Aspects Of Thermal Comfort Research Articles

Redeveloping industrial buildings for residential use: Energy and thermal comfort aspects

The old industrial buildings, now located near the city centres, redeveloping into commercial or residential use is very popular, but energy and especially comfort conditions not analysed because usually the specific projects are not made. This article provides an analysis of various aspects of energy demand and indoor thermal comfort when old, often unused industrial buildings are redeveloped for residential use. The results of the analysis, if the buildings are in use, show such redevelopment to be very efficient in terms of saving energy resources. In order to analyse thermal comfort of the redeveloped building, two different heating systems, radiator heating and floor heating, were examined. The performance of these systems was analysed with respect to three different room heights and window-to-wall ratios (hereinafter referred to as WWR). In order to simulate temperature distribution, computational fluid dynamics (hereinafter referred to as CFD) software SolidWorks®FlowSimulation was used. The results of the research demonstrate the acceptability of the heating systems in terms of indoor climate and thermal comfort as well as facilitate further discussion for future research in the field.

Green walking networks for climate change adaptation

Climate change (CC) potentially affects people travel behaviour, due to extreme weather conditions. This is particularly true for pedestrians, that are more exposed to weather conditions. Introducing the effect of this change in transport modelling allows to analyse and plan walking networks taking into consideration the climatic variable. The aim of this work is to develop a tool that can support planning and design of walking networks, by assessing the effects of actions oriented to increase resilience with respect to extreme weather conditions (CC adaptation).An integrated approach is used, thus combining transport and land-use planning concepts with elements of outdoor thermal comfort and network accessibility. Walking networks are analysed through centrality indexes, including thermal comfort aspects into a general cost function of links and weighted nodes. The method has been applied to the walking network inside the Campus of the University of Catania (Italy), which includes different functions and where pedestrian paths are barely used by people. Results confirm that this tool is sensitive to the variables representing weather conditions and it can measure the influence of CC adaptation measures (e.g. vegetation) on walking attitude and on the performance of the walking network.

Multi-objective optimization for existing buildings retrofitting under government subsidization

The refurbishment of existing buildings allows remarkable improvements in energy performance, even by mature and off‐the‐shelf technologies. However, the pursuit of nearly zero energy buildings in renovation can lead to non-optimal solutions in terms of comfort. Besides, the initial cost can limit the owner in refurbishing buildings or drive the choice toward energy-efficiency measures with minimum initial cost at the expense of energy and non-energy performances. In this regard, financial incentives can be a key driver to stimulate renovation, mobilizing private investments and overcoming the high upfront costs and relatively long pay-back time of the retrofit. In the literature, the real effectiveness of incentives to improve both the comfort and the energy performance of the cost-optimal solutions has not been assessed in depth. This work investigates to which extent the incentives on different typologies of energy-efficiency measures can improve the performance of the optimal retrofits solutions. The analysis has been carried out on a set of different residential building modules, representative of different building typologies and Italian construction periods, located in two different climatic contexts representative of Italy, mixed-humid (Milano) and warm-marine (Messina) (ASHRAE 2007), optimizing the energy, costs, and indoor thermal comfort aspects.

Environment in poultry production covered with thermal and aluminum roofing tiles

Brazil is a country of tropical climate, a fact that hinders the poultry production in the aspect of thermal comfort. Thus, we aimed to evaluate the thermal environment in commercial poultry houses with different covers during the months of December 2012 to May 2013, in the municipality of Rio Verde, Goiás. The experimental design was completely randomized in split plots with factorial arrangement of treatments 2x3, being two shed models (thermal and aluminum roof tiles) and three sections within each shed (initial, central and final) for 182 days, having the days as replicates. The thermal environment was assessed through thermal comfort indices: Temperature and Humidity Index, Black Globe Temperature and Humidity Index, Radiant Heat Load and Enthalpy. The data was analyzed by SISVAR 5.1., through the analysis of variance, the Scott Knott test used to compare the means, considering a significance level of 1%. The results showed a significant statistical difference between the sheds and the points assessed (P < 0.05). The thermal shed had the lowest values for the environmental variables (Dbt and Bgt) and thermal indices studied, but larger values for the RH compared to the shed with aluminum covering. The use of thermal covers minimizes the difference in temperature range throughout various times of the day, being at 14:00 o'clock the prominence time to others.

