Search

This study proposes a novel 10-point numerical scale to evaluate long-term thermal comfort satisfaction. The available scale that verbally evaluates the short-term thermal comfort is thermal sensation vote (TSV) and this has substituted for the long-term thermal comfort assessment. However, the TSV has been questioned by many studies due to the ambiguous, widely different interpretation of each score and unequal perceived gaps between the scores. The paper argues the biological similarities between pain and temperature perceptions and proposes a numerical thermal comfort scale like that of long-term pain perception. Participants in a survey rated their long-term summer thermal comfort in the natural ventilation mode through the numerical and TSV scales. Ratings were compared after converting to degree hours based on monitoring temperature data for the same summer. The results show that the numerical scale provides an opportunity for respondents to express their long-term thermal comfort satisfaction level. Scoring by the numerical scale was convenient and clear to the respondents. The verbal scores of TSV, had different interpretations for individuals as each point was attributed to more than two values of degree hours. The score 'Neutral' was significantly ambiguous for assessing thermal comfort. [ABSTRACT FROM AUTHOR]

The central problem addressed by this paper is the fuel poverty experienced in Chile as a result of poor thermal performance of dwellings, a problem commonly encountered throughout the country, even in new housing. The domestic consumption of fuels used for thermal regulation of dwellings accounts for a large proportion of national energy use, gas emissions, and household expenditures. This study aims to alleviate these issues by presenting building designs that can provide comfortable indoor thermal conditions without a need for conventional energy fuels. Following the findings of field studies, the design of standard dwellings has been optimized using computational studies that were conducted with consideration for the country's main climatic regions. The results of this study have shown that the application of passive design measures can be sufficient for achieving thermal comfort conditions, thereby reducing the use of domestic fuels to near-zero levels in most of the country. [ABSTRACT FROM AUTHOR]

This paper evaluates the use of advanced natural ventilation (ANV) strategies in a range of climatic conditions from four cities in the UK. A prototype ANV system was proposed to determine the most effective case in mitigating overheating. The case was then assessed under identical simulation conditions for all four ANV strategies. The overheating criteria used in the research include the single temperature criterion from CIBSE Guide A and the adaptive thermal comfort overheating criteria from BS EN 15251. Both the current and future 'Design Summer Year (DSY)' weather data were used to examine the thermal performances of the proposed design. The findings show that shading, night cooling and heavy weight structures (ceiling) were all useful in mitigating overheating, with night cooling being identified as the most effective measure. The work assessed the use of ANV in both current and future scenarios to quantify the limits of outdoor environmental conditions under which natural ventilation is an effective strategy for achieving thermal comfort. The adaptive thermal comfort overheating criteria were proved to be easier to meet compared with the CIBSE single temperature criterion. With the adaptive overheating criteria, the given design is predicted to not overheat until 2050 in London Heathrow; and for other places evaluated in the UK (Edinburgh, Manchester & Birmingham), the design passes these criteria. The Centre-in ANV strategies proved to be more effective than the Edge-in strategies for space cooling due to the extended structure thermal mass. [ABSTRACT FROM AUTHOR]

Shared office spaces represent a challenge regarding thermal comfort. They have a diversity of occupants and expectations, and they require social interaction, which could imply restriction in adaptive actions, contrary to individual areas that usually allow total control. Hence, this paper aims to identify differences in thermal comfort criteria among individual and shared offices spaces by comparing adaptive opportunities and actions performed as well as thermal perception. Fieldwork was carried out in Chile in 18 office buildings, 9 in Concepcion (36°S), and 9 in Santiago (33°S). Thermal comfort surveys with simultaneous measurements of indoor environmental conditions were performed in each of these buildings during a single day in winter, spring and summer. The findings show variations in the criteria studied, which indicate that thermal requirements differ by spatial layout. Moreover, the results suggest that occupants of shared spaces have a wider comfort range; therefore, some kind of 'adaptation by coexistence' might be happening. [ABSTRACT FROM AUTHOR]

