Developing a valid method to study adaptive behaviours with regard to IEQ in primary schools

Adaptive behaviour impacts the classroom's environment and the student's comfort. Therefore, a deep understanding of students' adaptive behaviour is required. This study aims to develop a valid and reliable method to realize how children in their late middle childhood (9–11) practise adaptive behaviours as a response to the classroom's Indoor Environmental Quality (IEQ). A self-reported questionnaire accompanied with an observation form is designed based on children's ‘here and now’ sensations, their cognitive and linguistic competence. Validity and reliability of the questionnaire were tested by running pilot and field studies in eight primary schools from July 2017 to May 2018. Through transverse sampling, 805 children were observed, and 1390 questionnaires were collected in 31 classrooms. Questions and responses of the designed questionnaire were validated by monitoring answer-process, non-participant observations, cross-checking questions and statistical tests. Validating process improved the wording of the questions and response categories and resulted in a questionnaire with a high and valid response rate. The reliability of the questionnaire was tested by measuring the variability and standard deviations of responses under similar conditions. To conclude, the study introduces a questionnaire and an observation form that should be used together to provide a valid and reliable method for studying adaptive behaviour of primary school children

Adaptive Behaviours and Occupancy Patterns in UK Primary Schools: Impacts on Comfort and Indoor Quality

To improve the quality of school environment and reach state of comfort, it's important that teachers and students take appropriate personal and environmental adaptive behaviours. Studies on adaptive behaviours are mainly focused on adults, especially in residential and office buildings while children's adaptive behaviours at schools are not largely studied. This paper has investigated adaptive behaviours, influential factors and their impact on comfort and indoor quality by doing field studies in 4 primary schools and 15 classrooms in Coventry, UK during July, September, October and November 2017 through observations, subjective and objective measurements. The results are derived from observations on around 400 students aged 9-11 and from more than 600 surveys. Results illustrate that students usually take personal adaptive behaviours after or before breaks, and the number of these behaviours increases during warmer seasons and in afternoon sessions. Students' decisions over appropriate clothing level is related to time of year, however, 27% of students could improve their thermal vote by taking off or taking on jumpers/cardigans. Some environmental adaptive behaviours like door operation are less related to climatic factors, however, window operation is correlated to indoor temperature (R =0.29) and outdoor temperature (R =0.35). Observations show that around 80% of all environmental adaptive behaviours are done by teachers, teacher assistants or on their request, which can provide conditions that are not comfortable for children. Therefore, it is important to facilitate adaptive behaviour of children to improve their comfort level

Children’s Thermal Comfort and Adaptive Behaviours; UK Primary Schools during Non-heating and Heating Seasons

This paper aims to study children's thermal comfort and related Adaptive Behaviours in UK primary schools. The study was carried out in 32 naturally-ventilated classrooms during Non-Heating (NH) and Heating (H) seasons. Alongside collecting environmental data, a self-reported questionnaire and an observation form were employed to record children's thermal comfort and adaptive behaviours. From eight primary schools, 805 children aged 9–11 were surveyed and 1390 questionnaires were collected. Children's Thermal Sensation Votes (TSVs), Thermal Preference Votes (TPVs) and adaptive behaviours were compared against temperature offset from comfort temperature by EN 15251 (Tdiff=Top-TC(CEN)). Results suggest that children's thermal comfort (TC(children)) is 1.9 K and 2.8 K lower than that for adults (TC(CEN)) during non-heating and heating seasons, respectively. Children have lower comfort temperature and higher sensitivity to temperature changes during heating seasons. This can be attributed to children's lower practice of personal behaviours and more consistent indoor conditions during heating seasons. The proportion of children engaged with personal behaviours is one-third lower during heating seasons. As indoor temperature goes above children's thermal comfort band, the proportion of children practising personal behaviours increases during non-heating seasons. Around 80% of window operation is carried out by teachers who have a higher comfort temperature than children

Energy and economic performance of rooftop PV panels in the hot and dry climate of Iran

Photovoltaic (PV) Panels, one of the more promising renewable energy technologies, are growing rapidly nowadays, especially in developed countries. However, these systems have not achieved public acceptance in some countries due to low energy efficiency and poor economic performance, especially in countries which are subsidized in energy tariffs. In this paper, the energy and economic performance of fourteen rooftop PV systems with the power of 5 kW in the hot and dry climate of Iran are assessed by monitoring the total annual energy production and simulation. The monitored data is used to analyze systems’ economic performance via Pay-Back Period (PBP), Net Present Value (NPV), Return of Investment (ROI) and Levelized Cost of Energy (LCOE). Results show that single array configuration systems have the maximum energy production while dividing the system decreases the production. Economic analysis shows that the average PBP is 11.6 years under actual price of electricity (0.21$), however it is 46.9–50.5 years under subsidized average tariffs. ROI values range from 2.6 to 3.2 with the average of 2.9 for actual prices. Under subsidized prices, the cash generated by investment cannot even offset the costs that the investment requires during its lifetime with NCF and NPV being both negative. Overall, the systems are not economically beneficial under subsidized average tariffs in Iran, which discourages private and public sectors to investment on these systems. Environmentally, each PV system can averagely reduce 500 kg CO2 emission in the first year of installation and fourteen of them can approximately reduce 1,613,900 kg of CO2 emission during life time of PV panels

