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Thermal comfort models can be used to gain insight into important building design variables and predict whether a given design will provide satisfactory thermal conditions. There is a need for better industry standards and awareness towards thermal comfort as a multi-domain construct is increasing. However, despite the research efforts of academics, research outcomes in the field of thermal comfort do not live up to their full potential because they are difficult to scale. In this review, scalability is presented as a construct which characterizes the ability of a thermal comfort model to aid in the understanding and prediction of thermal comfort conditions in real-world practice, and more specifically the design of office buildings. A literature search of recent scientific publications is conducted, resulting in 77 articles on multi-domain thermal comfort modelling. The scoping review identifies current scalability challenges associated with implementing existing thermal comfort models in practice and seeks to steer the research field towards generating more reliable models that contribute to the assessment of thermal comfort in office buildings, with particular focus on the design stage. We propose to do that by identifying potential avenues for future research that are related to several aspects of model scalability, namely, model scope, resolution, and portability.

A daycare center (DCC) is the most important indoor environment for young children besides their homes, where they keep the habit of daytime sleeping. They are vulnerable and susceptible to the health effects of airborne contaminants. Therefore, it is essential to keep a healthy indoor sleeping environment for young children in daycare centers. However, only a few studies have analyzed indoor air quality (IAQ) in bedrooms of DCCs. This study aims to learn more about the IAQ of bedrooms of DCCs through a field survey and analyzing CO2 concentration data. The field survey was conducted to collect detailed information on occupants and bedroom design with the ventilation system. It is found that around 60% of the bedrooms do not meet the requirement of airflow rate according to Dutch Building Code. Also, ventilation systems in bedrooms are not designed according to room geometry, number of occupants, and their ages. As for the analysis of CO2 concentration, it is found that 39% of the bedrooms have reported CO2 concentrations higher than 1000 ppm with a daily average time of 111 minutes. According to those findings, the status of the DCCs’ IAQ is not satisfying and needs further improvement.

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

There is a growing need for accurate low-cost indoor air quality (IAQ) sensors in schools. Therefore, a climate chamber performance study is conducted to evaluate the current scenario of low-cost sensors or monitors (LCMs) capable of measuring CO₂ and particulate matter (PM). Finally, the LCMs are compared using grading criteria to find out the best performing ones. Keywords: Low-cost monitors, sensors, indoor air quality, performance study, schools

Daycare centers (DCCs) are where infants and toddlers (0–4 years old) spend the most time besides their homes. Given their higher susceptibility to the effects of air pollutants, as compared to older children and adults, indoor air quality (IAQ) is regarded as an essential parameter to monitor in DCCs. Recent advances in IAQ monitoring technologies have enabled the deployment of low-cost air quality monitors (LCMs) and single sensors (LCSs) to continuously monitor various indoor environments, and their performance testing should also be performed in the intended indoor applications. To our knowledge, there is no study evaluating the application of LCMs/LCSs in DCCs scenarios yet.Therefore, this study is aimed to assess the response of five types of LCMs (previously not tested) and five LCSs to typical DCCs emission activities in detecting multiple IAQ parameters, i.e., particulate matter, carbon dioxide, total volatile organic compounds, temperature, and relative humidity. These LCMs/LCSs were compared to outcomes from research-grade instruments (RGIs). All the experiments were performed in a climate chamber, where three kinds of typical activities (background; arts-and-crafts; cleaning; [in a total of 32 events]) were simulated by recruited subjects at two typical indoor climatic conditions (cool and dry [20 ± 1 °C & 40 ± 10%], warm and humid [26 ± 1 °C & 70 ± 5%]).Results showed that tested LCMs had the ability to capture DCCs activities by simultaneously monitoring multiple IAQ parameters, and LCMs/LCSs revealed a strong correlation with RGIs in most events (R2 values from 0.7 to 1), but, for some events, the magnitude of responses varied widely. Sensirion SCD41, an emerging CO2 sensor built on the photoacoustic sensing principle, had a more accurate performance than all tested NDIR-based CO2 sensors/monitors. In general, the study implies that the selection of LCMs/LCSs for a specific application of interest should be based on emission characteristics and space conditions.