India is a vast country spread across five climatic zones. The current Indian building codes specify thermal comfort standards for naturally ventilated offices only. This paper presents a year-long field study carried out during 2015–16 to investigate thermal comfort in naturally ventilated (NV) classrooms of three government residential schools located in the composite climatic zone of India. A total of 1890 data sets were collected from children and teenagers in the age group of 10–18 years. The students in naturally ventilated classrooms were found to be more adaptive than what is prescribed in the ASHRAE thermal comfort standards. Indoor operative temperatures of 28.2°C and 19.4°C were recorded as the neutral temperatures of the summer and winter seasons, respectively. The study proposes a thermal comfort range of 16°C to 33.7°C for 80% acceptability. The study also proposes an adaptive thermal comfort model for naturally ventilated secondary school classrooms in composite climatic zones. The results show that students are adapted to higher temperatures in classroom environments. The study provides a baseline for further research in developing thermal comfort standards for secondary school classrooms in India. [ABSTRACT FROM AUTHOR]

European Standard EN 15251 has broken new ground. Firstly, it assembles existing information about optimizing thermal, air quality, acoustic and visual comfort so that designers can make energy calculations which embody all the best information about aspects of the environment that impinge on energy use. Secondly, it follows other standards in recognizing the different expectations occupants have of the thermal environment in mechanically and naturally ventilated buildings. Potentially this makes EN 15251 an important standard in the design and the evaluation of new and existing buildings. Therefore, it is essential to be clear about its strengths and weaknesses and to indicate ways in which future updates might improve on it. This paper considers the way in which the Standard is written, its underlying philosophy and purpose, and the ways in which it defines unacceptable thermal conditions and how they might be misunderstood. Questions are raised regarding the use of outdoor temperature to define indoor comfort as the basis for providing a comfortable indoor thermal environment. Suggestions are made for improving the Standard. La norme europeenne EN 15251 marque de nouvelles avancees. En premier lieu, elle rassemble les informations existantes relatives a l'optimisation du confort thermique, acoustique, visuel et lie a la qualite de l'air, de facon a permettre aux concepteurs d'effectuer des calculs energetiques qui soient l'expression du meilleur des informations relatives aux aspects environnementaux qui affectent l'utilisation de l'energie. En deuxieme lieu, cette norme suit les autres normes en ce qu'elle reconnait les differentes attentes qui sont celles des occupants en matiere d'environnement thermique dans des immeubles a ventilation mecanique et naturelle. Cela fait potentiellement de la norme EN 15251 une norme importante pour la conception et l'evaluation des immeubles neufs et existants. Il est par consequent essentiel d'en montrer clairement les points forts et les points faibles et d'indiquer les moyens par lesquels de futures mises a jour pourraient y apporter des ameliorations. Le present article examine la maniere dont la norme est redigee, la philosophie et le dessein qui la sous-tendent, ainsi que les facons dont elle definit les conditions thermiques qui ne sont pas acceptables et en quoi celles-ci pourraient etre mal comprises. Des interrogations sont soulevees concernant le fait de se baser, pour assurer un environnement thermique interieur confortable, sur l'utilisation de la temperature exterieure servant a definir le confort interieur. Des suggestions sont faites pour l'amelioration de cette norme. Mots cles: confort thermique adaptatif normes de construction immeubles utilisation de l'energie norme europeenne EN 15251 normes [ABSTRACT FROM AUTHOR]

