In this article a generic fault detection and diagnosis (FDD) method for demand controlled ventilation (DCV) systems is presented. By automated fault detection both indoor air quality (IAQ) and energy performance are strongly increased. This method is derived from a reference architecture based on a network with 3 generic types of faults (component, control and model faults) and 4 generic types of symptoms (balance, energy performance, operational state and additional symptoms). This 4S3F architecture, originally set up for energy performance diagnosis of thermal energy plants is applied on the control of IAQ by variable air volume (VAV) systems. The proposed method, using diagnosis Bayesian networks (DBNs), overcomes problems encountered in current FDD methods for VAV systems, problems which inhibits in practice their wide application. Unambiguous fault diagnosis stays difficult, most methods are very system specific, and finally, methods are implemented at a very late stage, while an implementation during the design of the HVAC system and its control is needed. The IAQ 4S3F method, which solves these problems, is demonstrated for a common VAV system with demand controlled ventilation in an office with the use of a whole year hourly historic Building Management System (BMS) data and showed it applicability successfully. Next to this, the influence of prior and conditional probabilities on the diagnosis is studied. Link to the formal publication via its DOI https://doi.org/10.1016/j.buildenv.2019.106632
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This study explores if multiple alterations of the classrooms' indoor environmental conditions, which lead to environmental conditions meeting quality class A of Dutch guidelines, result in a positive effect on students' perceptions and performance. A field study, with a between-group experimental design, was conducted during the academic course in 2020–2021. First, the reverberation time (RT) was lowered in the intervention condition to 0.4 s (control condition 0.6 s). Next, the horizontal illuminance (HI) level was raised in the intervention condition to 750 lx (control condition 500 lx). Finally, the indoor air quality (IAQ) in both conditions was improved by increasing the ventilation rate, resulting in a reduction of carbon dioxide concentrations, as a proxy for IAQ, from ~1100 to <800 ppm. During seven campaigns, students' perceptions of indoor environmental quality, health, emotional status, cognitive performance, and quality of learning were measured at the end of each lecture using questionnaires. Furthermore, students' objective cognitive responses were measured with psychometric tests of neurobehavioural functions. Students' short-term academic performance was evaluated with a content-related test. From 201 students, 527 responses were collected. The results showed that the reduction of the RT positively influenced students' perceived cognitive performance. A reduced RT in combination with raised HI improved students' perceptions of the lighting environment, internal responses, and quality of learning. However, this experimental condition negatively influenced students' ability to solve problems, while students' content-related test scores were not influenced. This shows that although quality class A conditions for RT and HI improved students' perceptions, it did not influence their short-term academic performance. Furthermore, the benefits of reduced RT in combination with raised HI were not observed in improved IAQ conditions. Whether the sequential order of the experimental conditions is relevant in inducing these effects and/or whether improving two parameters is already beneficial, is unknown.
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Teachers and students need good learning environments to perform well. In this study it is pre-supposed that the spatial properties of classrooms can contribute to the quality of the educational process. Thermal, acoustic and visual conditions and indoor air quality (IAQ) may be extremely powerful in order to support the in-class tasks of teachers and students. But what are the optimal conditions? And do schools provide optimal indoor 2019 ISES ISIAQ Joint Annual Meeting – Abstracts | 362 environmental conditions? Research shows that adequate ventilation and thermal comfort in classrooms could improve academic performance of students. However, different studies also suggest that poor indoor environmental quality in classrooms are common and, in some cases, even unhealthy. This study investigates the relationship between indoor air quality (IAQ), perceived indoor air quality (PIAQ) and building-related symptomsof students in university classrooms via subjective assessment and objective measurement. This study was carried out in 59 classrooms of a university of applied sciences in the northern part of the Netherlands during heatingseason. Responses from 366 students were obtained through a questionnaire. Results shows that carbon dioxide concentrations (CO2) exceed minimum Dutch guidelines in 36% of the observed classrooms. Moreover, after a 40 minute class this raised to 45% of the observed classes. Poor IAQ can affect teachers and students level of attention, cause arousal and increase the prevalence of building-related symptoms. A significant correlation was found between CO2 concentrations and PIAQ and between PIAQ and the ability to concentrate, tiredness and dry skin. The research findings imply that increased CO2 concentrations will affect the PIAQ of students and may cause inability to concentrate, increased tiredness and dry skin. These building-related symptoms can cause distraction and affect the academic performance of students negatively. It is highly recommended to improve IAQ in classrooms by offering better indoor environmental conditions through reducing CO2 concentrations.
