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

Perceived indoor air quality in naturally ventilated primary schools in the UK: Impact of environmental variables and thermal sensation.

Indoor air quality (IAQ) in classrooms has a significant impact on children's academic performance, health, and well-being; therefore, understanding children's perception of IAQ is vital. This study investigates how children's perception of IAQ is affected by environmental variables and thermal sensation. In total, 29 naturally ventilated classrooms in eight UK primary schools were selected and 805 children were surveyed during non-heating and heating seasons. Results show that air sensation votes (ASVs) are more correlated to CO2 levels than to operative temperatures (Top ) during non-heating seasons and more correlated to Top than CO2 levels during heating seasons. The impact of Top on ASVs decreases with an increase in CO2 levels, and the effect of CO2 levels on ASVs decreases with increase in Top . The most favorable ASVs are given when children feel "cool" and have "as it is" preference. By keeping CO2  < 1000 ppm and Top within children's thermal comfort band, ASVs are improved by 43%. The study recommends that standards should consider the impact of both temperature and CO2 levels on perceived IAQ. Perception of IAQ also affects children's overall comfort and tiredness levels; however, this influence is more significant on tiredness level than that on overall comfort level

Learning to Chill: The Role of Design Schools and Professional Training to Improve Urban Climate and Urban Metabolism

The increased frequency of heat-related mortality and morbidity in urban environments indicates the importance of urban climate studies. As most of the world’s population lives in cities, the education of designers, planners and policy makers is crucial to promote urban sustainability This paper, firstly, focuses on the different factors causing the urban heat islands in large cities. Secondly, it considers how these factors are reflected in higher education programmes. Examples are shown from courses in UK higher education, explaining the common software tools used for simulating urban spaces, and student field measurements are drawn on to illustrate how urban climate studies are included in higher education curricula. Urban metabolism is used to conceptualise the main approach to systemic resource-use assessments and as a holistic framework to investigate the main drivers of the urban heat island phenomenon. To sum up, this paper reflects on the importance of training climatically-aware graduates from design schools

Occupants’ satisfaction in BREEAM excellent certified buildings

This paper examines occupants’ satisfaction of three BREEAM excellent certified buildings at Coventry University in the UK. Occupants’ satisfaction is evaluated against passive and active sustainable approaches used in these buildings to improve Indoor Environmental Quality (IEQ). This paper adopts a quantitative approach by running a seven-point rating scale questionnaire to obtain occupants’ overall satisfaction score in each building. A total of 180 occupants were surveyed to investigate occupants’ satisfaction of the thermal environment, indoor air quality, visual and acoustic environment during summer and winter. The results show that average satisfaction scores are towards the more acceptable part of the scale in BREEAM Excellent certified buildings. The sustainable approaches towards these buildings and applied passive and active techniques improve occupants’ satisfaction of Indoor Environmental Quality. It should be highlighted that Coventry University has improved its sustainability approaches towards its buildings over time, with newer buildings showing a higher level of satisfaction

Developing a design framework to facilitate adaptive behaviours

Adaptive behaviour has a significant impact on the quality of indoor environment, comfort, and energy consumption. Therefore, facilitating positive occupant behaviours will improve these three factors. The aim of this paper is to develop a design framework that can be used as part of the design process to facilitate adaptive behaviours. This paper reviews studies that focus on reasons behind adaptive behaviours, and implication of these adaptive behaviours on the built environment. This paper highlights that ‘Context’, ‘Occupant’, and ‘Building’ (COB) have the most influence on adaptive behaviours. However, in most cases their influence is not considered holistically. This study also illustrates that adaptive behaviour has implications for the quality of Indoor environment, level of Comfort, and Energy consumption (ICE). This paper introduces a framework consisting of three stages: (1) Evaluate the relation between COB and ICE factors with adaptive behaviours holistically; (2) Design building's controls for ‘environmental behaviours’, set-up strategies for ‘personal behaviours’, and find a balance between these two; 3) Monitor the performance of adaptive behaviours through Post Occupancy Evaluation (POE)

