Richard de Dear

Richard de Dear
The University of Sydney · School of Architecture, Design and Planning

PhD

About

376
Publications
242,264
Reads
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28,370
Citations
Additional affiliations
January 2012 - September 2017
The University of Sydney
Position
  • Managing Director
January 2015 - July 2015
Tsinghua University
Position
  • Professor
January 2010 - present
Macquarie University
Position
  • Professor (Associate)

Publications

Publications (376)
Article
Full-text available
It has recently become clear that using adaptive thermal comfort models to determine setpoint temperatures is a successful energy-saving method. Global models like ASHRAE 55 and EN16798-1 have been used in recent experiments using adaptive setpoint temperatures. This work, however, has taken a different route by concentrating on a region-specific A...
Article
Full-text available
Heating and cooling in buildings accounts for over 20% of total energy consumption in China. Therefore, it is essential to understand the thermal requirements of building occupants when establishing building energy codes that would save energy while maintaining occupants’ thermal comfort. This paper introduces the Chinese thermal comfort dataset, e...
Article
Our aim was to compare the ambient temperature thresholds for warm thermal discomfort, thermal unacceptability, and preference for cooler environment between post-and pre-menopausal women at different metabolic rates. A total of 38 women (15 pre-menopausal (46 ± 5 years); 23 post-menopausal (55 ± 3 years)), completed up to 3 experimental trials at...
Article
Virtual Reality technology has gained increased attention due to its capacity to provide immersive and interactive experiences to its users. Although increasing evidence has suggested that incorporating multisensory components in VR can promote the sense of presence and improve user performance, most of the current VR applications are limited to vi...
Article
Full-text available
A better understanding of the psycho-physiological mechanisms driving human thermal perception during dynamic conditions is important to improve physiological-based thermal comfort models. During thermal transients, the two phenomena of thermal overshoot and thermal alliesthesia concurrently affect thermal comfort. However, they have to date been a...
Article
Buildings not only provide shelter to the occupants but also security, safety and comfort, as well as signifying economic and socio-cultural status. The high energy intensity of buildings has become a matter of concern worldwide in the context of climate change and global warming. Adaptive comfort principles and guidelines afford greater design opp...
Preprint
Full-text available
Within the soundscapes of open-plan offices, irrelevant speech has consistently been reported as the most distracting, and causing performance decrements for workers. Notwithstanding this generalization, the 'babble' created by multiple simultaneously active talkers can sometimes provide beneficial sound masking, but due to spatial release from mas...
Preprint
Full-text available
Open-plan offices (OPOs) have been around for more than half a century now, chronicling the vicissitudes of workplace topography amongst other factors. This paper addresses one such factor - the sound environment in occupied OPOs in relation to several objective workplace parameters, using measurements in contemporary OPOs and comparisons with stud...
Article
Indoor Positioning Systems (IPS) appear to offer great potential to study the movement and interaction of people and their working environment, including office workplaces. But little is known about appropriate durations for data collection. In this study, location observations collected from 24 office workers on a 1220 m² office floor over a 3-mon...
Article
Studies that attempt to model real patterns of residential occupant behaviour have become increasingly popular over the last decade. Most research of this kind tend to produce behaviour profiles based on an average occupant, yet the prediction of residential energy consumption varies significantly according to behavioural profiles of individual hou...
Article
Full-text available
The emerging “smart grid” paradigm with associated demand-management programs, such as demand-response (DR), calls for enhanced building energy flexibility. This can be achieved by time-shifting or -shaving building heating and cooling peak loads through the implementation of heating and cooling set-point temperature modulations. However, designing...
Article
Full-text available
Urban overheating, driven by global climate change and urban development, is a major contemporary challenge that substantially impacts urban livability and sustainability. Overheating represents a multifaceted threat to the well‐being, performance, and health of individuals as well as the energy efficiency and economy of cities, and it is influence...
Article
While it is evident that thermal environment plays a significant role in human sleep quality, currently there remains a paucity of literature on the assessment of sleeping thermal environment. In this study, the two-node model has been adapted to evaluate sleeping thermal environments through two phases of work - modifications to the model's inputs...
Article
Superimposition of global warming on urban heat islands is making outdoor cooling infrastructure critical to the maintenance of walkability of many cities. How to better arrange thermal respite (cooling infrastructure) to maximise pedestrians’ thermal comfort is still unclear. In this study, the thermal discomfort accumulating during episodic exerc...
Article
Full-text available
The experience of nature can bring various psychological benefits, including attention restoration, stress recovery, and mood improvement. Application of biophilic design principles to incorporate various forms of natural elements in workplaces can improve their occupants’ productivity and psychological well-being. However, most of the research reg...
