Next to personal, psychosocial and physiological aspects, environmental aspects of homes may affect the health and comfort of their occupants. This study aimed to investigate the multifactorial character of both rhinitis and headaches among five groups of students from universities in five different cities: Taichung (Taiwan), Concepcion (Chile), Paramaribo (Suriname), Beijing (China) and Delft (The Netherlands). Among the students studied, 18% declared having suffered from rhinitis in the last 12 months, and 30% from headaches in the last 3 months. Self-reported characteristics of 682 students and their homes were linked to self-reported rhinitis and headaches. Logistic regression modelling was applied to explore relations between building-related factors and rhinitis, and between building-related factors and headaches. After full adjustment, the regression model for both rhinitis and headaches confirmed their multifactorial character. While personal-related factors family rhinitis and age were associated with rhinitis, negative events and PANAS negative were with headaches. Biological pollutants (caused by pets) were associated both with rhinitis and headaches; chemical pollutants, caused by open bookshelves and lack of sweeping floors, were associated with rhinitis. The study concludes that the identified risk factors seemed independent of season or climate region.@en

Key performance indicators (KPIs) are quintessentially useful for performance evaluation, but a set of pragmatic KPIs for holistic evaluation of retrofits for commercial buildings is hitherto unavailable. This study was conducted to address this issue. Built upon the findings of a systematic literature review and a focus group meeting in the earlier stages of the study, a questionnaire survey covering 19 KPIs for environmental (embracing energy), economic, health and safety, and users’ perspective evaluations of building retrofits was developed. Data of the survey, collected from facility management (FM) practitioners in Hong Kong, underwent a series of statistical analyses, including Kruskal–Wallis H test, Mann–Whitney U test, and Spearman Rank Correlation. The analysis results revealed the levels of importance of KPIs perceived by different groups of FM practitioners and the rankings of KPIs. Based upon these results, eight KPIs were shortlisted, which are energy savings, payback period, investment cost, actual-to-target ratio of the number of statutory orders removed, actual-to-target ratio of the number of accidents reduced, target indoor air temperature, target indoor air quality (IAQ) class, and target workplane illuminance. These KPIs serve as keystones for further development of an analytic evaluation scheme for commercial building retrofit performance assessment. The methodology of this study can also serve as a reference for similar KPI studies in other research domains@en

Under current pandemic of COVID-19, children are still spending long hours in school classrooms every day. A literature study is therefore conducted to investigate the current ventilation strategies used in schools and assess their performance of controlling contagious respiratory diseases in the indoor environment, and also to seek for future solutions. Research papers, reports and standards relevant to school ventilation, airborne transmission and complementary air distribution methods are reviewed. It is concluded that schools usually have natural ventilation (NV) or mechanical ventilation (MV), however the overall indoor air quality is not ideal. Both NV and MV can reduce the airborne transmission of respiratory droplets efficiently when designed, operated, and maintained properly, yet schools are in shortage of informative standards and guidance. Personalized ventilation (PV) has a promising potential in protecting occupants from local indoor air contaminants, yet further studies are needed before PV can be applied to children in classrooms.@en

High efficiency air filtration has been suggested to reduce airborne transmission of ‘infectious’ aerosols. In this study the ‘air cleaning’ effect as well as the effect on sound and air velocity (draught risk) of a mobile High-Efficiency Particulate Air (HEPA) filter system was tested for different settings and positions in the Experience room of the SenseLab. From both the noise assessments by a panel of subjects and sound monitoring it was concluded that the mobile HEPA filter system causes an unacceptable background sound level in the tested classroom setting (Experience room). With respect to the air velocity measurements and draught rating calculations, it was concluded that both depend on the position and the setting of the HEPA filter system as well as on the position and height of the measurements. For the removal of aerosols simulated by air-filled soap bubbles in front of the subject, the mobile HEPA filter system performed better as compared to the ‘No ventilation’ regime, for all settings and both positions, and for some settings, even better than all the tested mixing ventilation regimes. The use of a mobile HEPA filter system seems a good additional measure when only natural ventilation options are available. Future research should focus on rooms of different sizes or shapes, as this may also play a role in the filter's performance, noise and draught effects.@en

A recently published simulation-based study has demonstrated the effect of an individually controlled noise-reducing device (ICND) on improving acoustic quality in classrooms. As a follow-up research, this current study aims to develop a real ICND and test it with its target users-- primary school children. The prototype developed in this study looks like a canopy hanging above a desk, was selected and prototyped. It has two modes, i.e. open and closed, and can be easily changed by a remote controller. With this device, school children can control their local acoustic environment by themselves. More than 200 primary school children have been invited to test two prototypes of this device in the acoustical chamber of the SenseLab. The results showed that 83% of the children liked this device and 61% of them wanted to have it in their own classroom. However, since this is a prototype, there is still room for improvement. Based on the children’s feedback, several suggestions for future modifications have been summarized.@en