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Background and aim – In this study, it is pre-supposed that the indoor environmental conditions of classrooms can contribute to the quality of the educational process. Thermal, acoustic and visual conditions and indoor air quality (IAQ) may be extremely supportive in order to support the in-class tasks of teachers and students. This study explores the influence of these conditions on the perceived comfort and quality of learning of students in higher education. Methodology – In a case study design, the actual IEQ of 34 classrooms which are spread over four school buildings in North Netherlands and 276 related student perceptions were collected. The measurements consisted of in situ physical measurements. At the same moment the perceived indoor environmental quality (PIEQ) and the perceived quality of learning (PQL) of students were measured with a questionnaire. Results – Observed are high carbon dioxide concentrations and high background noise levels. A relation was observed between perceived acoustic and visual conditions, IAQ, and the PQL indicating that a poor IEQ affects the PQL. A linear regression analyses showed that in this study the perceived impact on the quality of learning was mainly caused by perceived acoustic comfort. Originality – With the applied innovative measuring instrument it is possible to measure both the actual IEQ as well as the PIEQ and PQL. This method can also be used to assess a reference and intervention condition. Practical or social implications – The applied measuring instrument provides school management with information about the effectiveness of improved IEQ and students’ satisfaction, which can be the basis for further improvement.
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This study examines the impact of moderate and high lighting and indoor air quality (IAQ) conditions on students’ well-being during a regular academic course in higher education. To determine the precise contribution of these two indoor environmental factors, students’ perceptions of their well-being were examined with the Positive and Negative Affect, Basic Emotional Process, and Karolinska Sleepiness Scale. Data were collected from 83 students, resulting in 285 responses, distributed across four combinations of moderate and high IAQ conditions, resp. > 800 ppm ≤ 950 ppm carbon dioxide (CO2) and < 800 ppm CO2, and moderate and high horizontal illuminance (HI) levels, resp. 500 lx and 750 lx. The results indicated that high HI levels did not enhance students’ perceived well-being compared to moderate levels. However, high IAQ conditions significantly contributes to students’ well-being, compared to moderate conditions. Interaction effects between the two factors were observed at moderate conditions.
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The indoor air quality (IAQ) in classrooms in higher education can influence in-class activities positively. In this context, the actual IAQ and students' perceived IAQ (PIAQ), perceived cognitive performance (PCP), and short-term academic performance (SAP) were examined in two identical classrooms during regular academic courses. During the lecture, key performance indicators (KPI) for the IAQ, i.e. carbon dioxide concentration, particulate matter 2.5, and total volatile organic compounds, were measured. After the lecture, responses of 163 students were collected with a validated self-composed questionnaire and a cognitive test, which covered topics discussed during the lecture. A significant association between the IAQ KPI and the PIAQ was found (p < .000). The PIAQ significantly predicted the PCP (p < .05) and the PCP significantly predicted the SAP score (p < .01). These results indicate that the IAQ in classrooms is associated with the PIAQ and PCP, and therefore is associated with students' SAP.
