statistically significant effects between outcome conditions and 3 different temperatures (20, 23, 25 °C). Participants performed significantly faster at 25 and 23 °C relative to 20 °C. They found differences between of students from different ethnicity regarding learning and temperature preference. They found that AC at home influenced this preference. They also found significant deterioration of learning at 1000 to 1800 ppm compared to 600 ppm CO2. 147

Publication type: Journal article Study type: Quasi-experimental study Sample: 499 female university students Duration: Longitudinal. 5 weeks of exposures. Exposures were done always at the same time of the day.

Age or developmental stage: College age

Rivera, M. I. (2019). Indoor Environmental Quality in Chilean Classroom. September, 1–119. https://scholarsbank.uoregon.edu/xmlui/handle/1794/25257 This dissertation studied IAQ and thermal comfort in Chilean primary school classrooms. It studied differences in the physical conditions of public and private schools, the comfort expectations of students and teachers, and the differences in perceptions according to socioeconomic background. Nine free running classrooms were studied in Concepcion, Chile during the fall and winter of 2018. The study included 880 students 10 to 14, 80 teachers, who were surveyed twice a day. Other methods such as physical measurements, observations, interviews and statistical analyses were used too. The study found that the students were comfortable despite being outside the comfort zone and exposed to low IAQ. The study found a statistically significant difference in perceptions between students from different social backgrounds (p<0.001). 148

Publication type: Doctoral Dissertation Study type: Field study Sample: Nine schools. Phase one: 28 classrooms, 888 students and 58 teachers, phase 2: 11 classrooms, 333 students and 23 teachers Duration: Fall and winter Age or developmental stage: 6th through 8th grade (10 to 14)

Wargocki, P., & Wyon, D. P. (2007). The effects of moderately raised classroom temperatures and classroom ventilation rate on the performance of schoolwork by children (RP-1257). HVAC and R Research, 13(2), 193–220. https://doi.org/10.1080/107896 69.2007.10390951 This paper evaluates the effects of thermal and IAQ conditions on children schoolwork performance. Using a blind crossover quasi-experimental design with repeated measures, they evaluated the performance of 10 to 12 years old children during an intervention. The experiment consisted in the manipulation of the split cooling units in two school classrooms during the summer, by modifying the air temperature and the outdoor air supply rate. Classroom conditions were changed weekly and repeated one year apart. Student performance was assessed on the base of numerical and language-based tasks, and students’ self-reported environmental perceptions and symptoms were recorded. Reducing the air temperature in classrooms from 25 °C to 20 °C improved the performance of schoolwork performed by children in numerical, language, concentration, and logical thinking tasks in terms of speed at the p < 0.05 level. Similarly, increasing outdoor air supply from 5 L/s to 10 L/s improved children performance in terms of speed. No effects were shown in language-based tasks. 149

Publication type: Journal article Study type: Experimental study Sample: 23 students per classroom, 2 classrooms Duration: Blind crossover design, interventions 1 week at a time, seven exercises Age or developmental stage: 10 to 12 years old

Wargocki, P., & Wyon, D. P. (2013). Providing better thermal and air quality conditions in school classrooms would be cost-effective. Building and Environment, 59, 581–589. https://doi.org/10.1016/j.buildenv.2012.10.007 Authors review and summarize seven field studies they developed on how classroom conditions affect children’s schoolwork performance, including only mechanically ventilated schools. The review states that nowadays classrooms are usually reaching uncomfortable temperatures (above 20 - 22°C), as schools are allowing the outdoor air supply becomes very low to save energy. They found that this causes CO2 levels to exceed 1000 ppm during school hours, which in turn reduces children’s school performance by as much as 30%. In previous studies, improving ventilation rates from 3.0 L/s to 9.5 L/s, children improved the speed to developed language and numerical tests significantly. Also, the percentage of errors in the numerical tasks were significantly reduced. This means that doubling ventilation rates could increase schoolwork speed by 8%. Also, reducing air temperatures from 25 °C to 20 °C increased the performance in arithmetical and language tests significantly in terms of speed. Reducing the air temperature also decreased the number of errors. Therefore, decreasing the temperature by 1 °C would improve student performance in terms of speed by about 2%. They state that performance effects may be caused by distraction and discomfort, as well as the physiological effects of thermal discomfort. This environmental effect is greater on children than it has been found in adults. The authors conclude that a more sophisticated and sustainable approach to maintaining IEQ in classrooms is necessary to preserve student performance. 150

Publication type: Journal article Study type: Literature review Studies reviewed: 7 studies

Wargocki, P., & Wyon, D. P. (2017). Ten questions concerning thermal and indoor air quality effects on the performance of office work and schoolwork. Building and Environment, 112, 359–366. https://doi.org/10.1016/j.buildenv.2016.11.020 Authors make a case for the different ways in which thermal comfort affects performance in both office and school settings. Regarding schoolwork, they go over a series of studies where temperatures above 25 C or 27 C affected the performance of children in different kinds of tasks. Regarding IAQ, they make a case for ventilation rates mentioning field intervention experiments where they increased air supply rates, and children were able to develop common school tasks faster. They state that it has not yet been possible to determine if subjective acceptance of thermal discomfort would be sufficient to remove the direct effects of physiological responses to performance. After reviewing four large experiments comparing self-estimated performance with actual performance, they conclude that self-estimated performance is not a good indicator of actual performance. It may indicate however, an increase in dissatisfaction with working conditions. They consider pollutants coming from the occupants and from the materials of the building itself. To measure these, they use CO2 as an indicator of the concentration of all bio effluents. They identify six mechanisms through which thermal comfort affects cognitive performance in people: attention or distraction, motivation to exert effort, arousal, manual dexterity, neurobehavioral symptoms, and