Street greenery and its physical and psychological impact on thermal comfort

This study focuses on the benefits of street greenery for creating thermally comfortable streetscapes in moderate climates. It reports on investigations on the impact of street greenery on outdoor thermal comfort from a physical and psychological perspective. For this purpose, we examined nine streets with comparable geometric configurations, but varying amount of street greenery (street trees, front gardens) in the city of Utrecht, the Netherlands. Mobile micrometeorological measurements including air temperature (Ta), solar and thermal radiation were performed, enabling the calculation of mean radiant temperature (Tmrt). Additionally, semi-structured interviews with pedestrians about their momentary and long-term perceived thermal comfort and their esthetical appreciation of the green street design were conducted. Measurements showed a clear impact (p=0.0001) of street greenery on thermal comfort through tree shading: 10% tree crown cover within a street canyon lowered street averaged Tmrt about 1K. In contrast, our results did not show an influence of street greenery on street averaged Ta. Interview results indicated that momentary perceived thermal comfort tended to be related to the amount of street greenery. However, the results were not statistically significant. Related to long-term perceived thermal comfort respondents were hardly consciously aware of influences by street greenery. Yet, people significantly (p<0.001) valued the presence of street greenery in esthetic terms. In conclusion, street greenery forms a convenient adaptive strategy to create thermally comfortable and attractive living environments. Our results clearly indicate that both physical and psychological aspects of thermal comfort have to be considered in urban design processes.

Component Analysis of Thermally Activated Building System in Residential Buildings

The packaged terminal air conditioner, the typical cooling system for the residential buildings, consumes a large amount of electricity in a short period time during peak hours. In order to reduce the peak load and conserve the electricity, the thermally activated building system can be used as a secondary system to handle the partial cooling load. However, the thermally activated building system may cause condensation and under-cooling. Thus, design of both systems should be performed with careful investigation in characteristics of both systems to amplify the advantages. Since the thermally activated building system has the time-delay effect which may cause under-cooling, the system is designed to handle the base load of the building. Hence, simple simulation with EnergyPlus was performed to observe the characteristics of cooling load in residential buildings. Once the possible range of the load handling ratio of the thermally activated building system was decided, characteristics of system was analyzed in terms of hardware component and operation parameters. The hardware components were analyzed in plant and system aspects and the operation parameter was evaluated in the thermal comfort aspect. As the load handling ratio increased, the thermal comfort increased due to the lower radiant mean temperatures. Within the range of thermal comfort, the several adjustments were made in setpoint temperature and electricity consumptions of difference cases were observed to decide which components and parameters were important for designing the systems.

A Perspective of the Diurnal Aspect of Thermal Comfort in Nigeria

This study examines the day-time variations in the physiologic comfort of Nigeria using the effective temperature, temperature-humidity and relative strain indices (ETI, THI and RSI, respectively) for 59 years (1951-2009) at 20 well-distributed (2 by 2°) meteorological stations across Nigeria. It also examines the responses from 3600 sample population from tertiary institutions across Nigeria. Results indicated thermal stress in Nigeria, and showed that both heat and cold stress varied temporally and spatially (1200 - 1500 Local Standard Time, LST as the most thermally uncomfortable period of the day, while before 0900 and around 2100 LST were more comfortable). The study showed that judgment on climate issues were often beclouded by religious or ignorant sentiments. Efficient coping strategies for thermal stress are generally lacking, being limited by poor education, financial capacity and inadequate government commitment to cater for the health effects of extreme climate conditions. The study concluded that Nigeria, which exemplifies many developing countries, is not yet prepared for the effect of future climate change. The study recommends climate education, improves health schemes for climate-related morbidity and improves greening of the urban environment.

Modern Housing Tranquillity in Malaysia from the Aspect of Thermal Comfort for Humid Hot Climate Zone

Development of housing is imperative to enhance the society’s standard of living in this country. The factor of occupant comfort is the main element to indicate whether the housing is successful or not. In this writing, the thermal comfort discussed in only relating to the thermal comfort zone in Malaysia and the results from the study of the internal temperature of modern houses from previous researchers. Results by a few researchers found that modern houses are currently not reaching a good level of thermal comfort to live in and the designs are not capable to resolve the issue of discomfort in the internal environment of the houses in Malaysia. Therefore, thermal comfort is one of the important aspects of research in the development of modern housing because it plays a very important role in enhancing welfare, health and the quality of life or urban society.