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Backgroundand aim – In this study, it is pre-supposed that the indoor environmental conditions of classrooms can contribute to the quality of the educational process. Thermal, acoustic and visual conditions and indoor air quality (IAQ) may be extremely supportive in order to support the in-class tasks of teachers and students. This study explores the influence of these conditions on the perceived comfort and quality of learning of students in higher education.Methodology– In a case study design, the actual IEQ of 34 classrooms which are spread over four school buildings in North Netherlands and 276 related student perceptions were collected. The measurements consisted of in situ physical measurements. At the same moment the perceived indoor environmental quality(PIEQ) and the perceived quality of learning (PQL) of students were measured with a questionnaire.Results – Observedare high carbon dioxide concentrations and high background noise levels. Arelation was observed between perceived acoustic and visual conditions, IAQ,and the PQL indicating that a poor IEQ affects the PQL. A linear regressionanalyses showed that in this study the perceived impact on the quality oflearning was mainly caused by perceived acoustic comfort.Originality– With the applied innovative measuring instrument it is possible to measure both the actual IEQ as well as the PIEQ and PQL. This method can alsobe used to assess a reference and intervention condition.Practical or social implications – The applied measuring instrument provides schoolmanagement with information about the effectiveness of improved IEQ and students’ satisfaction, which can be the basis for further improvement.Type ofpaper – Research paper.
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This study explores if multiple alterations of the classrooms' indoor environmental conditions, which lead to environmental conditions meeting quality class A of Dutch guidelines, result in a positive effect on students' perceptions and performance. A field study, with a between-group experimental design, was conducted during the academic course in 2020–2021. First, the reverberation time (RT) was lowered in the intervention condition to 0.4 s (control condition 0.6 s). Next, the horizontal illuminance (HI) level was raised in the intervention condition to 750 lx (control condition 500 lx). Finally, the indoor air quality (IAQ) in both conditions was improved by increasing the ventilation rate, resulting in a reduction of carbon dioxide concentrations, as a proxy for IAQ, from ~1100 to
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Teachers and students need good learning environments to perform well. In this study, it is pre-supposed that the spatial properties of classrooms are important facilitators of the educational process. Ideally, school buildings in general and classrooms in particular should influence the educational process positively by providing a healthy and comfortable built environment. A healthy and comfortable indoor environment is provided by optimal conditions for IAQ, thermal comfort, acoustic comfort and visual comfort. A pleasant temperature, fresh air, good soundscape and lighting conditions will support the in-class tasks of lecturers and students. But do schools provide optimal environmental learning conditions? Maintaining adequate ventilation and thermal comfort in classrooms could significantly improve academic achievement of students. A first orientating literature study reveals that that classroom conditions are far from optimal and in some cases even unhealthy and affect the performance of teachers and students negatively. Overall, evidence suggests that poor indoor environment quality in schools is common and adversely influences the performance and attendance of students, primarily through health effects from indoor pollutants. Based on this evidence, it is highly recommended to improve environmental conditions in classrooms in higher education in The Netherlands by offering a better indoor air quality and thermal conditions and by improving the acoustic and lighting conditions.
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Purpose: This study aims to qualitatively examine the relationship between the indoor environmental quality (IEQ), lecturers’ and students’ perceived internal responses and academic performance. Design/methodology/approach: To capture user experiences with the IEQ in classrooms, semi-structured interviews with 11 lecturers and three focus group discussions with 24 students were conducted, transcribed, coded and analyzed using direct content analysis. Findings: The findings show that lecturers and students experience poor thermal, lighting, acoustic and indoor air quality (IAQ) conditions that may influence their ability to teach and learn. Maintaining acceptable thermal and IAQ conditions was difficult for lecturers, as opening windows or doors caused noise disturbances. In uncomfortable conditions, lecturers may decide to give a break earlier or shorten a lecture. When students experienced discomfort, it may affect their ability to concentrate, their emotional status and their quality of learning. Research limitations/implications: The findings originate from a relatively small sample, which might have limited the number and variety of identified associations between environment and users. Practical implications: Maintaining acceptable air and thermal conditions will mitigate the need to open windows and doors. Keeping doors and windows closed will prevent noise disturbances and related distractions. This will support the quality of learning in classrooms. This study reveals the end users’ perspectives and preferences, which can inspire designers of new school buildings in higher education. Originality/value: This study emphasizes the importance of creating and maintaining optimal IEQ conditions to support the quality of teaching and learning. These conditions are particularly relevant when classroom occupancy rates are high or outdoor conditions are unfavourable
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