The Chinese thermal comfort dataset.

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, established by seven participating institutions under the leadership of Xi'an University of Architecture and Technology. The dataset comprises 41,977 sets of data collected from 49 cities across five climate zones in China over the past two decades. The raw data underwent careful quality control procedure, including systematic organization, to ensure its reliability. Each dataset contains environmental parameters, occupants' subjective responses, building information, and personal information. The dataset has been instrumental in the development of indoor thermal environment evaluation standards and energy codes in China. It can also have broader applications, such as contributing to the international thermal comfort dataset, modeling thermal comfort and adaptive behaviors, investigating regional differences in indoor thermal conditions, and examining occupants' thermal comfort responses.

An immersive multisensory virtual reality approach to the study of human-built environment interactions: Technical workflows.

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 visual and auditory senses. In this article, a novel method of integrating thermal-related devices (heat lamps and fans) into Virtual Reality was developed. Automated interaction with the thermal-related devices was achieved using Arduino-based control module with its program embedded into the VR platform-Unity. The functions, hardware and software requirements of the multisensory Virtual Reality system as well as the step-by-step procedures are detailed to provide a reproducible workflow for future applications.•A practical workflow to integrate thermal apparatus into Virtual Reality.•Dynamic airflow and radiative heating incorporated into Virtual Reality.•Automated process to allow user interaction with the thermal components in Virtual Reality.

How many days of indoor positioning system data are required to characterise typical movement behaviours of office workers?

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-month period, were analysed to determine how many days are required to estimate their typical movement and spatial behaviours. The analysis showed that up to 8 days of data was sufficient to characterise participants' typical daily movement behaviours and 10 days were required to estimate their typical spatial mobility. However, the results also indicate that 5 weeks of data collection are required to gather the necessary 10 days of data from each participant. These findings will help researchers and workplace professionals to understand the capabilities and requirements of IPS when considering their use in indoor work environments.

Effect of adaptive opportunity on cognitive performance in warm environments.

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 cognitive tasks (n-back tests) with, or without access to thermal adaptive opportunities such as regulable fan-induced air flow and clothing insulation adjustment. Participants underwent three experimental conditions: Condition 22 (operative temperature to = 22 °C without adaptive opportunities), Condition 28 (to = 28 °C without adaptive opportunities), and Condition 28w (to = 28 °C with adaptive opportunities. Under Condition 28w, thermal sensations were neutral, while thermal satisfaction and comfort levels were higher than those reported for Condition 28, and the same as those reported under Condition 22. The subjects' mean skin temperature under Condition 22 was the lowest at 32.1 °C, followed by Condition 28w at 33.6 °C, while the highest, 34.5 °C was recorded in Condition 28. No significant differences were observed in accuracy and reaction time of n-back tests between the three different environmental conditions. Under Condition 28w, mental fatigue levels and the left side Δ total Hb results were lowest out of all three conditions, although the differences failed to reach statistical significance. Availability of adaptive opportunities plays a role in expanding the range of thermal environmental conditions for optimal cognitive task performance in a moderately warm environment (to = 28 °C). This finding cannot be fully explained by the direct effect of adaptive behaviours on human heat balance and associated physiological responses, but the unexplained component may potentially be attributed to the psychological dimension of human adaptive response. These findings and their interpretation within an adaptive comfort framework are consistent with the extended-U hypothesis of cognitive performance.

A sex/age anomaly in thermal comfort observed in an office worker field study: A menopausal effect?

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 each questionnaire according to the time and location. During exploratory data analyses, we observed that female subjects aged over 40 and 50 or younger registered significantly warmer sensations than other subjects, male and female, from other age ranges. To further explore this phenomenon, the sample of building occupants was classified into two groups-women of perimenopausal age (over 40 and 50 or younger) while the remaining respondents served as a reference group for comparison. Women in the perimenopausal age range demonstrated an increased perception of warmth (p < 0.01) and expressed thermal dissatisfaction more frequently (p < 0.01) than the reference group respondents who were exposed to the same indoor environmental conditions. Furthermore, women of perimenopausal age also expressed preference for cooler thermal environments, that is, lower air temperature (p < 0.01) and greater air movement (p<0.01) than the reference group, and their thermal neutrality (ie, the room temperature corresponding to a neutral thermal sensation) was approximately 2°C cooler than that of the reference group (20.7°C vs 22.4°C). A potential physiological explanation for the distinct thermal perception of women aged over 40 and 50 or younger observed in this study could stem from menopausal symptoms-the presence of hot flushes and dysregulation of the thermoregulatory system.

