As people age, physiological changes affect their thermal perception, sensitivity and regulation. The ability to respond effectively to temperature fluctuations is compromised with physiological ageing, upsetting the homeostatic balance of health in some. As a result, older people can become vulnerable at extremes of thermal conditions in their environment. With population ageing worldwide, it is an imperative that there is a better understanding of older people’s thermal needs and preferences so that their comfort and wellbeing in their living environment can be optimised and healthy ageing achieved. However, the complex changes affecting the physiological layers of the individual during the ageing process, although largely inevitable, cannot be considered linear. They can happen in different stages, speeds and intensities throughout the ageing process, resulting in an older population with a great level of heterogeneity and risk. Therefore, predicting older people’s thermal requirements in an accurate way requires an in-depth investigation of their individual intrinsic differences. This paper discusses an exploratory study that collected data from 71 participants, aged 65 or above, from 57 households in South Australia, over a period of 9 months in 2019. The paper includes a preliminary evaluation of the effects of individual intrinsic characteristics such as sex, body composition, frailty and other factors, on thermal comfort. It is expected that understanding older people’s thermal comfort from the lens of these diversity-causing parameters could lead to the development of individualised thermal comfort models that fully capture the heterogeneity observed and respond directly to older people’s needs in an effective way. (article starts at page 13)
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In 2004 the first adaptive thermal comfort guideline was introduced in the Netherlands. Recently a new, upgraded version of this ISSO 74 (ATG) guideline has been developed. The new requirements are hybrid in nature as the 2014 version of the guideline combines elements of traditional non-adaptive comfort standards with elements of adaptive standards. This paper describes the new guideline and explains the rationale behind it. Also changes in comparison with the original 2004 version and issues related to performance verification are discussed. The information presented in this paper can be used by others (other countries) as inspiration material for other new adaptive comfort guidelines and standards.
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Thermal comfort is determined by the combined effect of the six thermal comfort parameters: temperature, air moisture content, thermal radiation, air relative velocity, personal activity and clothing level as formulated by Fanger through his double heat balance equations. In conventional air conditioning systems, air temperature is the parameter that is normally controlled whilst others are assumed to have values within the specified ranges at the design stage. In Fanger’s double heat balance equation, thermal radiation factor appears as the mean radiant temperature (MRT), however, its impact on thermal comfort is often ignored. This paper discusses the impacts of the thermal radiation field which takes the forms of mean radiant temperature and radiation asymmetry on thermal comfort, building energy consumption and air-conditioning control. Several conditions and applications in which the effects of mean radiant temperature and radiation asymmetry cannot be ignored are discussed. Several misinterpretations that arise from the formula relating mean radiant temperature and the operative temperature are highlighted, coupled with a discussion on the lack of reliable and affordable devices that measure this parameter. The usefulness of the concept of the operative temperature as a measure of combined effect of mean radiant and air temperatures on occupant’s thermal comfort is critically questioned, especially in relation to the control strategy based on this derived parameter. Examples of systems which deliver comfort using thermal radiation are presented. Finally, the paper presents various options that need to be considered in the efforts to mitigate the impacts of the thermal radiant field on the occupants’ thermal comfort and building energy consumption.
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In indoor comfort research, thermal comfort of care-professionals in hospital environment is a little explored topic. To address this gap, a mixed methods study, with the nursing staff in hospital wards acting as participants,was undertaken. Responses were collected during three weeks in the summer (n = 89), and four weeks in the autumn (n = 43). Analysis of the subjective feedback from nurses and the measured indoor thermal conditions revealed that the existent thermal conditions (varying between 20 and 25 °C) caused a slightly warm thermal sensation on the ASHRAE seven point scale. This led to a slightly unacceptable thermal comfort and a slightly obstructed self-appraised work performance. The results also indicated that the optimal thermal sensation for the nurses—suiting their thermal comfort requirements and work performance—would be closer to‘slightly cool’than neutral. Using a design approach of dividing the hospital ward into separate thermal zones, with different set-points for respectively patient and care-professionals’comfort, would seem to be the ideal solution that contributes positively to the work environment and, at the same time, creates avenues for energy conservation.
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In operatiekamers heeft de luchtkwaliteit vanzelfsprekend de meeste aandacht in verband met het risico op postoperatieve wondinfecties bij de patiënt. Echter het belang van thermisch comfort moet niet onderschat worden. In dit onderzoek wordt subjectief (perceptie) en objectief (metingen) de situatie onderzocht in operatiekamers met verschillende ventilatiesystemen. Uitgangspunt is een vergelijk met de theorie.