Previous studies indicate that acoustic improvements at classroom-level, such as using ceiling panels, do not work well to solve noise problems in classrooms. Therefore, this study introduced a new way – individual control – to improve classroom acoustics. The acoustic effect of five different classroom settings is simulated: two individual-level acoustic improvement settings (“Single-sided canopies” and “Double-sided canopies”), two classroom-level acoustic improvement settings (“Half-ceiling” and “Full-ceiling”), and one “Control” setting. The simulation was accomplished with Computer Aided Theatre Technique (CATT-Acoustic™), which is a ray-tracing-based room acoustics prediction software package. According to the two main ways of using classrooms (instruction and self-study), the simulations were run for two situations: instruction situation and self-study situation, and the Lombard Effect was taken into consideration in the self-study situation. The results showed that in both situations, all of these improvement settings, compared with the “Control” setting, could shorten the reverberation time and increase the speech transmission index, and the improvements caused by the individually controlled canopies were more obvious than caused by the ceiling panels. Additionally, in the instruction situation, the individual-level improvements could increase the sound pressure level of the teacher's speech, while in the self-study situation, the individual-level improvements could decrease the sound pressure level of other children's talk. In the future, it is recommended to produce and test different individually controlled devices in a lab or real classroom to verify these results.

@en

People spend around 90% of their time indoors, where they are exposed to various physical stressors, such as unpleasant sounds, odours, temperature, and lighting, which may cause annoyance and discomfort. This literature review is focused on substantial studies that emphasize noise as a physical stressor in the indoor environment. Previous studies showed that background noise has a significant impact on human health. Adding to that, several other studies showed significant cross-modal effects between noise and other environmental stressors. However, various previous studies focused on quantifying the indicators of the indoor environmental quality (IEQ) factors rather than studying the differences of each occupant on their preferences and needs. Hence, this literature review highlights studies that take into account the interaction effects of acoustics at and between human and environmental levels. This review study aimed at identifying the key indicators to be taken into account for evaluating acoustical quality.@en

Literature shows that both building systems and occupants’ behaviour contribute to the amount of energy used to create a comfortable indoor environment. To determine possible relationships, energy consumption of nine school buildings was studied in relation to identified building characteristics, self-reported frequency of teachers’ actions, and (perceived and measured) indoor environmental quality (IEQ) of the school children in the classrooms studied. These schools were located in different areas in the Netherlands, and their yearly energy consumption differed a lot. Results demonstrated significant relationships of electrical energy consumption with lighting distribution in classrooms and the frequency of teachers’ light switch behaviour: the higher the measured illuminance in the classrooms, the more electricity was used in the school building. The more electricity was used, the more children complained about the IEQ in their classrooms; and the more frequently the teachers turned on the light, the less electricity the schools consumed. It was concluded that stimulating teachers to be more active in controlling the light might lead to energy saving, but a larger sample of schools with more variation in buildings systems is required to confirm this.@en

It is well-known that the indoor environmental quality (IEQ) at schools affects the health, comfort and performance of school children. Considering the need for a more effective way to improve both the IEQ in primary school classrooms and children’s satisfaction, along with the positive potential of individual control, this thesis aimed to propose a new way - individual control - to improve the IEQ in classrooms of primary schools and to increase children’s satisfaction in the Netherlands. First the main IEQ problem in classrooms as well as IEQ perceptions and preferences of the school children were identified through literature and field studies. The outcome showed that noise was the main IEQ problem in classrooms of Dutch primary schools, children could be clustered in according to their IEQ perceptions and preferences, and the reported IEQ-improving actions of the teachers could not effectively improve the IEQ for each child. As a follow-up, lab studies were performed in the SenseLab to explore the effect of background sound on children’s sound perception and performance. Together with the outcome of the field studies, results suggested that individual control is a better way to improve IEQ in classrooms. Therefore, to address the main problem – noise - in classrooms, an individually controlled noisereducing device was designed, prototyped and tested with school children in the SenseLab. The results obtained from the simulations, measurements, and children’s feedback on the prototype of the device, demonstrated the feasibility of such devices in classrooms at primary schools. @en

Our sensory system (nose) could predict the perceived odour intensity of various materials relatively well and in many cases the nose seems to be a better receptor of pollutants than some equipment. To test this ability with children, odour tests were performed as part of a study performed with 335 primary school children in the air quality test chamber of the SenseLab. Two similar experiments were conducted to assess the identification of potentially recognizable odours for children. The different sources of odour were placed in different containers and the children were asked how they feel about the smell and to identify the source of smell. There were statistically significant differences among children’s evaluations of different smells and it was difficult for them to identify certain sources of smell.@en