Activity space, office space: Measuring the spatial movement of office workers.

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 location and extent of their daily spatial movement whilst in an office work-based setting. The results indicated that the method, kernel density estimation, combined with location data offers significant opportunities to not only measure and compare spatial movement behaviours but also simultaneously identify the locations where the behaviours occur. Combined with other data streams, this method will allow researchers to further investigate the influence of different environmental characteristics on these behaviours, potentially leading the development of more effective, longer lasting interventions to promote movement and reduce stationary behaviour, ultimately improving the health of office workers.

Overcooling of offices reveals gender inequity in thermal comfort.

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 recommended comfort temperatures. Prior research has reported lower thermal comfort for women in office buildings, but there is insufficient evidence to explain the reasons for this disparity. We use two large and independent datasets from US buildings to show that office temperatures are less comfortable for women largely due to overcooling. Survey responses show that uncomfortable temperatures are more likely to be cold than hot regardless of season. Crowdsourced data suggests that overcooling is a common problem in warm weather in offices across the US. The associated impacts of this pervasive overcooling on well-being and performance are borne predominantly by women. The problem is likely to increase in the future due to growing demand for cooling in increasingly extreme climates. There is a need to rethink the approach to air-conditioning office buildings in light of this gender inequity caused by overcooling.

Hot weather and heat extremes: health risks.

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 problems. Almost half of the global population and more than 1 billion workers are exposed to high heat episodes and about a third of all exposed workers have negative health effects. However, excess deaths and many heat-related health risks are preventable, with appropriate heat action plans involving behavioural strategies and biophysical solutions. Extreme heat events are becoming permanent features of summer seasons worldwide, causing many excess deaths. Heat-related morbidity and mortality are projected to increase further as climate change progresses, with greater risk associated with higher degrees of global warming. Particularly in tropical regions, increased warming might mean that physiological limits related to heat tolerance (survival) will be reached regularly and more often in coming decades. Climate change is interacting with other trends, such as population growth and ageing, urbanisation, and socioeconomic development, that can either exacerbate or ameliorate heat-related hazards. Urban temperatures are further enhanced by anthropogenic heat from vehicular transport and heat waste from buildings. Although there is some evidence of adaptation to increasing temperatures in high-income countries, projections of a hotter future suggest that without investment in research and risk management actions, heat-related morbidity and mortality are likely to increase.

Reducing the health effects of hot weather and heat extremes: from personal cooling strategies to green cities.

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 response measures that can be implemented, particularly in low-resource settings. In this Series paper, we describe how a future reliance on air conditioning is unsustainable and further marginalises the communities most vulnerable to the heat. We then show that a more holistic understanding of the thermal environment at the landscape and urban, building, and individual scales supports the identification of numerous sustainable opportunities to keep people cooler. We summarise the benefits (eg, effectiveness) and limitations of each identified cooling strategy, and recommend optimal interventions for settings such as aged care homes, slums, workplaces, mass gatherings, refugee camps, and playing sport. The integration of this information into well communicated heat action plans with robust surveillance and monitoring is essential for reducing the adverse health consequences of current and future extreme heat.

Predicting thermal pleasure experienced in dynamic environments from simulated cutaneous thermoreceptor activity.

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. A numerical model of cutaneous thermoreceptors was applied to skin temperature measurements from 12 human subjects. A random forest model trained on simulated thermoreceptor impulses could classify pleasure responses (F1 score of 67%) with low false positives/negatives (4%). Accuracy increased (83%) when excluding the few extreme (dis)pleasure responses. Validation on an independent dataset confirmed model reliability. This is the first empirical demonstration of the relationship between thermoreceptors and pleasure arising from thermal stimuli. Insights into the neurophysiology of thermal perception can enhance the experience of built environments through designs that promote sensory excitation instead of neutrality.