Association between Ambient Noise Exposure and School Performance of Children Living in An Urban Area: A Cross-Sectional Population-Based Study

16 pages Article disponible à l'adresse suivante : http://link.springer.com/article/10.1007%2Fs11524-013-9843-6International audienceMost of the studies investigating the effects of the external noise on children's school performance have concerned pupils in schools exposed to high levels due to aircraft or freeway traffic noise. However, little is known about the consequences of the chronic ambient noise exposure at a level commonly encountered in residential urban areas. This study aimed to assess the relationship between the school performance of 8- to 9-year-old-children living in an urban environment and their chronic ambient noise exposure at home and at school. The children's school performances on the national standardized assessment test in French and mathematics were compared with the environmental noise levels. Children's exposure to ambient noise was calculated in front of their bedrooms (Lden) and schools (LAeq,day) using noise prediction modeling. Questionnaires were distributed to the families to collect potential confounding factors. Among the 746 respondent children, 586 were included in multilevel analyses. On average, the LAeq,day at school was 51.5 dB (SD= 4.5 dB; range = 38-58 dB) and the outdoor Lden at home was 56.4 dB (SD= 4.4 dB; range = 44-69 dB). LAeq,day at school was associated with impaired mathematics score (p = 0.02) or impaired French score (p = 0.01). For a + 10 dB gap, the French and mathematics scores were on average lower by about 5.5 points. Lden at home was significantly associated with impaired French performance when considered alone (p < 10(-3)) and was borderline significant when the combined home-school exposure was considered (p = 0.06). The magnitude of the observed effect on school performance may appear modest, but should be considered in light of the number of people who are potentially chronically exposed to similar environmental noise levels

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

Evaluating assumptions of scales for subjective assessment of thermal environments – Do laypersons perceive them the way, we researchers believe?

People's subjective response to any thermal environment is commonly investigated by using rating scales describing the degree of thermal sensation, comfort, and acceptability. Subsequent analyses of results collected in this way rely on the assumption that specific distances between verbal anchors placed on the scale exist and that relationships between verbal anchors from different dimensions that are assessed (e.g. thermal sensation and comfort) do not change. Another inherent assumption is that such scales are independent of the context in which they are used (climate zone, season, etc.). Despite their use worldwide, there is indication that contextual differences influence the way the scales are perceived and therefore question the reliability of the scales’ interpretation. To address this issue, a large international collaborative questionnaire study was conducted in 26 countries, using 21 different languages, which led to a dataset of 8225 questionnaires. Results, analysed by means of robust statistical techniques, revealed that only a subset of the responses are in accordance with the mentioned assumptions. Significant differences appeared between groups of participants in their perception of the scales, both in relation to distances of the anchors and relationships between scales. It was also found that respondents’ interpretations of scales changed with contextual factors, such as climate, season, and language. These findings highlight the need to carefully consider context-dependent factors in interpreting and reporting results from thermal comfort studies or post-occupancy evaluations, as well as to revisit the use of rating scales and the analysis methods used in thermal comfort studies to improve their reliability

Aircraft noise, overheating and poor air quality in classrooms in London primary schools

The main source of ventilation in the majority of UK schools is windows. The occupants of the classroom (i.e. pupils and teachers) in noisy areas tend to shut windows especially during quiet activities (i.e. silent and lecturing activities) to reduce the effect on teaching of aircraft noise as well as other external noises. Closing windows has two negative impacts on classroom environments. Firstly it increases the likelihood of classrooms experiencing overheating in hot weather and secondly poor air quality due to the lack of sufficient ventilation in the building. Through objective and subjective in a number of schools using surveys, monitoring of indoor temperatures, and testing of air quality and aircraft noise levels it was concluded that those schools located in the vicinity of Heathrow Airport are more likely to experience overheating and poor air quality due to aircraft noise, which can subsequently have a negative impact on students’ achievements