The extensive use of sensors is quickly becoming a standard feature of modern new buildings. Apart from the use of regular Building Management System (BMS) data, we see the addition of sensors that monitor in more detail the indoor environmental quality and the use and performance of innovative (and local) system solutions. This is also combined with integrated energy solutions at supra-building level. The assumption is that all these data are valuable to arrive at buildings that can optimize their operation towards indoor environmental and other sustainable performance indicators. In this research, data from a large modern building that combines office and educational rooms, features an innovative façade design and is connected to an aquifer thermal energy storage are considered. In order to perform detailed analyses, several sensor and data related issues had to be resolved first. In this paper we provide a procedure for structuring the data as was available for this specific building, originating from different sources. The outcomes provide a practical basis for other buildings to assess the correctness and quality of the sensor data and the analysis potential. An example of an analysis is presented. In addition, the paper demonstrates how the obtained measurement data can be used to calibrate a simulation model that is employed to analyse the ventilative cooling potential of the innovative façade in comparison to shading., CLIMA 2022 conference, 2022: CLIMA 2022 The 14th REHVA HVAC World Congress

Policy paper

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.

Exposure to increased concentrations of particulate matter (PM2.5) is related to a higher risk of respiratory and vascular diseases. Indoors, cooking appears to be a major source of PM2.5. In dwellings it has been demonstrated that cooking can lead to concentrations well above the health limits. However, only little is known about the concentrations typically observed in professional kitchens where cooking is the major activity. Therefore, an inventory field study has been set up to measure PM2.5 exposure in the breathing zone of chefs in professional restaurants. In total seven restaurants took part in the study. In all kitchens, PM2.5 exposure in the breathing zone of the chef and at two locations in the kitchen was measured. During the measurements activities of the chef were listed and characteristics of the kitchens were mapped (e.g. open/closed kitchen, type of ventilation, type of food that is prepared). The initial results show that in all restaurants, chefs are exposed to concentrations above the WHO-limit, i.e. average daily exposure of 25 µg/m³. Cooking style, hood and background concentration in the kitchen are factors contributing to the concentration in the kitchen. However, the peak exposure of the chef appears to be highly dependent on behavior and location in relation to the stove and exhaust hoods.

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.

Het is algemeen bekend dat het binnenmilieu in gebouwen zoals in woningen, scholen en kantoren de gezondheid en het welzijn van de gebruikers beïnvloedt. Een slecht binnenmilieu leidt tot discomfort, verminderde alertheid, vermindering van de prestaties van gebruikers en veroorzaakt zelfs absenties als gevolg van gezondheidsklachten en ziektes. Helaas komen klachten met betrekking tot het binnenmilieu vaak voor. De vraag is hoe het binnenmilieu in klaslokalen kan worden verbeterd. Dit is belangrijk omdat in een ideaal binnenmilieu zowel de student als de docent optimaal kan functioneren en presteren.

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 symptoms of 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 heating season. 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.

The indoor environmental quality (IEQ) of buildings affects health, productivity and wellbeing of its occupants. Simultaneously, energy consumption remains an issue of concern. IEQ in school buildings is critical, due to the high occupant density and influence of IEQ on student academic performance. In this research, the performance of an innovative system, combining ventilation and floor cooling/heating, is investigated through full-scale measurements in a mock-up and in a real classroom. Ventilation efficiency is assessed using the step-down tracer gas method. Thermal comfort focuses on local (non-uniform) thermal discomfort as this is most critical in a densely populated classroom. With increasing flow rates, the ventilation efficiency assessment shows a transition from displacement ventilation to mixing ventilation, and therefore reduced efficiency. Additionally, high flow rates can cause draught problems near supply grilles.