The impact of indoor environment quality (IEQ) on school children's overall comfort in the UK; a regression approach

Indoor Environment Quality (IEQ) is grouped into four main categories: thermal comfort, indoor air quality (IAQ), visual and acoustic comfort. Individual aspects of IEQ are investigated to examine their impact on children's overall comfort in primary schools in the UK. This study has surveyed 805 children in 32 naturally ventilated classrooms during non-heating and heating seasons. This study has calculated the proportion of comfort votes by individual aspects of IEQ, predicted comfort votes by multilinear regression model and estimated the probability of having uncomfortable votes by binary logistic regression. Results of this study highlight that the proportion of uncomfortable votes should be kept below 10%. The developed multilinear model suggests that for a unit change in Air Sensation Votes (ASVs) and operative temperatures (Top), comfort votes change by 0.28 and 0.12, respectively. Developed multilinear and logistic regression models show that ASVs have a more significant impact on overall comfort than Top. To achieve acceptable comfortable votes and keep the probability of having uncomfortable votes below 10%, ASVs and Top should be kept within these limits: [ASV = very fresh and Top = 19–27 °C], [ASV = fresh and Top = 19–24 °C], and [ASV = OK and Top = 19–22 °C]. The ranges suggest that better perception of IAQ makes up for higher temperatures. It is advised to maintain individual aspects of IEQ, however, dissatisfaction with one aspect of IEQ does not necessarily result in overall discomfort unless that aspect is extremely unacceptable. Investigating the most influential factors on occupants’ comfort suggests which building controls should be prioritized for designers

Ventilation rates in naturally ventilated primary schools in the UK; Contextual, Occupant and Building-related (COB) factors

Indoor Air Quality (IAQ) in classrooms is assessed by CO2 levels and Ventilation Rates (VRs). Factors affecting VRs fall into Contextual, Occupant and Building (COB) related factors. This study investigates how VRs are affected by COB factors in 29 naturally-ventilated classrooms in the UK during Non-Heating and Heating seasons. Building-related factors classify classrooms with high or low potentials for natural ventilation, with 45% of classrooms having high potentials. Contextual factors including season, operative temperature (Top), outdoor temperature (Tout), ‘Top-Tout’ and air density can limit or increase VRs. Occupant-related factors classify occupant's good or poor practice of environmental adaptive behaviours. ‘Open area’ as a reflection of all COB factors is strongly correlated with ventilation rates. Results show that 12% and 19% of variations in ventilation rates are explained by open areas during non-heating and heating seasons, respectively. Findings highlight that to have VR of 8 ± 1.28 l/s.p during non-heating seasons and VR of 8 ± 1.07 l/s.p during heating seasons, average open areas of 3.8 m2 and 2 m2 are required, respectively. This difference can mostly be explained by temperature difference between inside and outside. Results show COB factors need to be considered holistically to maintain adequate VRs. Classrooms in which all COB factors are met provide average VR of 11 l/s.p and classrooms in which none of COB factors are met provide average VR is 3.1 l/s.p. This study highlights that 40% of classrooms according to EN 13779 and 80% of classrooms according to ASHRAE Standard fail to provide adequate VRs

Indoor Air Quality (IAQ) in Naturally-ventilated Primary Schools in the UK:Occupant-Related Factors

Indoor Air Quality (IAQ) is affected by Context, Occupant and Building (COB) related factors. This paper evaluates IAQ as a function of occupant-related factors including occupants' Adaptive Behaviours (ABs), occupancy patterns, occupant's CO2 generation rates and occupancy density. This study observed occupant-related factors of 805 children in 29 naturally-ventilated (NV) classrooms in UK primary schools during Non-Heating and Heating seasons. Occupant-related factors affecting IAQ include occupants' adaptive behaviours, occupancy patterns, occupants' CO2 generation rate and occupancy densities. Results of this study suggest that a classroom with high potentials for natural ventilation does not necessarily provide adequate IAQ, however, occupants’ good practice of ABs is also required. Average occupancy densities to have CO2 levels of 1000 ± 50 ppm are suggested to be 2.3 ± 0.05m2/p and 7.6 ± 0.25 m3/p. These values correspond to the classroom area of 62.1 ± 1.35 m2 and volume of 205.2 ± 6.75 m3 with a height of 3.3 m. Mean CO2 level is maintained below 900 ppm when all occupant-related factors are in the favour of IAQ, however, it exceeds 1300 ppm when none of the occupant-related factors are in favour of IAQ. It is shown that 17% of CO2 variations are explained by open area (m2), 14% by occupants' generation rates (cm3/s) and 11% by occupancy density (m3/p). IAQ is mostly affected by occupants’ adaptive behaviours than other occupant-related factors in naturally-ventilated classrooms