Assessing Impact of Material Transition and Thermal Comfort Models on Embodied and Operational Energy in Vernacular Dwellings (India)

Vernacular dwellings are well-suited climate-responsive designs that adopt local materials and skills to support comfortable indoor environments in response to local climatic conditions. These naturally-ventilated passive dwellings have enabled civilizations to sustain even in extreme climatic conditions. The design and physiological resilience of the inhabitants have coevolved to be attuned to local climatic and environmental conditions. Such adaptations have perplexed modern theories in human thermal-comfort that have evolved in the era of electricity and air-conditioned buildings. Vernacular local building elements like rubble walls and mud roofs are given way to burnt brick walls and reinforced cement concrete tin roofs. Over 60% of Indian population is rural, and implications of such transitions on thermal comfort and energy in buildings are crucial to understand. Types of energy use associated with a buildings life cycle include its embodied energy, operational and maintenance energy, demolition and disposal energy. Embodied Energy (EE) represents total energy consumption for construction of building, i.e., embodied energy of building materials, material transportation energy and building construction energy. Embodied energy of building materials forms major contribution to embodied energy in buildings. Operational energy (OE) in buildings mainly contributed by space conditioning and lighting requirements, depends on the climatic conditions of the region and comfort requirements of the building occupants. Less energy intensive natural materials are used for traditional buildings and the EE of traditional buildings is low. Transition in use of materials causes significant impact on embodied energy of vernacular dwellings. Use of manufactured, energy intensive materials like brick, cement, steel, glass etc. contributes to high embodied energy in these dwellings. This paper studies the increase in EE of the dwelling attributed to change in wall materials. Climatic location significantly influences operational energy in dwellings. Buildings located in regions experiencing extreme climatic conditions would require more operational energy to satisfy the heating and cooling energy demands throughout the year. Traditional buildings adopt passive techniques or non-mechanical methods for space conditioning to overcome the vagaries of extreme climatic variations and hence less operational energy. This study assesses operational energy in traditional dwelling with regard to change in wall material and climatic location. OE in the dwellings has been assessed for hot-dry, warm – humid and moderate climatic zones. Choice of thermal comfort models is yet another factor which greatly influences operational energy assessment in buildings. The paper adopts two popular thermal-comfort models, viz., ASHRAE comfort standards and TSI by Sharma and Ali to investigate thermal comfort aspects and impact of these comfort models on OE assessment in traditional dwellings. A naturally ventilated vernacular dwelling in Sugganahalli, a village close to Bangalore (India), set in warm – humid climate is considered for present investigations on impact of transition in building materials, change in climatic location and choice of thermal comfort models on energy in buildings. The study includes a rigorous real –time monitoring of the thermal performance of the dwelling. Dynamic simulation models validated by measured data have also been adopted to determine the impact of the transition from vernacular to modern material-configurations. Results of the study and appraisal for appropriate thermal comfort standards for computing operational energy has been presented and discussed in this paper.

The effect of internal environmental quality on occupant satisfaction in commercial office buildings

This article addresses a post-occupancy evaluation of a sample of office buildings in Adelaide, South Australia, which compares Green Star-rated against non-Green Star-rated buildings. Internal environment monitoring and occupant surveys were conducted to assess the perceived thermal, visual, and aural comforts, as well as health and productivity. The results show that Green Star-rated buildings provide slightly higher satisfaction in some thermal comfort aspects, but lower satisfaction in a number of significant elements, such as lighting and noise. Current trends in office design are, in some cases, seen to accentuate these issues. The results indicate that improvement in the design of buildings is an ongoing process that needs to be supported with effective and comprehensive feedback systems, including evaluation of the product in use, a system that is currently lacking in the commercial built environment.

