Christhina Candido

Adaptive thermal comfort in Australian school classrooms

This survey of thermal comfort in classrooms aimed to define empirically the preferred temperatures, neutral temperatures and acceptable temperature ranges for Australian school children, and to compare them with findings from adult populations. The survey was conducted in a mixture of air-conditioned, evaporative-cooled and naturally ventilated classrooms in nine schools located in three distinct subtropical climate zones during the summer of 2013. A total of 2850 questionnaires were collected from both primary (grade) and secondary (high) schools. An indoor operative temperature of about 22.5°C was found to be the students’ neutral and preferred temperature, which is generally cooler than expected for adults under the same thermal environmental conditions. Despite the lower-than-expected neutrality, the school children demonstrated considerable adaptability to indoor temperature variations, with one thermal sensation unit equating to approximately 4°C operative temperature. Working on the industry-accepted assumption that an acceptable range of indoor operative temperatures corresponds to group mean thermal sensations of −0.85 through to +0.85, the present analysis indicates an acceptable summertime range for Australian students from 19.5 to 26.6°C. The analyses also revealed between-school differences in thermal sensitivity, with students in locations exposed to wider weather variations showing greater thermal adaptability than those in more equable weather districts.

BOSSA: a multidimensional post-occupancy evaluation tool

Research findings point to three methodological shortcomings of current post-occupancy evaluation (POE) tools: (1) contextualizing results, (2) adding instrumental data side by side to survey results and (3) producing meaningful feedback to its key stakeholders. This paper introduces the holistic BOSSA (Building Occupants Survey System Australia) and tools developed under this projects scope in close collaboration with industry. It aims to present and discuss the statistical analysis used in the BOSSA tool, distilling the survey results down to nine indoor environmental quality (IEQ) dimensions and their association with four overall indices. Principal component analysis (PCA) extracted nine IEQ dimensions that were uncorrelated with each other: spatial comfort, indoor air quality, personal control, noise distraction and privacy, connection to the outdoor environment, building image and maintenance, individual space, thermal comfort, and visual comfort. Four separate multiple regression analyses were conducted, one for each global evaluation item as an independent variable: work area comfort, building satisfaction, productivity and health. This statistical analysis provided the rational basis of BOSSAs scoring system, designed to simplify how occupant survey results are communicated to key stakeholders from the property industry and researchers.

Thermal pleasure in built environments: alliesthesia in different thermoregulatory zones

The principle of thermal alliesthesia indicates that the hedonic character of a thermal environment is determined as much by the general state of the subject as by the environment itself. An environmental stimulus that offsets or counters a thermoregulatory load error will be pleasantly perceived, and vice versa. Extant empirical evidence supporting thermal alliesthesia only exists for instances of core temperature deviation. Yet the reconciliation of alliesthesia with contemporary neurophysiological discourse (in the previous paper in this series) renders the concept directly relevant to everyday experiences in built environments where core temperature rarely deviates from neutral values. New experimental data are presented that explore alliesthesia in non-steady-state conditions across three different physiological states: thermoneutral; the upper and lower fringes of the thermoneutral zone; and mild excursions into the sweating and shivering regulatory zones. Thirteen human subjects evaluated the hedonic tone of a sequence of temperature step-changes and ramps. It was found that the psychophysiological principle of thermal alliesthesia operates within the thermoneutral zone, making it equally relevant to quotidian indoor environments as it is to the extremes found in traditional physiological research. Non-steady-state built environments can potentially offer spatial alliesthesia through carefully managed contrasts between local and mean skin temperature trends. Transitional zones are suggested as design solutions.

From thermal boredom to thermal pleasure: a brief literature review

The most recent review of the ASHRAE Standard 55 (2010) incorporates the dialectic between static and adaptive approaches to thermal comfort by proposing different recommendations for air-conditioned and naturally ventilated buildings. Particularly in naturally ventilated buildings, this standard aligns with three important topics in research field of thermal comfort during the last decades: (i) air movement enhancement versus draft, (ii) control availability and its impact on occupants’ satisfaction, and (iii) the search for thermal pleasure. This paper presents the rationale behind these three research topics and discusses its positive influence when moving from thermal comfort towards thermal pleasure.

