Browsing by Subject "Thermal comfort"

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Open Access
Analysing the effects of thermal comfort and indoor air quality in design studios and classrooms on student performance
(IOP, 2019) Ranjbar, Ali
This study aimed to explore the various effects of different ventilation modes on the thermal comfort and indoor air quality in design education environment. It also investigated the relationship between the ventilation mode and student performance. Thus, an experimental study was conducted in both studio and classroom environments, in Interior Architecture and Environmental Design Department at Bilkent University, Ankara, Turkey. CO2 concentration values, indoor air temperature and humidity values as the main parameters of thermal comfort and indoor air quality was measured in both winter and summer seasons under the three modes of ventilation: 1) without opening door and windows mode setting; (2) natural ventilation mode and (3) the HVAC ventilation mode achieved by the TROX school-air unit. Under these three different modes for both attention and concentration levels, 100 students from the winter season, 50 students from summer season for the classroom environment, and 20 students from the winter season, 16 students from summer season for the studio environment participated. Results were calculated in IBM SPSS 21 software separately for both seasons and three different ventilation modes. As a result, the experimental and performance results have shown that the HVAC unit mode achieved the most satisfactory indoor environment in both seasons and higher levels of student performance.
Open Access
Analyzing the effects of thermal comfort and indoor air quality in design studios and classrooms on student performance
(2017-07) Ranjbar, Ali
The present study aims to evaluate the effects of the different ventilation modes on thermal comfort and indoor air quality in design studios and classrooms. It also investigates its associations with student performance. For this purpose, experimental and subjective measurements are used in both studio and classroom, in Interior Architecture and Environmental Design Department at Bilkent University, Ankara. CO2 concentration, indoor temperature and humidity values are collected in both winter and summer season under the three modes of ventilation: 1) without opening door and windows mode setting; (2) natural ventilation mode and (3) the mechanical TROX school-air unit mode. The thermal comfort and IAQ was investigated through CO2 concentration and temperature and humidity in these three different ventilation modes. Under these three modes in both seasons, student performance is assessed based on concentration and attention test results. Both experimental and subjective results have shown that the mechanical TROX school-air unit mode is the most satisfactory indoor environment in terms of standards, where the highest grade of students’ concentration and attention are obtained.
Open Access
The application of the physiologically equivalent temperature to determine impacts of locally defined extreme heat events within vulnerable dwellings during the 2020 summer in Ankara
(Elsevier, 2022-03-09) Santos Nouri, A.; Charalampopoulos, I.; Matzarakis, A.
This study addresses the limited work related to Heat Stress (HS) vulnerability within indoor/outdoor contexts and its relationship with local Extreme Heat Events (EHEs). Centred upon Ankara, the study focuses on building upon its weaker approach to human thermophysiological vulnerabilities in an era of climate change, and unregulated urban densification. Through newly defined local EHEs, the physiologically equivalent temperature (PET) (and its cumulative derivatives), were utilised to develop the limited approaches that utilise Energy Based Models in the scope of EHE risk management. The study was undertaken by processing hourly data from 2008 to 2020 from Ankara's Meteorological Station, and Esenboga Meteorological Station. At a finer 10 min resolution, an interior Kestrel Heat-stress Station was used to assess summer thermal conditions in 2020 within a thermally vulnerable, yet still very frequent, residential Turkish construction typology. Among other outcomes, the results indicated the permanency of indoor PET that remained above 27 °C during non EHE periods. In the case of a Very Hot Day (VHD33), PET remained between 29 and 32.9 °C for almost 24 h. The thermal index also indicated how forced convective cooling led to indoor reductions of PET by 3–4 K, and in duration of such HS levels to less than 2 h. © 2022
Open Access
Approaching environmental human thermophysiological thresholds for the case of Ankara, Turkey
(Springer, 2020-10-27) Santos Nouri, Andre; Afacan, Yasemin; Çalışkan, O.; Tzu-Ping, L.; Matzarakis, A.
The disclosed study undertook a ‘human centred-approach’ that ascertained and categorised environmental human thermophysiological risk factors by relating them to the human biometeorological system through the use of three widely utilised energy balance model (EBM) indices, the physiologically equivalent temperature (PET), the modified PET, and the universal thermal climate index (UTCI). The disclosed assessment was carried out over the past decade (i.e., 2010–2019) with a 3-h temporal resolution for the case of Ankara through two WMO meteorological stations to compare both local urban and peri-urban environmental conditions. The study recognised extreme annual variability of human physiological stress (PS) during the different seasons as a result of the biometeorological processing of the singular variables, which in the case of average PET for both stations, varied by up to 75 °C between the winter and summer for the same annual dataset (2012). In addition, all EBMs indicated higher heat stress within the city centre that were conducive of both urban extreme heatwaves and very hot days during the summer months, with extreme heat stress levels lasting for longer than a week with PET values reaching a maximum of 48 °C. Similar cold extremes were found for the winter months, with PET values reaching − 30 °C, and average PS levels varying lower in the case of the peri-urban station.
