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Occupant response to transitions across indoor thermal environments in two different workspaces

To understand how transition across different thermal zones in a building impacts the thermal perception of occupants, the current work examines occupant feedback in two work environments — nursing staff in hospital wards and the workers in an office. Both studies used a mix of subjective surveys and objective measurements. A total of 96 responses were collected from the hospital wards while 142 were collected from the office. The thermal environment in the hospital wards was perceived as slightly warm on the ASHRAE thermal sensation scale (mean TSV = 1.2), while the office workers rated their environment on the cool side (mean TSV =  0.15). The results also show that when the transitions were across temperature differences within 2 °C, the thermal perception was not impacted by the magnitude of the temperature difference — as reflected in occupant thermal sensation and thermal comfort/thermal acceptability vote. This would imply that the effect of temperature steps on thermal perception, if any, within these boundaries, was extremely short lived. These findings go towards establishing the feasibility of heterogeneous indoor thermal environments and thermal zoning of workspaces for human comfort.

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12/31/2017
Occupant response to transitions across indoor thermal environments in two different workspaces
product

Occupant response to transitions across indoor thermal environments in two different workspaces

To understand how transition across different thermal zones in a building impacts the thermal perception of occupants, the current work examines occupant feedback in two work environments — nursing staff in hospital wards and the workers in an office. Both studies used a mix of subjective surveys and objective measurements. A total of 96 responses were collected from the hospital wards while 142 were collected from the office. The thermal environment in the hospital wards was perceived as slightly warm on the ASHRAE thermal sensation scale (mean TSV = 1.2), while the office workers rated their environment on the cool side (mean TSV =  0.15). The results also show that when the transitions were across temperature differences within 2 °C, the thermal perception was not impacted by the magnitude of the temperature difference — as reflected in occupant thermal sensation and thermal comfort/thermal acceptability vote. This would imply that the effect of temperature steps on thermal perception, if any, within these boundaries, was extremely short lived. These findings go towards establishing the feasibility of heterogeneous indoor thermal environments and thermal zoning of workspaces for human comfort.

PDF

12/31/2017
Occupant response to transitions across indoor thermal environments in two different workspaces
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Thermal comfort in operating theatres for different types of ventilation systems

Thermal comfort in operating theatres is a less addressed research component of the in-door environment in operating theatres. The air quality naturally gets most attention when considering the risk of surgical site infections. However, the importance of thermal comfort must not be underestimated. In this research, the current thermal comfort situation of staff members is investigated. Results show that the thermal comfort for the members of a surgical team is perceived as not optimal. Application of the PMV and DR models needs further attention when applied for operating theatres. For the investigated ventilation systems, the differences in thermal comfort outcomes are small.

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12/31/2018
Thermal comfort in operating theatres for different types of ventilation systems

People 1

person

Gerard Schepers

Professor

Gerard  Schepers

Projects 6

project

Eggxpert

Eggshell particles as bio-ceramic in sustainable bioplastic engineering – ESP-BIOPACK Plastics make our lives easier in many ways. However, if they are not properly disposed of, they end up in the environment. Recently, biodegradable biopolymers, such as polylactic acid (PLA) and polyhydroxy alkanoates (PHAs), have moved towards alternatives for applications such as sustainable packaging. The major limitations of these biopolymers are the high cost, which is due to the high cost of the starting materials and the small volumes, and the poor thermal and mechanical properties such as limited processability and low impact resistance. Attempts to modify PHAs have been researched in many ways, such as blending various biodegradable polymers or mixing inorganic mineral fillers. Eggshell (10 million tons per year by 2030) is a natural bio-ceramic mineral with a unique chemical composition of calcium carbonate (>95% calcite). So far it has been regarded as a zero-value waste product, but it could be a great opportunity as raw material to reduce the cost of biopolymers and to improve properties, including the decomposition process at the end-of-life. In this project, we aim to develop eggshell particles that serve as bio-fillers in biopolymers to lower the cost of the product, to improve mechanical properties and to facilitate the validation of end-of-life routes, therefore, economically enhance the wide applications of such. The developed bioplastic packaging materials will be applied in SME partner EGGXPERT’s cosmetics line but also in other packaging applications, such as e.g. biodegradable coffee capsules. To be able to realize the proposed idea, the partnership between Chemelot Innovation and Learning Labs (CHILL), EGGXPERT B.V. and the Research Centre Material Sciences of Zuyd University of Applied Sciences is needed to research the physical, mechanical and end-of-life influences of eggshell particles (ESP) in biopolymers such as PLA and PHA and optimize their performance.

