A study of adaptive thermal comfort in a well-controlled climate chamber

This paper aims to critically examine the application of Predicted Mean Vote (PMV) in an air-conditioned environment in the hot-humid climate region. Experimental studies have been conducted in a climate chamber in Chongqing, China, from 2008 to 2010. A total of 440 thermal responses from participants were obtained. Data analysis reveals that the PMV overestimates occupants' mean thermal sensation in the warm environment (PMV > 0) with a mean bias of 0.296 in accordance with the ASHRAE thermal sensation scales. The Bland–Altman method has been applied to assess the agreement of the PMV and Actual Mean Vote (AMV) and reveals a lack of agreement between them. It is identified that habituation due to the past thermal experience of a long-term living in a specific region could stimulate psychological adaptation. The psychological adaptation can neutralize occupants’ actual thermal sensation by moderating the thermal sensibility of the skin. A thermal sensation empirical model and a PMV-revised index are introduced for air-conditioned indoor environments in hot-humid regions. As a result of habituation, the upper limit effective thermal comfort temperature SET* can be increased by 1.6 °C in a warm season based on the existing international standard. As a result, a great potential for energy saving from the air-conditioning system in summer could be achieved.

Different strategies for improving summer thermal comfort in heavyweight traditional buildings

In order to exploit the passive energy potential of the building envelope, it is important to provide a right combination of insulation thickness, heat capacity and night-time ventilation. In this paper, this issue will be tackled with reference to an historic building in Catania (Southern Italy). The building was built at the end of the XIX century, and its opaque envelope is entirely made with lava stones, which is typical of traditional architecture in this area. Starting from the current configuration of the building, many hypotheses for refurbishment are considered, combined with different strategies for passive cooling, such as night-time ventilation, use of shading devices and adoption of highly-reflective coatings. The effectiveness of each solution in terms of summer thermal comfort is evaluated through dynamic thermal simulations carried out with EnergyPlus. The results show the synergic effect of these strategies, as well as their individual impact, and allow to draw some general conclusions about the behaviour of heavyweight buildings under moderately hot weather conditions.

Assessing how retrofit of traditional buildings impacts indoor environment and occupant’s thermal comfort

Buildings consume a large amount of energy, in both their use and production. Retrofitting aims to achieve a reduction in this energy consumption. However, there are concerns that retrofitting can cause negative impacts on the internal environment including poor thermal comfort and health issues. This research investigates the impact of retrofitting the façade of existing traditional buildings and the resulting impact on the indoor environment and occupant thermal comfort. A Case building located at the University of Reading has been monitored experimentally and modelled using IES software with monitored values as input conditions for the model. The proposed façade related retrofit options have been simulated and provide information on their effect on the indoor environment. The findings show a positive impact on the internal environment. The data shows a 16.2% improvement in thermal comfort after retrofit is simulated. This also achieved a 21.6% reduction in energy consumption from the existing building.

Can qualitative methods support the development of more flexible and energy saving thermal comfort?

This paper uses examples from a Swedish study to suggest some ways in which cultural variation could be included in studies of thermal comfort. It is shown how only a slight shift of focus and methodological approach could help us discover aspects of human life that add to previous knowledge within comfort research of how human beings perceive and handle warmth and cold. It is concluded that it is not enough for buildings, heating systems and thermal control devices to be energy-efficient in a mere technical sense. If these are to help to decrease, rather than to increase, energy consumption, they have to support those parts of already existing habits and modes of thought that have the potential for low energy use. This is one reason why culture-specific features and emotional cores need to be investigated and deployed into the study and development of thermal comfort.

Applying the adaptive model of comfort

This note is directed to one major aspect of the comfort of building occupants – namely, thermal comfort. Even though it may be difficult to isolate thermal sensations from the whole of comfort itself, humans have a strong physiological connection with their thermal environment. Our thermal perceptions and sensations often vary greatly, especially between our indoor and outdoor environments. We may be totally comfortable lounging under a shade cloth on a 35°C day with a stiff breeze enveloping our body, but would never tolerate similar conditions indoors. Such divergent perceptions of the same thermal stimulus across differing contexts raise countless questions about just what the determinants of thermal comfort actually are, and how they may be managed against the demands for an environmentally responsive architecture.

Effect of three wound dressings on infection, healing comfort, and cost in patients with sternotomy wounds - a randomized trial

Study objective: To compare three dressing types in terms of their ability to protect against infection and promote healing, patient comfort, and cost-effectiveness.

Design: Prospective, randomized controlled trial.

Setting: Major metropolitan, academically affiliated, tertiary referral center.