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As a consequence of climate change and urbanization, many cities will have to deal with more flooding and extreme heat stress. This paper presents a framework to maximize the effectiveness of Nature-Based Solutions (NBS) for flood risk reduction and thermal comfort enhancement. The framework involves an assessment of hazards with the use of models and field measurements. It also detects suitable implementation sites for NBS and quantifies their effectiveness for thermal comfort enhancement and flood risk reduction. The framework was applied in a densely urbanized study area, for which different small-scale urban NBS and their potential locations for implementation were assessed. The overall results show that the most effective performance in terms of flood mitigation and thermal comfort enhancement is likely achieved by applying a range of different measures at different locations. Therefore, the work presented here shows the potential of the framework to achieve an effective combination of measures and their locations, which was demonstrated on the case of the Sukhumvit area in Bangkok (Thailand). This can be particularly suitable for assessing and planning flood mitigation measures in combination with heat stress reduction.
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Purpose: This field study analyses the quality of the actual thermal comfort and indoor air quality in Dutch office buildings. A linear regression analysis was used to determine how much these variables and demographic variables influenced the perceived thermal comfort of office workers.Approach: Data were collected on-spot at two Dutch office buildings (n=182) during the winter of 2015 and showed that the indoor air in these offices is of good quality and did not affect the perceived thermal comfort significantly. The indoor temperature was the most important variable that influenced the perceived thermal comfort. Indoor temperatures ranged in this study from 18 till 24oC and were therefore at the edge of acceptable European and Dutch standards NPR-CR 1752 (1999), NEN-EN 15251(2007) and NEN-EN-ISO 7730 (2007).Findings: Office workers which experienced a indoor temperature of 20oC graded this temperature the highest (6.7 on a scale from 1-10). At 20oC the percentage of workers that was dissatisfied was the lowest (30%). This study also showed that female workers were more likely to have the sensation that is was too cold than male workers. European and Dutch standards prescribe that an indoor temperature between 21 and 23oC should be the most ideal temperature during wintertime. This study indicates that an indoor temperature higher than 22oC might be too warm for office workers in The Netherlands during wintertime and that application might influence office workers’ satisfaction negatively.
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Cities are confronted with more frequent heatwaves of increasing intensity discouraging people from using urban open spaces that are part of their daily lives. Climate proofing cities is an incremental process that should begin where it is needed using the most cost-efficient solutions to mitigate heat stress. However, for this to be achieved the factors that influence the thermal comfort of users, such as the layout of local spaces, their function and the way people use them needs to be identified first. There is currently little evidence available on the effectiveness of heat stress interventions in different types of urban space.The Cool Towns Heat Stress Measurement Protocol provides basic guidance to enable a full Thermal Comfort Assessment (TCA) to be conducted at street-level. Those involved in implementing climate adaptation strategies in urban areas, such as in redevelopments will find practical support to identify places where heat stress may be an issue and suggestions for effective mitigation measures. For others, such as project developers, and spatial designers such as landscape architects and urban planners it provides practical instructions on how to evaluate and provide evidence-based justification for the selection of different cooling interventions for example trees, water features, and shade sails, for climate proofing urban areas.
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Thermal comfort -the state of mind, which expresses satisfaction with the thermal environment- is an important aspect of the building design process as modern man spends most of the day indoors. This paper reviews the developments in indoor thermal comfort research and practice since the second half of the 1990s, and groups these developments around two main themes; (i) thermal comfort models and standards, and (ii) advances in computerization. Within the first theme, the PMV-model (Predicted Mean Vote), created by Fanger in the late 1960s is discussed in the light of the emergence of models of adaptive thermal comfort. The adaptive models are based on adaptive opportunities of occupants and are related to options of personal control of the indoor climate and psychology and performance. Both models have been considered in the latest round of thermal comfort standard revisions. The second theme focuses on the ever increasing role played by computerization in thermal comfort research and practice, including sophisticated multi-segmental modeling and building performance simulation, transient thermal conditions and interactions, thermal manikins.
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Thermal comfort in operating theatres is a less addressed research component of the in-door environment in operating theatres. The air quality naturally gets most attention when considering the risk of surgical site infections. However, the importance of thermal comfort must not be underestimated. In this research, the current thermal comfort situation of staff members is investigated. Results show that the thermal comfort for the members of a surgical team is perceived as not optimal. Application of the PMV and DR models needs further attention when applied for operating theatres. For the investigated ventilation systems, the differences in thermal comfort outcomes are small.
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