In a changing climate there is increasing concern about the risk of overheating in UK buildings, particularly those with a low-carbon footprint which cannot rely on mechanical cooling. This gives rise to concern among building professionals about how overheating risk can best be assessed. Current Chartered Institution of Building Services Engineers (CIBSE) guidance uses a simple definition of overheating as the exceedance of 28°C for more than 1% of occupied hours, based on simulations using weather files from a 'design summer year' (DSY). There is increasing evidence that this criterion is both insensitive and open to abuse. This paper uses field surveys of thermal (dis)comfort and the adaptive thinking behind the British and European Standard BS EN15251 to propose a new approach. It takes account of the effect of indoor and outdoor climate on the dissatisfaction of building occupants. An alternative definition of overheating in buildings is proposed, along with an approach to predicting the magnitude and/or frequency of occurrence of overheating in buildings. Dans un climat en evolution, il existe une preoccupation croissante a l'egard du risque de surchauffe dans les immeubles du Royaume-Uni, en particulier ceux qui ont une empreinte carbone faible et ne peuvent pas compter sur un refroidissement mecanique. Cela amene les professionnels du batiment a se preoccuper de la maniere dont le risque de surchauffe peut etre le mieux evalue. Les informations actuellement fournies a titre indicatif par le CIBSE (Chartered Institution of Building Services Engineers) utilisent une definition simple de la surchauffe comme etant des temperatures depassant 28°C pendant plus de 1% des heures d'occupation, sur la base de simulations utilisant les fichiers meteorologiques de l'indice DSY (« Design Summer Year ») correspondant a une annee a ete chaud moyenne. Il est de plus en plus manifeste que ce critere n'a pas la sensibilite necessaire et incite aux abus. Cet article utilise des enquetes de terrain portant sur le confort ou l'inconfort thermique et les idees d'adaptation qui sous-tendent la norme britannique et europeenne BS EN15251 afin de proposer une approche nouvelle. Il prend en compte l'effet du climat interieur et exterieur sur l'inconfort des occupants de l'immeuble. Une autre definition de la surchauffe dans les immeubles est proposee, ainsi qu'une approche permettant de prevoir l'ampleur et/ou la frequence de l'apparition de cette surchauffe dans les immeubles. Mots cles: confort thermique adaptatif, confort, annee a ete chaud (DSY), inconfort, surchauffe, normes [ABSTRACT FROM AUTHOR]

Providing thermal comfort in schools has a significant impact on students' performance and health. Climate change may result in an increased risk of overheating. A clear understanding and definition of overheating in schools is needed. Overheating can occur for various reasons. In order to deal with the problem realistically, it is necessary to have the correct design benchmarks. The UK government has recently published new overheating guidelines for schools. A comparison is made between the existing and new overheating guidelines. This is based on an analysis of recorded temperature data from 140 classrooms in 18 naturally ventilated primary schools in London, UK, which is then compared with records of occupants' thermal comfort responses to indoor temperature. It was found that the old guidelines were too lenient, thereby allowing some overheating to occur. The new guideline is more stringent, but needs further development to reflect occupants' perceptions more accurately. Le fait d'assurer le confort thermique dans les écoles a un impact significatif sur les performances et la santé des élèves. Le changement climatique peut entraîner un risque accru de surchauffe. Il est nécessaire d'avoir une compréhension et une définition claires des excès de chaleur dans les écoles. Les surchauffes peuvent se produire pour différentes raisons. Afin de pouvoir traiter ce problème de manière réaliste, il est nécessaire de disposer des référentiels de conception corrects. Le gouvernement britannique a publié récemment de nouvelles directives contre les excès de chaleur destinées aux écoles. Il est procédé à une comparaison entre les directives existantes et nouvelles contre les excès de chaleur. Celle-ci est basée sur une analyse des données de température enregistrées dans 140 salles de classe de 18 écoles primaires à ventilation naturelle de Londres, au Royaume-Uni, qui a ensuite été comparée aux dossiers des réactions à la température intérieure éprouvées par les occupants en termes de confort thermique. Il a été constaté que les anciennes directives étaient trop laxistes, permettant ainsi que se produisent des surchauffes. La nouvelle directive est plus rigoureuse, mais a besoin d'être améliorée de manière à refléter avec plus de précision les perceptions des occupants. Mots clés:confort thermique adaptatif, référentiels, surchauffe, directive contre les excès de chaleur, salles de classe, référentiel thermique [ABSTRACT FROM AUTHOR]