Patients: Seven hundred thirty-seven patients were randomized to receive a dry absorbent dressing (n = 243) [Primapore; Smith & Nephew; Sydney, NSW, Australia], a hydrocolloid dressing (n = 267) [Duoderm Thin ConvaTec; Mulgrave, VIC, Australia], or a hydroactive dressing (n = 227) [Opsite; Smith & Nephew] in the operating theater on skin closure.

Results: There was no difference in the rate of wound infection or wound healing between treatment groups. The Primapore dressing was the most comfortable and cost-effective dressing option for the sternotomy wound. Duoderm Thin dressings were associated with increased wound exudate (p < 0.001), poor dressing integrity (p < 0.001), more frequent dressing changes (p < 0.001), more discomfort with removal (p < 0.05), and increased cost (p < 0.001).

Conclusions: In the context of no additional benefit for the prevention of wound infection or the rate of wound healing for any of the three dressing products examined, dry absorbent dressings are the most comfortable and cost-effective products for sternotomy wounds following cardiac surgery.

Comfort letters- a fresh look?

The topic of “comfort letters” is an ongoing debate in Australia. There are arguments for and against enforceability of comfort letters, yet little has been said about how the “law” can be reformed. In support of enforceability, this article provides a comparative perspective on the American and Australian models and suggests that certain principles from the former could be adopted in Australia to eliminate the inconsistency in the treatment of comfort letter cases. The article also analyses Gate Gourmet and Lasalle Bank, two recent cases from Australia and the United States, respectively.

Towards a digital representation of physical phenomena to assess comfort in future environments

This paper presents the concept and a test implementation of a digital representation of the physical world designed to assess comfort quality in
future environments. An integrated set of physical phenomena is modeled three-dimensionally to investigate the dynamic behavior of design objects
holistically.

The formulation supports the integration of computational simulation in the performance-based design process. It employs the principles of
geometrical and physical selfcontainedness to avoid that complex geometrical and physical circumstances have to be specified at design time. The concepts of congeneric cells and congeneric conjunctions are
introduced to simulate various physical phenomena simultaneously with a uniformly structured set of equations.

The concept, the prototype implementation and selected test cases are presented. Although it was not possible to implement all features and model parts completely, the research and the discussion of its achievements make valuable contributions towards more effective integration of computational simulation in the performance-based design process.

Interpreting Fanger's comfort equation within the adaptive paradigm

This paper reviews the evolution of Fanger's heat balance equation in regard of adaptive opportunities. Heat balance and adaptive response are integrated into one model as two fundamental aspects of human-environment interaction that define thermal comfort perception, rather than being seen as two concepts of alternative comfort paradigms. The paper suggests to extent Fanger's model with a heat storage term in order to account for comfort perception under transient thermal conditions, and to review Fanger's modelling assumptions in order to allow for a greater variety of adaptive response options. In the presented model heat exchange is modulated through adaptation of physiological, environmental and behavioural parameters in the human-environment system defined through Fanger's heat exchange equations. A computational prototype is implemented to determine 'comfortable' values and ranges of the six comfort dimensions alternatively to Fanger's comfort indices. Thereby values of for example 'comfortable' clothing and metabolic rate are results rather than necessary input parameters, which are difficult to determine. This approach allows generating design advice for physical, organisational and social environments based on heat balance calculation in the six-dimensional opportunity space defined through Fanger's comfort equation. A starting point for the development of a dynamic adaptive comfort model is set.

Towards a universal and integrated digital representation of physical phenomena: a model to investigate comfort and energy efficiency in future environments

This thesis describes the exploration and the development of computational means to investigate the behaviour of design objects before they are available for investigation in the physical world. The motivation is to inform the design process about the design object's performance in order to achieve better--more performance-oriented--design outcomes in the sense of energy efficiency and comfort performance than can be achieved by conventional design techniques.

Energy use and thermal comfort in a rammed earth office building

A two-storey rammed earth building was built on the Thurgoona Campus of Charles Sturt University in Albury-Wodonga, Australia, in 1999. The building is novel both in the use of materials and equipment for heating and cooling. The climate at Wodonga can be characterised as hot and dry, so the challenge of providing comfortable working conditions with minimal energy consumption is considerable. This paper describes an evaluation of the building in terms of measured thermal comfort and energy use. Measurements, confirmed by a staff questionnaire, found the building was too hot in summer and too cold in winter. Comparison with another office building in the same location found that the rammed earth building used more energy for heating. The thermal performance of three offices in the rammed earth building was investigated further using simulation to predict office temperatures. Comparisons were made with measurements made over typical weeks in summer and winter. The validated model has been used to investigate key building parameters and strategies to improve the thermal comfort and reduce energy consumption in the building. Simulations showed that improvements could be made by design and control strategy changes.