Article
Full-text available
Several research studies have ranked indoor pollution among the top environmental risks to public health in recent years. Good indoor air quality is an essential component of a healthy indoor environment and significantly affects human health and well-being. Poor air quality in such environments may cause respiratory disease for millions of pupils...
Article
This study investigates the hypothesis that thermal adaptive opportunities available to building occupants affect their cognitive performance and mental workload. The change rate of cerebral blood flow (Δtotal Hb) was measured by Near Infra-Red Spectroscopy (NIRS) and interpreted as the metric of mental workload in subjects while performing cogniti...
Article
The seven-point thermal sensation scale provides a consistent measurement protocol widely applied in both field studies and lab experiments. Whilst thermal comfort studies have been carried out in diverse languages and cultures across the globe, there are suspicions among the research community whether the scale carries the same meaning when transl...
Article
Full-text available
Indian residences are vulnerable to heat-driven discomfort amid the mounting prevalence of weather extremes, residential design and construction practices, and densifying urbanscapes. Therefore, it is vital to understand the thermal comfort characteristics of nationwide residences. This study proposes an adaptive thermal comfort model based on year...
Article
Full-text available
Background Increasing air conditioner use for cooling indoor spaces has the potential to be a primary driver of global greenhouse gas emissions. Moving indoor air with residential fans can raise the temperature threshold at which air conditioning needs to be turned on to maintain the thermal comfort of building occupants. We investigate whether fan...
Article
There have been much research focus on modelling various types of occupant thermal adaptive behaviour with an aim to improve the reliability of building energy performance simulation (BEPS) tools. However, most existing studies exploring occupant interaction with residential building systems limit their scope to a single, isolated behaviour (e.g. w...
Article
Office workers spend much of their working day sitting or standing still, which can have dramatic impacts on their health. The physical environment has long been regarded as influencing people's behaviour, including how much and how often they move. Developing a deeper understanding of relationships between specific spatial and environmental attrib...
Article
Full-text available
Growth in energy use for indoor cooling tripled between 1990 and 2016 to outpace any other end use in buildings. Part of this energy demand is wasted on excessive cooling of offices, a practice known as overcooling. Overcooling has been attributed to poorly designed or managed air-conditioning systems with thermostats that are often set below recom...
Article
Assessment criteria for thermal comfort in residential buildings are often defined on the basis of the adaptive comfort model due to their typical operational characteristics – i.e. mixed-mode or naturally ventilation. However, recent field studies demonstrate that the current adaptive comfort model prescribed in the international standard does not...
Article
Green infrastructure has the potential to cool urban environments and reduce the health burden due to heatwaves. This study develops a new method to quantify the benefits of urban heat mitigation technologies on human heat balance and population mortality. The Heat Health Impact (HHI) method is based on the state-of-the-art, multi-parameter model,...
Conference Paper
Full-text available
Noise disturbance in open-plan offices (OPOs) has been a systemic issue throughout their history. This paper presents preliminary results from a study where an occupant survey (N = 366) was conducted in 30 office spaces within 9 buildings, along with measurements using the ISO 3382-3 method, and measurements of the sound environment during occupanc...
Article
A key to the development of more effective interventions to promote movement and reduce physical inactivity in office workplaces may be to measure and locate individual's spatial movement. Using an activity space estimation method, high resolution location data collected from 15 office workers over 12 days were used to estimate and analyse the loca...
Article
An experimental study on the influence of climatic thermal exposure on human thermal preference was carried out. Fifty-one Chinese female migrants were recruited in Australia and divided into two groups according to their recent climatic exposures. Group A comprised subjects who had arrived in Sydney's summer from China's winter within two weeks pr...
Article
Full-text available
Occupants' thermal sensitivity influences comfort temperature, thermal comfort models, and building energy simulation. To date, a universal thermal sensitivity estimate (i.e. 0.5/°C), the so-called Griffiths Constant, has been widely used to estimate comfort temperatures. However, recent field evidence indicates that the constant is actually a vari...
Article
Ongoing urbanization has led to complexities in the urban terrain, increasing roughness length within the atmospheric surface layer, and introduced highly turbulent wind flow at pedestrian height. This research aims to explicitly examine the effect of wind flow turbulence on thermal perception under outdoor conditions. A wind tunnel with passive gr...
Article
Occupants’ interactions with building components determine the timing and magnitude of energy demand. Therefore a more realistic representation of energy-related occupant behaviours in energy simulations will enhance the accuracy of predicted building energy demand. The aim of this paper was to assess occupancy and behavioural patterns in Australia...
Article
This paper presents results of a longitudinal field study which aims to investigate adaptive comfort behaviours (i.e. turning on air-conditioner, turning on fans and opening windows or doors) in residential buildings. Field measurements were conducted in 43 homes in Tianjin, northern China, from Spring through early Winter in 2016. Occupants' ‘righ...