A local operating theatre ventilation device which ventilates the wound area only, was investigated applying a parameter study. The ventilation device is combined with a blanket which lies over the patient during the operation. Two configurations were studied: configuration 1 where HEPA-filtered air was supplied around and parallel to the wound area and configuration 2 where HEPA-filtered air was supplied from the top surface of the blanket, perpendicular to the wound area. The objective of the parameter study was to identify critical parameters. A simplified setup, which consisted of a sideways contaminated airflow and a HEPA-filtered airflow, was studied by experiments and CFD simulations. Particle concentrations (≥0.5µm) were measured at the wound, relative to a non-ventilated situation with only sideways contaminated airflow (N=30 per series; expressed in %). The effect of supply velocity, temperature and contaminant velocity were investigated. In isothermal conditions relative particle concentrations of 0-11% and 0-1% were measured for configuration 1 and 2 with a supply velocity of 0.40m/s and 0.30m/s respectively. However, differences between both configurations were not significant. Furthermore, configuration 1 was more sensitive to lower supply velocities (P

Surgical side infections occurred in 2.9% of the operations in conventionally ventilated operating theaters in The Netherlands. New performance-based Dutch guidelines offer the opportunity to apply alternative systems. Therefore, a local ventilation system was studied where only the wound area and the instrument tables are ventilated. The clean air supply around the wound area was combined with a blanket which lies over the patient during the operation. Two configurations were studied: HEPA-filtered air supply around and parallel to the wound area (configuration 1) and from the top surface of the blanket, perpendicular to the wound area (configuration 2). Similar approaches were applied to the instrument tables. The performance was tested in a detailed full-scale mock-up of an operating theatre. Relative particle concentrations were determined according to Dutch guidelines. In the centre of the wound area, relative particle concentrations varied between 1% and 10% for both configurations. The variances were probably caused due to irregular contamination in the periphery and imperfections of the prototypes. The results of the instrument tables were more uniform and resulted in relative particle concentrations of approximately 1% (configuration 1) and 0% (configuration 2) at the center of the tabletop. Although both configurations gave a reduced particle concentration in the wound area and on the instrument table compared to the contaminated periphery, only configuration 2 of the instrument table performed conform the VCCN guideline.

The design and realization of a healthy indoor environment is a challenge that is investigated from different perspectives at the unit Building Physics and Systems (BPS; Faculty of Architecture, Building and Planning) of Eindhoven University of Technology. Performance requirements (for instance, with respect to air quality, thermal comfort and lighting) and performance based assessment methods are the point-of-departure, focusing at computational techniques supporting the design process. Different specific application fields such as dwellings, offices, schools, but also, operating theatres, churches, musea and multifunctional stadiums, underline the applied approach that is part of the research within the unit. In the design of healthy environments, the performance based design assessment is crucial in arriving at innovative design solutions and optimized indoor and outdoor environments. In this assessment computational support tools and experimental verification play an important role. However, assessing the right indicators in an objective way, applying the correct tools and correct application of these tools is not yet well established. Alongside, developments are still ongoing. The work performed in the unit by the different researchers relates to the research questions that can be derived from this notice. The paper gives an introduction to the Unit BPS and presents a brief overview of recent and ongoing research. An extensive list of references is provided for further reading and supports the conclusion that healthy environments can and should be addressed from a wide angle.

This paper summarizes an experimental and numerical study into a ventilation concept that combines displacement ventilation with task conditioning, the so-called desk displacement ventilation (DDV) concept. The study uses steady-state and transient results to discuss the applicability of the DDV concept for standard office room configurations. The evaluation of the concept focuses on the micro/macroclimate and thermal comfort. Results show that the separation between micro- and macroclimate, a characteristic of task conditioning, is less pronounced. Furthermore, the thermal comfort conditions at the desk limit the cooling capacity of a DDV system. Finally, the transient characteristics of the concept do not conform to stated requirements for task conditioning systems. The main conclusion, therefore, is that there is no particular advantage in sitting close to a displacement ventilation unit. An improvement of the DDV system is proposed by incorporating a parallel system that provides the fresh air near head level. The improvement of the combined system has been investigated using computational fluid dynamics.