Dynamic thermal pleasure in outdoor environments - temporal alliesthesia.

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 evolving outdoor settings. To address this need, we investigated thermal pleasure dynamics in outdoor environments based on thermal alliesthesia - a psychophysiological framework for understanding the hedonic responses elicited by non-steady-state thermal exposures. Detailed field studies were conducted in Sydney, Australia, during a 30-day period covering both summer and winter with a total of 35 subjects. The thermal sensation scale was quantitatively divided into four alliesthesial potential areas - two with moderate and two with strong alliesthesial potential - based on their divergence to the preferred sensation. We find that the temporal pleasure change (dP) can be predicted using thermal sensation change (dT). The results showed that linear regression performed strongly (R2 = 0.77 for summer and R2 = 0.79 for winter) in predicting dP when subjects' preceding sensation was in the strong alliesthesial potential zones - namely the 'Hot' and 'Cold' areas. When subjects' prior thermal sensation fell in the thermoneutral zone with moderate alliesthesial potential, a quadratic fit against dT provides a more reasonable prediction of dP (R2 = 0.61 for summer and R2 = 0.56 for winter). The dynamic thermal pleasure models provide a more nuanced subjective interpretation of outdoor urban spaces that includes thermal pleasure and delight. This study contributes further empirical support to the thermal alliesthesia framework and extends its application scope into outdoor thermal comfort research.

Movement at work: A comparison of real time location system, accelerometer and observational data from an office work environment.

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) potentially offer the opportunity to gather this much needed information, but they have not been extensively trialled in office workplaces, nor rigorously compared against more familiar devices such as accelerometers. The aim of this paper was to determine whether an RTLS can measure and spatially locate the non-stationary and stationary behaviours of adults working in an office work environment. Data collected from a series of comparison studies undertaken in a commercial office building suggests that RTLS can measure the velocity at which people are moving and locate them, when stationary, with an accuracy of 0.668 m (SD 0.389). This opens up significant opportunities to further understand how people move within buildings, the indoor physical environmental influences on that movement, and the development of effective interventions to help people to move more whilst at work.

Development of a bioclimatic wind rose tool for assessment of comfort wind resources in Sydney, Australia for 2013 and 2030.

This study assessed the effect of wind on human thermal comfort by preforming outdoor urban climatic comfort simulations using state-of-the-art heat-balance models of human thermo-physiology (Universal Thermal Climate Index-UTCI). A series of simulations for computing "wind cooling potential" have been performed using the UTCI index temperatures. The comfort cooling effect of wind has been estimated by modelling with wind taken into account, and under calm wind (0.05 m/s) (ΔUTCI). A novel wind rose biometeorological data visualisation tool that integrates an additional thermal comfort dimension into the conventional climatology wind rose visualisation was developed in this study. The new wind rose graphic tool identifies "predominant" wind directions, and whether or not they are "desirable" from the human thermal comfort point of view. This tool's utility lies in its identification of the optimal building orientation in its surrounding urban morphology, based on the cooling potential of wind resources when enhanced ventilation is desirable for thermal comfort.

Outdoor thermal physiology along human pathways: a study using a wearable measurement system.

An outdoor summer study on thermal physiology along subjects' pathways was conducted in a Japanese city using a unique wearable measurement system that measures all the relevant thermal variables: ambient temperature, humidity, wind speed (U) and short/long-wave radiation (S and L), along with some physio-psychological parameters: skin temperature (T skin), pulse rate, subjective thermal sensation and state of body motion. U, S and L were measured using a globe anemo-radiometer adapted use with pedestrian subjects. The subjects were 26 healthy Japanese adults (14 males, 12 females) ranging from 23 to 74 years in age. Each subject wore a set of instruments that recorded individual microclimate and physiological responses along a designated pedestrian route that traversed various urban textures. The subjects experienced varying thermal environments that could not be represented by fixed-point routine observational data. S fluctuated significantly reflecting the mixture of sunlit/shade distributions within complex urban morphology. U was generally low within urban canyons due to drag by urban obstacles such as buildings but the subjects' movements enhanced convective heat exchanges with the atmosphere, leading to a drop in T skin. The amount of sweating increased as standard effective temperature (SET*) increased. A clear dependence of sweating on gender and body size was found; males sweated more than females; overweight subjects sweated more than standard/underweight subjects. T skin had a linear relationship with SET* and a similarly clear dependence on gender and body size differences. T skin of the higher-sweating groups was lower than that of the lower-sweating groups, reflecting differences in evaporative cooling by perspiration.