Article
Heat extremes (ie, heatwaves) already have a serious impact on human health, with ageing, poverty, and chronic illnesses as aggravating factors. As the global community seeks to contend with even hotter weather in the future as a consequence of global climate change, there is a pressing need to better understand the most effective prevention and re...
Article
Hot ambient conditions and associated heat stress can increase mortality and morbidity, as well as increase adverse pregnancy outcomes and negatively affect mental health. High heat stress can also reduce physical work capacity and motor-cognitive performances, with consequences for productivity, and increase the risk of occupational health problem...
Article
In a field study conducted in office settings in Sydney, Australia, background survey and right-here-right-now thermal comfort questionnaires were collected from a sample of office workers. Indoor environmental observations, including air temperature, mean radiant temperature, air velocity, and relative humidity, were also recorded and matched with...
Article
Full-text available
Buildings could actively participate in the emerging smart electrical grid if they were able to incorporate dynamic modulations of indoor temperature set-points. But the mechanisms of dynamic thermal perception remain relatively poorly understood and we are still far from being able to design and control temperature fluctuations that would be comfo...
Article
The assessment of local and short-term thermal discomfort in buildings has been widely investigated, and different metrics are available in the literature to predict the likelihood of dissatisfied people. These metrics are named right-here and right-now discomfort indexes and constitute the basis for evaluating long-term thermal comfort conditions...
Article
Despite a wide range of energy efficiency measures being implemented, carbon emissions from the building sector continues to rise. Against the backdrop of rapidly increasing cooling energy demand, mixed-mode (MM) ventilation approach has extensively been studied by the building science community as a way to lift comfort indoors whilst minimising en...
Article
An innovative bioclimatic metric based on the Universal Thermal Climate Index (UTCI) is developed to quantify human thermal physiological heat stress. The Heat Stress Exposure (HSE) metric includes both duration and intensity dimensions of heat exposure, and in this paper it is applied to the Sydney Australia climatology. Geographic Information Sys...
Article
Full-text available
Research into human thermal perception indoors has focused on “neutrality” under steady‐state conditions. Recent interest in thermal alliesthesia has highlighted the hedonic dimension of our thermal world that has been largely overlooked by science. Here, we show the activity of sensory neurons can predict thermal pleasure under dynamic exposures....
Article
Office workers can spend significant periods of time being stationary whilst at work, with potentially serious health consequences. The development of effective health interventions could be aided by a greater understanding of the location and environmental context in which this stationary behaviour occurs. Real time location systems (RTLS) potenti...
Article
Full-text available
Air conditioning (A/C) is generally responsible for a significant proportion of total building energy consumption. However, occupants’ air conditioning usage patterns are often unrealistically characterised in building energy performance simulation tools, which leads to a gap between simulated and actual energy use. The objective of this study was...
Article
Open-plan offices (OPOs) have been around for more than half a century now, chronicling the vicissitudes of workplace topography amongst other factors. This paper addresses one such factor – the sound environment in occupied OPOs in relation to several objective workplace parameters, using measurements in contemporary OPOs and comparisons with stud...
Article
Indoor Environmental Quality (IEQ) reflects a building's performance in relation to the health, comfort and wellbeing of its occupants. Conventional IEQ measurement strategies fail to capture spatial or temporal variations in IEQ. Recent technological developments in IEQ monitoring and occupant location tracking provide opportunities to monitor IEQ...
Article
Full-text available
Thermal comfort research has been historically centred around the concept of “thermal neutrality”. Thermal neutrality originates from the steady-state indoor environment and is increasingly questioned when used to define the optimum sensation in outdoor environments. This calls for new criteria, designated for non-steady state and dynamically evolv...
Article
The psychometric tool known as the thermal sensation scale has been extensively used in outdoor thermal comfort research. However, this one-dimensional descriptive scale was originally developed for indoor assessments and therefore has certain shortcomings in outdoor settings. The scale contains no affective information such as pleasure and it over...
Article
Thermal comfort standards have suggested a number of physical indices which can be calculated from either building simulations or in situ physical monitoring to assess the long-term thermal comfort of a space. However, the prohibitively high cost of sensor technologies has limited the applications of these physical indices, and their usefulness has...
Article
Sleep is essential for the body to recover from both the physical and psychological fatigue accruing throughout the day, and to restore energy to maintain bodily functions. Bedroom environmental quality is one of the key causes of sleep disturbance, so a better understanding of the associations of bedroom temperature and ventilation rate (using CO2...