Background: It is well-known that indoor environmental quality (IEQ) in classrooms can have an effect on school children's comfort, health and performance. Unfortunately, information about the school children's perception of IEQ factors in their classrooms is still insufficient. The objective of this study was to better understand school children's IEQ preferences and needs in classrooms. Methods: Perceptions, preferences, and needs regarding the IEQ in classrooms were collected by a questionnaire from 1145 school children (9–12 years) in 21 primary schools (54 classrooms) in the Netherlands. Descriptive analysis, correlation analysis, principal component analysis and two-step cluster analysis were used to analyse the data. Results: Using two-step cluster analysis, this study identified six clusters (profiles) of children based on their comfort perceptions and the importance of environmental factors. Among them, four clusters of children had specific concerns related to the IEQ factors: the ‘Sound concerned cluster’ the ‘Smell and Sound concerned cluster’ the ‘Thermal and Draught concerned cluster’ and the ‘Light concerned cluster’. However, the other two clusters of children did not show a specific concern, the ‘All concerned cluster’ was concerned about all IEQ factors in the classroom, while the ‘Nothing concerned cluster’ did not show any concern. Conclusion: This study allows for a better understanding of the preferences and needs of primary school children from their own perspective and provides a foundation for future studies to improve both the IEQ in classrooms and school children's comfort and health.

@en

To investigate whether different colours of the indoor surfaces could have an effect on thermal comfort of children, 335 primary school children were invited to take part in a series of tests conducted in the thermal test chamber of the SenseLab. A three-way factorial randomized design was used to test the effect of three different colours of walls (white, red and blue) and floor (grey, green and blue) on the temperature and draught feeling in a winter situation (sunlight coming in: heat) and a summer situation (opening window: draught). A statistical relevant relationship between feeling of draught and feeling of temperature was found. Except for a significant difference in temperature feeling for different floor colours when the wall colour was red in the winter situation, no relevant effects (or interaction effects) were found for differences in wall or floor colours on the temperature or draught feeling.@en

The acoustic conditions of classrooms received a lot of attention in the last decades because of its important role in school children's comfort and performance. In a previous field study of 54 classrooms from 21 schools in the Netherlands, more than 85% of the 1145 primary school children reported that they were bothered by noise in the classroom. The objective of this study is to identify the effect of background sounds on children's performance, sound evaluation and influence assessment based on a lab study conducted in the SenseLab. 335 school children (9 to 13 years old)from the previous studied schools participated in the lab study. They were subjected to a series of listening tests and evaluations in two acoustic test chambers (acoustically treated or untreated)with one of seven randomly played background sounds: 45 dB(A)or 60 dB(A)traffic noise, 45 dB(A)or 60 dB(A)children talking, 45 dB(A)or 60 dB(A)music, or no sound (≈30 dB(A)). A two-way ANOVA was applied to analyse the interaction effect of sound type and sound pressure level (SPL)on children's performance, sound evaluation and influence assessment in each of the chambers. Statistically significant interactions between the impact of sound type and SPL on children's phonological processing performance and their influence assessments were found in the untreated chamber.

@en

Indoor environmental quality (IEQ) in classrooms can have an effect on school children’s comfort, health, and performance. In most classrooms, the teacher is the only one who can take actions to change the IEQ. The objective of this study was to identify what teachers usually do to improve IEQ in classrooms and how these actions relate to children’s comfort perceptions. A survey was carried out among 1145 school children (9–12 years) in 21 primary schools (54 classrooms) in the Netherlands. Every child filled out a questionnaire about their comfort perception and every teacher filled out a questionnaire about their IEQ-improving actions and school children’s requests to change the IEQ. The relations among children’s comfort perceptions, their requests, and teachers’ actions were analysed through t-tests and chi-squared tests. The most common action conducted by teachers was opening windows because of the ‘too warm’ complaints. Correspondingly, the most frequent request of the children was opening/closing windows because of thermal discomfort. However, the teachers’ actions did not have a significant impact on children’s comfort perceptions, which means that teachers could not fulfil every child’s needs in a classroom, even though teachers’ actions did relate to the child’s requests.

@en

To study the combined effect of different environmental factors on children in a classroom setting, 250 children from seven primary schools were exposed to 36 different environmental configurations (‘all’ and ‘fewer’ acoustical panels; ‘displacement’ and ‘mixing’ ventilation; sound type: ‘children talk’, ‘traffic’, and ‘none’; and ‘direct’, ‘indirect’ and ‘soft’ lighting). In a four-way factorial design, they assessed with 18 groups on eight different days temperature, draught, noise, light and smell. Correlation, three-way ANOVA, comparison tests and multi-regression analysis were used to analyse relationships, and main, cross-modal and interaction effects. The results show that more acoustical panels had a positive effect on the children’s assessment of sound. Sound type had a main effect on the assessment of sound. Statistical significant cross-modal effects were found for lighting and sound type on the assessment of smell. Significant three-way interactions between ‘Vent’, ‘Sound’, and ‘Light’ types were found for smell and light in the ‘fewer panels’ situations; and for light in the ‘all panels’ situations. Multiple-regression analysis also showed that perception of smell was significantly related with draught, sound and light perception in ‘fewer panels’ conditions. Further studies on these cross-modal interactions are recommended, specifically at individual level.@en