Validation of the Fiala multi-node thermophysiological model for UTCI application.

The important requirement that COST Action 730 demanded of the physiological model to be used for the Universal Thermal Climate Index (UTCI) was its capability of accurate simulation of human thermophysiological responses across a wide range of relevant environmental conditions, such as conditions corresponding to the selection of all habitable climates and their seasonal changes, and transient conditions representing the temporal variation of outdoor conditions. In the first part of this study, available heat budget/two-node models and multi-node thermophysiological models were evaluated by direct comparison over a wide spectrum of climatic conditions. The UTCI-Fiala model predicted most reliably the average human thermal response, as shown by least deviations from physiologically plausible responses when compared to other models. In the second part of the study, this model was subjected to extensive validation using the results of human subject experiments for a range of relevant (steady-state and transient) environmental conditions. The UTCI-Fiala multi-node model proved its ability to predict adequately the human physiological response for a variety of moderate and extreme conditions represented in the COST 730 database. The mean skin and core temperatures were predicted with average root-mean-square deviations of 1.35 ± 1.00°C and 0.32 ± 0.20°C, respectively.

UTCI--why another thermal index?

Existing procedures for the assessment of the thermal environment in the fields of public weather services, public health systems, precautionary planning, urban design, tourism and recreation and climate impact research exhibit significant shortcomings. This is most evident for simple (mostly two-parameter) indices, when comparing them to complete heat budget models developed since the 1960s. ISB Commission 6 took up the idea of developing a Universal Thermal Climate Index (UTCI) based on the most advanced multi-node model of thermoregulation representing progress in science within the last three to four decades, both in thermo-physiological and heat exchange theory. Creating the essential research synergies for the development of UTCI required pooling the resources of multidisciplinary experts in the fields of thermal physiology, mathematical modelling, occupational medicine, meteorological data handling (in particular radiation modelling) and application development in a network. It was possible to extend the expertise of ISB Commission 6 substantially by COST (a European programme promoting Cooperation in Science and Technology) Action 730 so that finally over 45 scientists from 23 countries (Australia, Canada, Israel, several Europe countries, New Zealand, and the United States) worked together. The work was performed under the umbrella of the WMO Commission on Climatology (CCl). After extensive evaluations, Fiala's multi-node human physiology and thermal comfort model (FPC) was adopted for this study. The model was validated extensively, applying as yet unused data from other research groups, and extended for the purposes of the project. This model was coupled with a state-of-the-art clothing model taking into consideration behavioural adaptation of clothing insulation by the general urban population in response to actual environmental temperature. UTCI was then derived conceptually as an equivalent temperature (ET). Thus, for any combination of air temperature, wind, radiation, and humidity (stress), UTCI is defined as the isothermal air temperature of the reference condition that would elicit the same dynamic response (strain) of the physiological model. As UTCI is based on contemporary science its use will standardise applications in the major fields of human biometeorology, thus making research results comparable and physiologically relevant.

Effect of cabin ventilation rate on ultrafine particle exposure inside automobiles.