Aplicabilidade dos limites da velocidade do ar para efeito de conforto térmico em climas quentes e úmidos

Este trabalho discute os limites dados para a velocidade do ar pelas normas ASHRAE 55 (2004) e ISO 7730 (2005). Para tal, realizou-se uma analise comparativa entre os valores-limite para a velocidade do ar definidos por essas normas e as respostas dos usuarios em relacao a preferencia e aceitabilidade do movimento do ar obtidas em experimentos de campo realizados em Maceio/AL. Resultados indicam que ambas as normas especificam valores para a velocidade do ar inferiores aos desejados pelos usuarios. Os resultados da preferencia do movimento do ar indicam que significativa percentagem dos usuarios demanda “maior movimento do ar”. Quando associada as respostas da aceitabilidade do movimento do ar, a insatisfacao dos usuarios ficou mais evidente, assim como a demanda por maior velocidade do ar. O mesmo movimento de ar, considerado como inaceitavel em climas frios e temperados, e desejado pelos usuarios em climas umidos. Nesse contexto, a aplicabilidade de limites maximos para a velocidade do ar provenientes de estudos com caracteristicas climaticas diferentes deve ser evitada. Tais limites devem vir de resultados de experimentos de campo em ambientes naturalmente ventilados, onde os usuarios possam utilizar de oportunidades adaptativas para reestabelecer o conforto termico. Futuras normas brasileiras devem focar em tais questoes, visando limites de velocidade que correspondam a expectativa dos usuarios em climas quentes e umidos.

Designing activity-based workspaces: satisfaction, productivity and physical activity

ABSTRACT Activity-based working (ABW) provides office workers with a variety of indoor workspaces purposively designed to accommodate different tasks. Despite an increased use of ABW, studies focusing on its impact and the resultant office design are yet to follow suit. This paper addresses this knowledge gap by providing empirical evidence from studies conducted before and after relocation from contemporary open-plan offices to ABW spaces. Results from post-occupancy evaluation (POE) surveys (n = 896 responses), spot measurements of indoor environmental quality (IEQ) and step-count monitoring (one case study; n = 20 participants) before and after relocation are reported. A total of 10 workspaces participated (six combi and four ABW) in this study. Design features were documented and analyzed. While there were limited differences in the measured IEQ conditions between office layouts investigated here, ABW workspaces yielded significantly higher satisfaction results on key IEQ dimensions, perceived productivity and health. Office layout was also found as a significant (or nearly significant) predictor of occupants’ lightly active and sedentary time but did not affect occupants’ daily step counts and distance they travelled. These results highlight the significance and impact of office layout and human-centred approach to design on occupants’ satisfaction, perceived productivity and incidental physical activity opportunities.

Indoor Spaces Environmental Evaluation for Office Buildings at CUASO—Applicability of the BOSSA Time Lapse

This study assesses the user perception of the Indoor Environmental Quality (IEQ) of workspaces by means of application of the BOSSA Time-Lapse System—developed by the University of Sydney and University of Technology, Sydney/Australia. It is a Building Occupancy Survey System Australian (BOSSA) tool, designed to assess the IEQ of workspaces by means of a questionnaire. Supporting the current Master Plan of the Armando Salles de Oliveira University Campus (CUASO), its buildings are being used as case studies for the development of BOSSA Brazil System. The first case study was conducted at the Laboratory of Environmental and Energy Studies (LABAUT), located at the Faculty of Architecture and Urbanism of the University of Sao Paulo (FAUUSP). This study was conducted into two different stages. Stage 1, named BOSSA Time-Lapse Base Case, was comprised of 12 volunteers participating in a critical analysis, helping to: (1) understand the functionality of the BOSSA Time-Lapse System; (2) identify translation issues and inconsistency in the questions and, (3) adapt the BOSSA System, which was developed in Australia, to the Brazilian reality. Stage 2, named Second Application of BOSSA Time-Lapse questionnaire, was comprised of four different volunteers invited to respond to the questionnaire without any influence from the researchers. Stage 2 helped to: (1) evaluate the user satisfaction/dissatisfaction with his/her workspace; and, (2) analyze his/her relations with the environment and the building architecture, using the BOSSA Time-Lapse questionnaire. Results show that the translation issues should be reviewed, and that the building has a high level of satisfaction among its users. The dissatisfaction results show high levels of noise, lack of privacy and natural light in some workstations, mostly related to workspace layout. The questionnaire applied at stage 2 identified different results when it comes to satisfaction and/or dissatisfaction with environmental comfort issues. This analysis will contribute to the understanding of the BOSSA Time-Lapse questionnaire, and its application in office buildings in Brazil, as well as to analyze variables of the building IEQ. It will also help to understand the use and application of the BOSSA System methodology internationally.