Open Access
Comparative analysis of wall materials for their operational energy performance in urban mid-rise residential buildings: a simulation-based study in Istanbul
(2024-05) Erincik, Gülce
As urbanization continues to drive a substantial share of global energy consumption and carbon emissions, mitigating the environmental footprint of residential buildings in urban areas becomes imperative. Although there are numerous studies focused on designing low embodied-carbon construction materials to mitigate the carbon footprint of the construction industry, there is a significant gap regarding the applications and operational performance of these alternative materials in urban environments, which results in low demand for them in the current construction market. This study focuses on evaluating the operational performance of low embodied-carbon alternative materials when they are used in mid-rise residential building envelopes in urban environments, with a particular emphasis on the energy consumption of buildings for achieving occupant thermal comfort. The study commences with a literature review of low embodied-carbon materials suitable as an infill material for exterior walls, followed by simulation-based assessments using Rhino-Grasshopper and OpenStudio software to compare the operational energy performance of the alternative materials against the conventional materials in Istanbul, Turkey. The results present the operational performance of the materials considering the local factors such as urban morphology and urban weather of the case study site in Istanbul. They also highlight possible improvements needed for some alternative materials to achieve or exceed the operational performance of conventional envelope materials. Hence, this research provides insights for architects, policymakers, and construction industry professionals by identifying materials with significant sustainability potential for urban environments and emphasizing the need for context-specific adaptations of them. It addresses a critical gap in the literature on the operational phase of low-embodied carbon construction materials and developing low-carbon residential architecture in urban environments.
Open Access
Defining local extreme heat thresholds and Indoor Cooling Degree Necessity for vulnerable residential dwellings during the 2020 summer in Ankara – Part I: Air temperature
(Elsevier Ltd, 2021-10-29) Andre Santos, Nouri; Çalışkan, Onur; Charalampopoulos, Ioannis; Cheval, Sorin; Matzarakis, A.
This study discusses the preliminary assessment of Indoor Cooling Degree Necessity (ICDN) based upon the standard air temperature (Ta) value of 22 °C which is defined to be the standard upper mean temperature limit (Tl) for interior comfort as defined by the WHO. By considering indoor air temperature (TaI), levelled oscillations above Tl are utilised to determine indoor temperature extremes/frequencies at a 10 min temporal resolution during the months of July and August 2020 in Ankara. These recordings were undertaken through the use of an interior in-situ Meteorological Station (MS), simultaneously, an outdoor in-situ MS was also mounted outside the naturally ventilated dwelling with the identical measurement interval period. Moreover, to supplement the encompassing outdoor data collection, two WMO MSs were utilised in the study to account for both encompassing local peri-urban Esenboga (EMS) and Ankara's urban (AMS) outdoor air temperatures (TaO) at a 1 h temporal resolution. In addition to the ICDN's identified variation of Tl levels, which frequently remained between +7 °C and +10 °C during periods of accentuated urban outdoor heat stress; their direct/latent cause-and-effect relationship with newly defined local extreme heat thresholds were established. Relative to July and August 2020, a total of 19 Very Hot Days (VHD33), 10 Monthly Tropical Night (MRT20), and 4 Heatwave Events (HWE31) were determined. These thresholds further underlined the growing need to associate indoor and outdoor heat stress during local extreme heat events, particularly in more vulnerable residential contexts; and moreover, in an era of increasing heat stress as result of rapid urbanisation and climate change. © 2021 The Authors
Open Access
In Press, Corrected Proof: Defining local extreme heat thresholds and Indoor Cooling Degree Necessity for vulnerable residential dwellings during the 2020 summer in Ankara – Part I: Air temperature
(Elsevier, 2021-10-29) Nouri, Andre Santos; Çalışkan, O.; Charalampopoulos, I.; Cheval, S.; Matzarakis, A.
This study discusses the preliminary assessment of Indoor Cooling Degree Necessity (ICDN) based upon the standard air temperature (Ta) value of 22 °C which is defined to be the standard upper mean temperature limit (Tl) for interior comfort as defined by the WHO. By considering indoor air temperature (TaI), levelled oscillations above Tl are utilised to determine indoor temperature extremes/frequencies at a 10 min temporal resolution during the months of July and August 2020 in Ankara. These recordings were undertaken through the use of an interior in-situ Meteorological Station (MS), simultaneously, an outdoor in-situ MS was also mounted outside the naturally ventilated dwelling with the identical measurement interval period. Moreover, to supplement the encompassing outdoor data collection, two WMO MSs were utilised in the study to account for both encompassing local peri-urban Esenboga (EMS) and Ankara’s urban (AMS) outdoor air temperatures (TaO) at a 1 h temporal resolution. In addition to the ICDN’s identified variation of Tl levels, which frequently remained between +7 °C and +10 °C during periods of accentuated urban outdoor heat stress; their direct/latent cause-and-effect relationship with newly defined local extreme heat thresholds were established. Relative to July and August 2020, a total of 19 Very Hot Days (VHD33), 10 Monthly Tropical Night (MRT20), and 4 Heatwave Events (HWE31) were determined. These thresholds further underlined the growing need to associate indoor and outdoor heat stress during local extreme heat events, particularly in more vulnerable residential contexts; and moreover, in an era of increasing heat stress as result of rapid urbanisation and climate change.