Experiences from nine passive houses in Sweden – Indoor thermal environment and energy use

This paper presents experiences from a recently built area with passive houses in Linköping, Sweden and compares them with conventional buildings, mainly from an indoor environment perspective, but also based on energy use. The built area consists of 39 recently constructed terraced houses, of which nine are built according to the passive house standard. The aspects of thermal comfort as well as local discomfort are studied. The methodology is based on on-site measurements and two types of simulations – CFD and Building Energy Simulation. In addition a post-occupancy evaluation was made using a standardized questionnaire to relate the occupant's perception of the indoor environment one year after the buildings were completed.The thermal comfort for these newly built passive houses is well within the limits in the local building code. However, some interesting findings related to local comfort such as cold floors are found in the post-occupancy evaluation as well as in the predictions. The occupants of the passive houses experience cold floors to a higher degree than in the conventional buildings. It was also shown that there are a higher number of complaints related to high temperatures during summer in the passive houses. It is worth noting that the buildings do not have external shading installed by default. The effect of varying temperatures was also observed in the passive houses to a higher degree than in the more conventional buildings, especially related to cooking and other heat-generating activities, which is normal in a more well insulated and airtight building.

SUSTAINABLE ARCHITECTURAL DESIGN IN A TRADI-TIONAL BALINESE HOUSING IN ACCORDANCE TO THE CONCEPT OF TRI MANDALA

Global challenges such as natural resource depletions, irregular weather pattern, and pollutions were imminent. The Home Green Design proposed by other countries was not suitable to Bali Island because of the local social context. The Balinese House is regulated with the Tri Mandala and Sanga Mandala to achieve the harmonious relations between Macrocosms (Bhuana Agung) and Microcosms (Bhuana Alit) [or Tri Hita Karana]. The Sanga Mandala guides the spatial pattern both on the house and the settlement scale. The Tenganan traditional Village implemented Tri-Mandala which organized the house into the Utama (upper and sacred), Madya (middle and human), and Nista (lower and profane). The Tri Mandala concept is very adaptable to the environment, even in the middle of the economic-driven activities and fast home development. However, the Tri-Mandala really supported the sustainability in the functionality aspect, the social acceptance aspect as well as thermal comfort aspect. Therefore, the Tri Mandala concept could be implemented in the contemporary house design in Bali.

Visual and thermal comfort and its relations to exergy consumption in a classroom with daylighting

This paper discusses the exergetic aspect of daylighting together with luminous and thermal comfort aspect. We calculated the exergy consumption for lighting and cooling in a classroom for the cases with and without electric lighting. The full use of daylighting decreases chemical exergy input to the power plant by 89%. According to a questionnaire survey asking the students' perception of sensations and comfort in the classroom, while daylighting was being used, the cut–off of fluorescent tubes did not cause any luminous discomfort and it made their thermal comfort even better.

Outdoor thermal comfort and outdoor activities: A review of research in the past decade

Outdoor spaces are important to sustainable cities because they accommodate pedestrian traffic and outdoor activities, and contribute greatly to urban livability and vitality. In the global context of climate change, outdoor spaces that provide a pleasurable thermal comfort experience for pedestrians effectively improve the quality of urban living. The influence of thermal comfort on outdoor activities is a complex issue comprising both climatic and behavioral aspects; however, current investigations lack a general framework for assessment. This paper presents a review of research over the past decade on the behavioral aspects of outdoor thermal comfort. The article focuses on perceptions of outdoor thermal comfort and the use of outdoor space in the context of urban planning. We further discuss a general framework for assessing outdoor thermal comfort based on behavioral aspects and the need for predicting tools in the design and planning of outdoor thermal comfort.

Identification of Indoor Environmental Quality (IEQ) Parameter in Creating Conducive Learning Environment for Architecture Studio

This paper discusses aspects of the literature considered in the Indoor Environmental Quality (IEQ) to study in the architecture studio. Studio-Based Learning (PBS) has been widely practiced for the architecture program and is emphasized as one of the learning needs for the purpose of design ideas. Indoor environmental quality includes thermal comfort, ventilation, noise, suspended materials in the air and the chemical content composition. For the architecture studio, aspect of thermal comfort is taken into account, with the additional parameters of air quality, disturbances, control, appearance, general atmosphere and lighting.