This paper introduces the desk displacement ventilation concept, which combines displacement ventilation with task conditioning. The experimental setup and results of full-scale steady-state and transient measurements and numerical simulations are described for a typical office configuration. Results are used to evaluate the concept with regard to the micro/macroclimate and thermal comfort. The steady-state results show that the separation between the micro- and macroclimate, which is characteristic of task conditioning, is less pronounced and may require improvement of the concept. This effect is investigated further via transient experiments. Results of the transient study show that the application of the displacement ventilation principle for task conditioning purposes is not suitable for standard office configurations. It should at least be supported by an additional system that introduces the air at higher velocity close to the occupant, of which several system types are already available today.

One of the important performance requirements for an air distribution system for an operating room (OR) is to provide good indoor environmental conditions in which to perform operations. Important conditions in this respect relate to the air quality and to the thermal conditions for the surgical team and the patient. Previous research has shown that some types of air distribution systems used in ORs may contribute to the reduction of surgical site infection (SSI). However, despite improved efficiency of air distribution systems, combined with new methods of infection control, technological developments in medical equipment and use of antibiotics, SSI is still a real risk and remains relatively high for certain types of surgery. One of the identified causes is inadequate performance of air distribution systems. Although various air distribution systems/strategies are available for application in ORs, no general assessment methodology is available to objectively compare different systems for a given design problem on the basis of identified performance indicators. This may result in the application of inadequately designed systems, affecting the health, safety and comfort of the patient and surgical team. The focus in this research, therefore, is on the design decision support information. The objective is to develop a methodology to support designers in the objective performance assessment of air distribution system designs for ORs, with a further focus on the application of computational simulation in this design assessment. To reach this goal, a number of measures were taken, briefly comprising of: extensive literature review; interviews with designers and hospital decision makers; observations in ORs; and a survey among experts in the field of heating, ventilation and air-conditioning (HVAC) and computational simulation. The Basis for the general research methodology applied in this work is the Design Research Methodology. The more specific methodology developed to assess air distribution systems combines the Performance Based approach with the Building Evaluation Domain Model. The latter method provides structure to the design problem by identifying different building levels and stakeholders. In this structure, the performance approach resulted in the definition of performance requirements and a listing of important performance indicators (mainly) related to the indoor air quality and thermal comfort in ORs. Computational simulation, such as building energy simulation, air flow network models and computational fluid dynamics, coupled or stand-alone, are introduced and recognized for their potential to assess the performance of air distribution systems in the design phase. Their application in practice, however, is still limited. Within the context of the developed methodology, use of computational simulation is indispensable. Some significant barriers to the current use of computational simulation have been identified. However, research is still in the process of addressing these areas. Besides a listing of performance indicators with respect to air distribution systems for ORs, an evaluation procedure for deciding on the appropriate evaluation method to predict the performance indicators is proposed. The evaluation procedure comprises five steps. First, selection of the zones of interest to be evaluated (e.g., workstation, instrument table and breathing zone); Second, identification of the boundary conditions to calculate the performance indicators; Third, identification of the airflow dynamic in the zone(s) of interest; Four, sensitivity analysis to verify the accuracy of the evaluation method chosen; Finally, identification of the robustness of the design solution by performing uncertainty and parameter sensitivity analysis. Based on this analysis, the designer will be able to verify if the air distribution system design performs properly and meets the client´s needs. The final stage of this research consisted of verifying if the proposed approach realizes the intended objectives, and if the method can be used in practice. A survey among researchers with expertise in building HVAC systems and computational simulation was used as a means for this evaluation. The results of this initial investigation indicated a positive reaction towards the general set-up of the procedure and towards its principal ideas to arrive at a design support methodology with respect to the evaluation of air distribution systems for operating rooms. However, the step between theory and practice still has a number of barriers. The complexity of the procedure, followed by resource constraints (time, knowledge and financial) were mentioned as barriers for its current complete application. The extent to which these barriers will prevent (or not) the use of the developed approach in practice should be explored. Options and directions for improvements are specified. The conclusions also indicate the need for further confirmation of the actual design improvement possible by applying the approach in a practical case.