Open Access
Investigating the relationship of outdoor heat stress upon indoor thermal comfort and qualitative self-sleep evaluation: the case of Ankara
(2022-06) Ahan, Merve Münevver
Recently, the necessity of exploring the relationship between sleep quality and the thermal environment has amplified regarding increasing heat stress risk on the human body due to climate change, particularly in vulnerable-uninsulated buildings of Ankara. Within this scope, this study investigated occupants’ sleep quality and thermal comfort in insulated and uninsulated buildings under three local extreme heat event thresholds: (1) typical summer day (TSD25), (2) very hot day (VHD33), and lastly, (3) heat wave event (HWE31). Within a two-tiered approach to thermal comfort evaluations, the physiological thermal comfort of occupants was identified through the calculation of Physiologically Equivalent Temperature (PET) from the climatic data of local meteorological stations. On the other hand, the psychological thermal comfort and sleep quality of participants were evaluated by questionnaires during each heat event. The results of this study demonstrated that PETOut reached 43.5 °C, which indicates the extreme heat stress within PS grades during the VHD33s. The PET values were consistently higher in uninsulated buildings than in insulated buildings. Also, most of the mean psychological thermal comfort votes (TCVs) and sleep quality votes (SQVs) were better in uninsulated buildings than in insulated ones during TSD25 and HWE31s, while it was the opposite within extreme conditions of VHD33s. The outputs of this study contribute to interdisciplinary efforts to attenuate the existing and impending risks of climate change on human life by defining the influence of increasing outdoor heat stress on indoor spaces, thermal comfort, and the sleep quality of occupants.
Open Access
Investigating the relationship of outdoor heat stress upon indoor thermal comfort and qualitative sleep evaluation: The case of Ankara
(MDPI, 2023-09-06) Ahan, Merve Münevver; Nouri, Andre Santos; Matzarakis, A.
The necessity of exploring the relationship between sleep quality and the thermal environment has amplified regarding increasing heat stress risk on the human body due to climate change, particularly in vulnerable uninsulated buildings in Ankara. Within this scope, this study investigated occupants’ sleep quality and human thermal comfort in insulated and uninsulated buildings under three local extreme heat event thresholds: (1) typical summer days (TSD25), (2) very hot days (VHD33), and lastly, (3) heat wave events (HWE31). Within a two-tiered approach to thermal comfort evaluations, the human thermal comfort of occupants was identified through the calculation of physiologically equivalent temperature (PET) from the climatic data of local meteorological stations. The psychological thermal comfort and sleep quality of participants were evaluated by questionnaires during each heat event. The results of this study demonstrated that the physiological thermal load of the participants was highest during VHD33s, given that both outdoor and indoor PET values presented their highest values within VHD33 events. Furthermore, the outdoor PET values reached extreme heat stress based on physiological stress grades with 43.5 °C, which indicated the exacerbated vulnerability of Ankara during extreme heat events. The PET values were consistently higher in uninsulated buildings than in insulated buildings. Also, most of the mean psychological thermal comfort votes and sleep quality votes were better in uninsulated buildings than in insulated ones during TSD25s and HWE31s, while it was the opposite within extreme conditions of VHD33s. The outputs of this study contribute to interdisciplinary efforts to attenuate the existing and impending risks of climate change on human life by defining the influence of increasing outdoor heat stress on indoor spaces, thermal comfort, and the sleep quality of occupants.
Open Access
The maturing interdisciplinary relationship between human biometeorological aspects and local adaptation processes: an encompassing overview
(MDPI AG, 2019) Nouri, Andre Santos
To date, top-down approaches have played a fundamental role in expanding the comprehension of both existing, and future, climatological patterns. In liaison, the focus attributed to climatic mitigation has shifted towards the identification of how climatic adaptation can specifically prepare for an era prone to further climatological aggravations. Within this review study, the progress and growing opportunities for the interdisciplinary integration of human biometeorological aspects within existing and future local adaptation efforts are assessed. This encompassing assessment of the existing literature likewise scrutinises existing scientific hurdles in approaching existing/future human thermal wellbeing in local urban contexts. The respective hurdles are subsequently framed into new research opportunities concerning human biometeorology and its increasing interdisciplinary significance in multifaceted urban thermal adaptation processes. It is here where the assembly and solidification of ‘scientific bridges’ are acknowledged within the multifaceted ambition to ensuring a responsive, safe and thermally comfortable urban environment. Amongst other aspects, this review study deliberates upon numerous scientific interferences that must be strengthened, inclusively between the: (i) climatic assessments of both top-down and bottom-up approaches to local human thermal wellbeing; (ii) rooted associations between qualitative and quantitative aspects of thermal comfort in both outdoor and indoor environments; and (iii) efficiency and easy-to-understand communication with non-climatic experts that play an equally fundamental role in consolidating effective adaptation responses in an era of climate change.