Ongoing
project

Ph.D.-project 'Examining in-class activities to facilitate academic achievement in higher education: a framework for optimal indoor environmental conditions'

Examining in-class activities to facilitate academic achievement in higher educationThere is an increasing interest in how to create an effective and comfortable indoor environment for lecturers and students in higher education. To achieve evidence-based improvements in the indoor environmental quality (IEQ) of higher education learning environments, this research aimed to gain new knowledge for creating optimal indoor environmental conditions that best facilitate in-class activities, i.e. teaching and learning, and foster academic achievement. The academic performance of lecturers and students is subdivided into short-term academic performance, for example, during a lecture and long-term academic performance, during an academic course or year, for example. First, a systematic literature review was conducted to reveal the effect of indoor environmental quality in classrooms in higher education on the quality of teaching, the quality of learning, and students’ academic achievement. With the information gathered on the applied methods during the literature review, a systematic approach was developed and validated to capture the effect of the IEQ on the main outcomes. This approach enables research that aims to examine the effect of all four IEQ parameters, indoor air quality, thermal conditions, lighting conditions, and acoustic conditions on students’ perceptions, responses, and short-term academic performance in the context of higher education classrooms. Next, a field experiment was conducted, applying the validated systematic approach, to explore the effect of multiple indoor environmental parameters on students and their short-term academic performance in higher education. Finally, a qualitative case study gathered lecturers’ and students’ perceptions related to the IEQ. Furthermore, how these users interact with the environment to maintain an acceptable IEQ was studied.During the systematic literature review, multiple scientific databases were searched to identify relevant scientific evidence. After the screening process, 21 publications were included. The collected evidence showed that IEQ can contribute positively to students’ academic achievement. However, it can also affect the performance of students negatively, even if the IEQ meets current standards for classrooms’ IEQ conditions. Not one optimal IEQ was identified after studying the evidence. Indoor environmental conditions in which students perform at their best differ and are task depended, indicating that classrooms should facilitate multiple indoor environmental conditions. Furthermore, the evidence provides practical information for improving the design of experimental studies, helps researchers in identifying relevant parameters, and lists methods to examine the influence of the IEQ on users.The measurement methods deduced from the included studies of the literature review, were used for the development of a systematic approach measuring classroom IEQ and students’ perceived IEQ, internal responses, and short-term academic performance. This approach allowed studying the effect of multiple IEQ parameters simultaneously and was tested in a pilot study during a regular academic course. The perceptions, internal responses, and short-term academic performance of participating students were measured. The results show associations between natural variations of the IEQ and students’ perceptions. These perceptions were associated with their physiological and cognitive responses. Furthermore, students’ perceived cognitive responses were associated with their short-term academic performance. These observed associations confirm the construct validity of the composed systematic approach. This systematic approach was then applied in a field experiment, to explore the effect of multiple indoor environmental parameters on students and their short-term academic performance in higher education. A field study, with a between-groups experimental design, was conducted during a regular academic course in 2020-2021 to analyze the effect of different acoustic, lighting, and indoor air quality (IAQ) conditions. First, the reverberation time was manipulated to 0.4 s in the intervention condition (control condition 0.6 s). Second, the horizontal illuminance level was raised from 500 to 750 lx in the intervention condition (control condition 500 lx). These conditions correspond with quality class A (intervention condition) and B (control condition), specified in Dutch IEQ guidelines for school buildings (2015). Third, the IAQ, which was ~1100 ppm carbon dioxide (CO2), as a proxy for IAQ, was improved to CO2 concentrations under 800 ppm, meeting quality class A in both conditions. Students’ perceptions were measured during seven campaigns with a questionnaire; their actual cognitive and short-term academic performances were evaluated with validated tests and an academic test, composed by the lecturer, as a subject-matter-expert on the taught topic, covered subjects discussed during the lecture. From 201 students 527 responses were collected and analyzed. 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 unknownFinally, a qualitative case study explored lecturers’ and students’ perceptions of the IEQ of classrooms, which are suitable to give tutorials with a maximum capacity of about 30 students. Furthermore, how lecturers and students interact with this indoor environment to maintain an acceptable IEQ was examined. Eleven lecturers of the Hanze University of Applied Sciences (UAS), located in the northern part of the Netherlands, and twenty-four of its students participated in three focus group discussions. The findings show that lecturers and students experience poor thermal, lighting, acoustic, and IAQ conditions which may influence teaching and learning performance. Furthermore, 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 pause earlier or shorten a lecture. When students experienced discomfort, it may affect their ability to concentrate, their emotional status, and their quality of learning. Acceptable air and thermal conditions in classrooms will mitigate the need to open windows and doors. This allows lecturers to keep doors and windows closed, combining better classroom conditions with neither noise disturbances nor related distractions. Designers and engineers should take these end users’ perceptions into account, often monitored by facility management (FM), during the renovation or construction of university buildings to achieve optimal IEQ conditions in higher education classrooms.The results of these four studies indicate that there is not a one-size fits all indoor environmental quality to facilitate optimal in-class activities. Classrooms’ thermal environment should be effectively controlled with the option of a local (manual) intervention. Classrooms’ lighting conditions should also be adjustable, both in light color and light intensity. This enables lecturers to adjust the indoor environment to facilitate in-class activities optimally. Lecturers must be informed by the building operator, for example, professionals of the Facility Department, how to change classrooms’ IEQ settings. And this may differ per classroom because each building, in which the classroom is located, is operated differently apart from the classroom location in the building, exposure to the environment, and its use. The knowledge that has come available from this study, shows that optimal indoor environmental conditions can positively influence lecturers’ and students’ comfort, health, emotional balance, and performance. These outcomes have the capacity to contribute to an improved school climate and thus academic achievement.