Article
The impact of urban district morphology on the ventilation performance of a residential windcatcher was assessed in three different urban scenarios through a series of wind tunnel experiments. Geometry of the urban context and external obstacles affect the characteristics of wind flow reaching the individual buildings. The ventilation performance o...
Article
In order to achieve comfort, or to remove discomfort, building occupants constantly interact with the indoor environment through various adaptive behaviors. The purpose of this study is to better understand the adaptive thermal comfort mechanisms by investigating the interrelationship between the indoor thermal environments, the expectation of the...
Article
Full-text available
Thermal comfort research has been traditionally based on cross-sectional studies and spatial aggregation of individual surveys at building level. This research design is susceptible to compositional effects and may lead to error in identifying predictors to thermal comfort indices, in particular in relation to adaptive mechanisms. A relationship be...
Article
Ongoing urbanization and urban densification are leading to an increasing number of tall buildings, giving rise to an increasingly complex urban morphology which, in turn, is complicating the pedestrian-level wind environment of urban areas. As a key climatic element determining pedestrian outdoor thermal comfort, wind is represented in most of the...
Article
The rapid escalation of cooling demand in buildings set against the backdrop of a global climate emergency is intensifying research activity on adaptive thermal comfort. In this review of the topic spanning the last 21 years we examine progress or lack thereof, in various research themes. These include adaptive comfort theory, adaptive comfort prac...
Article
Full-text available
The recent release of the largest database of thermal comfort field studies (ASHRAE Global Thermal Comfort Database II) presents an opportunity to perform a quality assurance exercise on the first generation adaptive comfort standards (ASHRAE 55 and EN15251). The analytical procedure used to develop the ASHRAE 55 adaptive standard was replicated on...
Article
Full-text available
This study explores how climatic background or long-term thermal history influences individuals’ in-the-moment thermal comfort experiences. This investigation was conducted at eight mixed-mode university buildings in United Kingdom whose occupants had diverse thermal histories. The research design consisted of simultaneous environmental measurement...
Article
Comfort performance of a wind tower in a residential setting was evaluated in a series of wind tunnel experiments using a sealed, four storey apartment building model at 1:100 scale. This study was structured into three phases; first, the pressure distribution over the wind tower openings and the building fenestrations were measured in a boundary l...
Article
Griffiths method is a widely used to estimate the comfort temperature of occupants. Although 0.5/K has been widely used as the representative thermal sensitivity (Griffiths constant) on various building types, this value was derived mainly from office data relying on assumptions that have not been fully field-validated (i.e., the assumption of no a...
Article
Full-text available
Between 2017 and 2018, we conducted a longitudinal field experiment in a mixed-mode ventilation building located in Wollongong Australia, with a particular focus on occupant thermal comfort and adaptive behaviour. This study investigated how different building operation modes i.e. air-conditioning (AC) and natural ventilation (NV), can have an impa...
Article
Full-text available
In response to the change of indoor thermal environment, building occupants constantly interact with the surrounding environment through various adaptive behaviours. The purpose of this study is to better understand the adaptive thermal comfort mechanisms by investigating the interrelationship between the expectation of the occupants (the psycholog...
Article
The Griffiths method is widely used in thermal comfort studies to derive building users’ comfort temperature, or thermal neutrality as it is sometimes known. A single value (so called the Griffiths Constant, typically 0.5/°C) is prescribed as a representation of thermal sensitivity of building occupants to indoor temperature variations, which in tu...
Article
Mixed-mode (MM) ventilation approaches are becoming increasingly popular as a more energy efficient alternative to conventional HVAC solutions. By integrating both natural ventilation and mechanical cooling strategies, mixed-mode (or hybrid) building operation is able to achieve comfortable indoor environments whilst minimising reliance on energy i...
Article
This paper investigates variability in the key ISO 3382-3:2012 metrics, based primarily on the repeatability and reliability of these metrics, using repeated measurements in open-plan offices. Two types of repeated measurements were performed in offices – Type1 (n = 36), where the same path over workstations was measured from opposite ends, and Typ...
Article
Previous studies have demonstrated that non-thermal factors may affect occupants' thermal response in the indoor environment. The effects of demographic and contextual factors on thermal perception have been extensively studied, yet in previous studies, confounding variables have not been commonly controlled; it is also not known how these factors...
Article
We assessed whether increasing airflow with an electric fan is similarly effective as decreasing air temperature with air cooling (AC) in preventing heat-related reductions in productivity, and elevations in body temperatures and discomfort in a warm/humid indoor environment. In 48 experimental trials, we compared the reduction in the human heat st...
Article
Aging populations pose significant social challenges for many countries including China. The elderly spends most of their time inside built environments, so a better understanding of their thermal comfort indoors is important. This study investigated the perceptual and physiological responses of elderly subjects to different operative temperatures...