We alternately measured on-road and in-vehicle ultrafine (<100 nm) particle (UFP) concentration for 5 passenger vehicles that comprised an age range of 18 years. A range of cabin ventilation settings were assessed during 301 trips through a 4 km road tunnel in Sydney, Australia. Outdoor air flow (ventilation) rates under these settings were quantified on open roads using tracer gas techniques. Significant variability in tunnel trip average median in-cabin/on-road (I/O) UFP ratios was observed (0.08 to approximately 1.0). Based on data spanning all test automobiles and ventilation settings, a positive linear relationship was found between outdoor air flow rate and I/O ratio, with the former accounting for a substantial proportion of variation in the latter (R(2) = 0.81). UFP concentrations recorded in-cabin during tunnel travel were significantly higher than those reported by comparable studies performed on open roadways. A simple mathematical model afforded the ability to predict tunnel trip average in-cabin UFP concentrations with good accuracy. Our data indicate that under certain conditions, in-cabin UFP exposures incurred during tunnel travel may contribute significantly to daily exposure. The UFP exposure of automobile occupants appears strongly related to their choice of ventilation setting and vehicle.

Effect of temperature on mortality during the six warmer months in Sydney, Australia, between 1993 and 2004.

Studies of heat-related mortality have been predominantly based on analyses of underlying cause of death as the single indicator of a population's vulnerability to high temperatures. Examination of both underlying and associated causes of death could provide a more comprehensive understanding of the population at risk. This study analyzes the impact of high temperatures on mortality in Sydney, Australia, during the warmer six months (October-March) between 1993 and 2004, using the underlying and associated cause of death due to all-cause, circulatory, and respiratory disease. Some mortality datasets were also divided into two age groups, 0-64 and 65+. A generalized linear model assuming negative binomial distribution was constructed for the daily mortality counts using daily maximum temperature and hourly maximum concentrations of ozone (O3) and particulate matter (PM10) as covariates. With the air pollution terms in a model, the change in mortality was estimated to be between 4.5% and 12.1% for a 10 degrees C increase in maximum daily temperature, depending on mortality dataset. When air pollutants were removed from a model, the above mortality percentages changed by -1.1% to 0.9%. When both underlying and associated causes of death were considered, the effect remained the same or became lower. Maximum temperature has been found to have a significant effect on mortality in Sydney, with PM10 and O3 confounding the association.

Synoptic analysis of heat-related mortality in Sydney, Australia, 1993-2001.

Exposure to extremely hot weather has been associated with increased mortality. Temporal Synoptic Index is an effective method used to analyze the relationship between mortality and combined weather factors. The aim of this study is to examine the short-term effect of ambient heat on mortality in Sydney during the warmest 6-month period (October-March) for the years 1993-2001. Eleven synoptic categories were related to daily mortality rates in Sydney. Two distinctive warm categories were associated with significantly higher mortality rates. Hot, dry and relatively rare Synoptic Category 7 (SC7) days showed the highest daily mortality rates, followed by warm and humid SC3 days, which occurred more frequently. Increased mortality was more pronounced among the elderly population, and gender-stratified analysis showed women to be more vulnerable. Mortality on the day of the weather event was higher than 1 or 2 days after the adverse synoptic situation. Ozone and particulate matter smaller than 10 microm were found at high concentrations in SC3 and SC7, respectively, but their impact on mortality was not clear. The population of Sydney was found to be vulnerable to high temperatures, with a lower susceptibility than those of some cities in the USA and Europe.

A synoptic climatology of pollen concentrations during the six warmest months in Sydney, Australia.

This paper takes an air mass approach to investigating the influence of weather on pollen concentrations in the atmosphere in Sydney, Australia, by producing a synoptic classification of pollen concentrations measured in the Sydney Basin. This synoptic classification has been produced using multivariate statistical techniques including principal component analysis and cluster analysis, to assign days into meteorologically homogenous categories. Surface and upper air meteorological data for warm months (October-March) over a 10-year period were used as input into the statistical analyses. Eleven synoptic categories were found in Sydney during the warm months. Pollen concentrations for the total pollen load and five individual families measured over a 3.5-year period have been investigated for each of the synoptic categories. High pollen concentrations during the warm months in Sydney are found to be influenced by the presence of a region of low surface pressure located to the south of the continent, bringing fast dry westerly gradient winds to Sydney. It is envisaged that these results will be important from a pollen forecast and associated public health perspective.