Using the adaptive model of thermal comfort for obtaining indoor neutral temperature: Findings from a field study in Hyderabad, India

There is a dearth of thermal comfort studies in India. It is aimed to investigate into the aspects of thermal comfort in Hyderabad and to identify the neutral temperature in residential environments. This was achieved through a thermal comfort field study in naturally ventilated apartment buildings conducted during summer and monsoon involving over 100 subjects. A total of 3962 datasets were collected covering their thermal responses and the measurement of the thermal environment. The comfort band (voting within –1 and +1), based on the field study, was found to be 26–32.45°C, with the neutral temperature at 29.23°C. This is way above the indoor temperature standards specified in Indian Codes. It was found that the regression neutral temperature and the globe temperature recorded when voting neutral converged when mean thermal sensation of the subjects was close to 0. This happened during the period of moderate temperature when the adaptive measures were adequate. The indoor temperatures recorded in roof-exposed (top floor) flats were higher than the lower floors. The thermal sensation and preference votes of subjects living in top floors were always higher. Consequently, their acceptance vote was also lower. It was found that the subjects living in top floor flats had a higher neutral temperature when the available adaptive opportunities were sufficient. This was due to their continuous exposure to a higher thermal regime due to much higher solar exposure. This study calls for special adaptive measures for roof-exposed flats to achieve neutrality at higher temperature.

Performance Analyse of Air Mixed and Displacement Ventilatilation System in Office Room Base on Computational Fluid Dynamic

Air ventilation system is required for improvement as well as maintenance room air circumstance which is always clean in the whole day. Effective ventilation will enhance thermal comfort and indoor air quality therefore the productivity of occupant is expected also becomes mo-re intense. This research deals with the influence of supply air diffuser position concerning to thermal comfort and in-door air quality viewpoints. It is inspected four categories of air ventilation system: mixed and displacement ventila-tion used for air supply diffuser position in the centre and at the side of the room. Thermal comfort aspect is demons-trated through velocity and temperature of the room air without considering the value of relative humidity and room surface temperature average). On the other side the indoor air quality is focused on the intensity of the CO2 gas concentration which is appear inside the room gas. It applies Fluent 6.2 as computational fluid dynamics (CFD) simulation, some research variables are exploited. Office room model is generated in GAMBIT software create par-ticular office room design. Analyse result prove that the displacement centre ventilation system has more capability in the handling of room heat in addition to contaminant gas compare to the others.

Effects of thermal activated building systems in schools on thermal comfort in winter

There is a growing attention for the Indoor Air Quality problems in schools, but there is far less attention for the thermal comfort aspects within schools. A literature review is done to clear the effects of thermal quality in schools on the learning performance of the students: it clearly shows that thermal environment is like IAQ of great influence to the students' performance. As many studies focus on the ventilation aspects we focus more on the thermal comfort of the schools through measurements and questioners held in 14 schools equipped with different types of ventilation and heating systems. A new approach to design adequate thermal comfort solutions for school buildings was developed during the last years: Thermo Active Building Systems, which uses thermo activated concrete. In three new schools with Thermo Active Building Systems thermal comfort was determined through measurements and questionnaires and compared with that of 11 schools more traditional heating systems

CFD simulation for the improvement of thermal comfort

Thermal comfort is an important criterion when choosing a car and, for this reason, it has assumed a high priority in vehicle design. In order to assess comfort not only qualitatively but also quantitatively, Ferrari, in close co operation with the University of Pisa (Italy), has defined thermal comfort indices and made comprehensive evaluations of the general aspects of thermal comfort. For various reasons, an experimental approach is not practical, especially for the thermo-aerodynamic evaluations required. The calculations were therefore performed using the Computational Fluid Dynamics (CFD) software Fluent from Ansys.

CFD simulation for the improvement of thermal comfort in cars

Thermal comfort is an important criterion when choosing a car and, for this reason, it has assumed a high priority in vehicle design. In order to assess comfort not only qualitatively but also quantitatively, Ferrari, in close cooperation with the University of Pisa (Italy), has defined thermal comfort indices and made comprehensive evaluations of the general aspects of thermal comfort. For various reasons, an experimental approach is not practical, especially for the thermo-aerodynamic evaluations required. The calculations were therefore performed using the Computational Fluid Dynamics (CFD) software Fluent from Ansys.