To find out whether a surface finishing was preferred under different lighting conditions by school children, in the light test chamber of the SenseLab, 335 children from previous studied schools were asked to assess a desk surface during different light conditions. A two-way randomized design was used to test children's assessments for six school desks table tops (brown, yellow and grey wood, and, normal, matt and reflective white), under three different light conditions: energizing, calming, and focusing. A statistically relevant relationship was found for the three wooden surfaces, but none for the white ones. Such results may be due to the fact that better contrast between the participants' form and the surface appeared with the wooden-like surfaces, as opposed to that with the white surfaces. Similarly, white surfaces' characteristics seemed to be more difficult to assess (mattness, reflectiveness, opacity) as opposed to those fr the wooden-like surfaces (colour yellow, brown, grey).

@en

A previous field study showed that more than 85% of Dutch children reported they were bothered by noise in the classroom. To investigate the impact of acoustical treatment on children's phoneme identification, 335 school children (9 to 13 years old) from the previously studied schools were invited to take part in a series of tests in the acoustical chamber of the SenseLab. All the children performed two series of listening tests and evaluations in chamber A (untreated) and chamber B (acoustically treated) respectively, while at the same time one of seven background sounds (45dB or 60dB traffic noise, 45dB or 60dB children talking, 45dB or 60dB music, or no sound) were randomly played in the chambers. T-tests were conducted to compare the results of children's phonological process tasks, sound perceptions, and influence assessments in these two chambers. Results showed a statistically significant difference in children's sound perceptions (p=0.01). Children reported the untreated chamber A to be noisier.

@en

Background
While the indoor environmental quality of classrooms is a potential issue because it may affect the wellbeing of school children, the relations are still poorly studied. This study aimed to investigate the relations between classroom characteristics and health and comfort of school children.

Material and methods
A questionnaire was distributed among 1311 school children (8–12 years old, average 10) of 54 classrooms at 21 schools in The Netherlands. Additionally, the survey included an inspection of the school and its installations and an inspection of the classrooms surveyed using checklists, and monitoring of some environmental parameters (temperature, relative humidity and CO2 concentration) in the classrooms.

Results
Among the children studied, 87% was bothered by noise, 63% by smells, 42% by sunlight when shining, 35% didn't like the temperature in the classroom (too cold or too warm) and 34% experienced temperature changes. Main diseases reported comprised of allergies (26%), rhinitis (17%), hay fever (16%) and eczema (16%). Health and comfort in non-traditional schools was better than in the traditional schools studied (A non-traditional school is a school in which the way of educating children is different from the traditional way of education, according to a different educational theory). Physical building characteristics of the classrooms studied in the traditional schools were associated with the Classroom Symptom Index (location of school building, heating system, solar devices hampering opening windows or ventilation) and the Classroom Comfort Index (ventilation type, window frame colour, floor material and vacuum cleaning frequency).

Conclusions
Measures to improve acoustical, air, and thermal conditions of children in classrooms are needed. More research is required on the use of different lighting systems and use of different colours in classrooms.@en

This paper aims to design an “individually controlled system” (ICS) for children in class-rooms based on their preferences and needs. It is well known that a higher satisfaction of in-door environmental quality (IEQ), including thermal, air, visual and acoustical quality, can be achieved by giving occupants control over their local environment. However, knowledge about individual control of IEQ in classrooms by children is still limited. Based on a field sur-vey conducted in in 21 primary schools (54 classrooms with children aging from 9 to 12) in The Netherlands and a lab study performed in the SenseLab (a semi-lab environment at the premises of the TU Delft) of circa 350 children of some of the schools studied, in which pref-erences and needs of pupils, as well as perception about control of their individual IEQ, were collected, the first prototype of an ICS to improve their local environmental quality will be designed.@en

Good indoor environmental quality (IEQ) in classrooms is an essential requirement to ensure children’s comfort and learning performance. However, although in most studies the current situation of the IEQ in classrooms has been investigated, few or no studies have been focused on the way to ameliorate it. Recently, some researchers managed to utilize local control to improve local environment quality, but most of these studies have been focused on offices instead of classrooms. Existing knowledge about how to apply local control of IEQ in the classroom is very limited. This paper presents a summary of knowledge in both fields of IEQ in classrooms and local control. In addition, some issues will be discussed and new problems will be proposed. All of these discussions will illuminate the direction for further research on how to use local control to improve the IEQ in classrooms to facilitate childrens’ health and performance.@en