Finished
project

Rots in de Brand

Brandweermensen lopen het meeste gevaar als ze onder tijdsdruk een gebouw moeten verkennen, of een brand moeten blussen terwijl de situatie nog niet goed kan worden overzien. Omvallende muren, instortende plafonds of gewoon gestruikeld over door de rook onzichtbare brokstukken leiden tot vermijdbare letsels of zelfs slachtoffers. Met name de inzet bij branden in stedelijke parkeergarages onder woontorens vormen een enorm risico. Het inzetten van onbemande, op afstand bestuurbare voertuigen voor verkenning en bluswerk is een oplossing die binnen de brandweer breed wordt gedragen. De brandweer moet deze innovatieve technologie echter zien te omarmen. Zij werken nu vanuit hun intuïtie en weten direct hoe te acteren op basis van wat zij waarnemen. Praktijkgericht onderzoek heeft echter uitgewezen dat scepsis over de inzet van blusplatforms bij incidenten plaats heeft gemaakt voor zeker vertrouwen. Een blusplatform, voorzien van juiste sensoren kan de Officier van Dienst (OVD) ondersteunen bij het nemen van een beslissing om al dan niet tot een ‘aanval’ over te gaan. Praktijktesten hebben echter laten zien dat de huidige blusplatforms nog niet optimaal functioneren om als volwaardig ‘teamlid’ te kunnen worden ingezet. Dit heeft enerzijds met technologische ontwikkelingen (sensoren en communicatieverbindingen) te maken, maar anderzijds moet de informatievoorziening (human-machine interfacing) naar de brandweer beter worden afgestemd. In dit project gaan Saxion, het instituut fysieke veiligheid, de universiteit Twente, het bedrijfsleven en vijf veiligheidsregio’s onderzoeken hoe en wanneer innovatieve blusplatforms op een intuïtieve manier kunnen worden ingezet door training én (kleine) productaanpassing zodat deze een volwaardig onderdeel kunnen zijn van het brandweerkorps. Een blusplatform kan letselschade en slachtoffers voorkomen, mits goed ingezet en vertrouwd door de mensen die daarvan afhankelijk zijn. Het vak van brandweer, als beroeps of vrijwilliger, is een van de gevaarlijkste die er is. Laten we er samen voor zorgen dat het iets veiliger kan worden.

Finished