Effect of building interface form on thermal comfort in gymnasiums in hot and humid climates

The thermal environment and thermal comfort of a building are greatly affected by the design of the building interface form. Most contemporary architectural designs consider only the relations between architectural form and architectural beauty. Few studies on the correlation of architectural form and thermal comfort address the influence of architectural form on thermal comfort and thermal environment. These studies are particularly important for gymnasium architectures located in hot and humid areas, which have high requirements for thermal comfort. This paper presents an experimental investigation and an analysis of the effect of the building interface form of gymnasiums on thermal comfort in hot and humid subtropical regions durings ummer. Results showed that the influence of the top interface forms on thermal comfort is mainly dominated by the mean radiant temperature, which could be controlled to improve thermal comfort. The influence of side interface forms on thermal comfort is mainly dominated by air velocity, and thermal comfort could be improved by promoting natural ventilation on the side interface form design to reduce indoor heat. This research enhanced our understanding of the relation between the interface form and the thermal comfort of gymnasiums. In addition, this paper provides a theoretical reference for the sustainable design of gymnasiums in hot and humid climates.     

Simulation of the urban thermal comfort in a high density tropical city: Analysis of the proposed urban construction rules for Dhaka, Bangladesh

The thermal comfort in urban canyons of a high density city is a very challenging issue for urban planners and designers, especially in hot humid tropical zone. The present study aims to evaluate the effects of a newly promulgated building construction rules in respect of thermal climate for Dhaka, Bangladesh, a region characterized by high density area with tropical climate. Three different urban canyons from three areas were considered which almost represents the whole city. Measurements were carried out to assess the existing thermal climate in the city canyons. Further, three model canyons were configured according to the new rules of ground coverage, floor area ratio (FAR) and site setback. A three-dimensional numerical model with high spatial and temporal resolution was used to investigate the microclimatic changes within the urban environments. Model calculations were run for a typical summer day. The thermal climate was evaluated based on air temperature T _a, surface temperature T _s, relative humidity RH, and wind speed in the existing and model canyons. For thermal comfort assessment the temperature humidity index (THI) was considered in this study. The results showed that the outdoor spaces of the study areas are thermally uncomfortable and the new building construction rules hardly improve the conditions in general. However, THI decreases in a canyon where sky view factor (SVF) decreases in the model canyon than the existing one. In addition, the surface temperature T _s and air temperature T _a do not show the same picture. Furthermore, the wind speed increases in all the model canyons as the site setback allows wind flow uniformly inside the canyons.     

Evaluation of adaptive thermal comfort models in moderate climates and their impact on energy use in office buildings

Thermally Activated Building Systems (TABS) are regarded as top-cooling systems rather than full air-conditioning systems. Therefore, adaptive thermal comfort models (ASHRAE55, ISSO74 or EN15251) are supposed to be applicable to TABS buildings, although the comfort model conditions are not necessarily satisfied. This paper investigates whether, for a moderate climate and with the heating and cooling set points chosen according to the adaptive models, the building’s energy use reduces. After all, applying adaptive models, if appropriate, is thought to lower energy use because higher maximum operative zone temperatures T_op,max are allowed, compared to the conventional ISO7730 model. For purpose of generality, a building with an ideal heating and cooling system is considered. Analysis of moderate climate weather data reveals a low energy reducing potential for the ASHRAE55 and ISSO74 model, because high reference outdoor temperatures hardly occur. EN15251 on the other hand, allows very high T_op,max and will lower the cooling need.A 2-zone building simulation demonstrates a higher cooling need for ASHRAE55 and ISSO74, compared to ISO7730. Because cooling is needed during the whole year, the lower winter T_op,max of these adaptive models causes these unexpected results. With real data of warmer years or varying gains, this conclusion holds.     

Outdoor thermal comfort: Analyzing the impact of urban configurations on the thermal performance of street canyons in the humid subtropical climate of Sydney

The quality of outdoor space is becoming increasingly important with the growing rate of urbanization. Visual, acoustic, and thermal balance degradation are all negative impacts associated with outdoor comfort in dense urban fabrics. Urban morphology thus needs assessment and optimization to ensure favorable outdoor thermal comfort (OTC). This study aims to evaluate the thermal performance of streets in residential zones of Liverpool, NSW, Australia, and tries to improve their comfort index (Physiological Equivalent Temperature) to reveal optimum urban configurations. This evaluation is done by investigating the following urban design factors affecting OTC using computational simulation techniques: street orientation, aspect ratio, building typology, and surface coverage. Our findings reveal that street canyon orientation is the most influential factor (46.42%), followed by aspect ratio (30.59%). Among the influential meteorological parameters (air temperature, wind speed, humidity and solar radiation), wind velocity had the most significant impact on the thermal comfort of the outdoor spaces in this coastal region, which typically experiences intense airflow. The results of our analysis can be utilized by multiple stakeholders, allowing them to understand and extract the most vital design factors which contextually influence the thermal comfort of outdoor spaces. Outdoor thermal comfort has a direct effect on the health and wellbeing of occupants of outdoor spaces.     

Survey of thermal comfort in residential buildings under natural conditions in hot humid and cold wet seasons in Nanjing

Comfort standards (ISO 7730, ASHRAE 55) specify the exact physical criteria for producing acceptable thermal environments, such as temperature, air movement, and humidity limits. These, however, are often difficult to comply with, particularly in hot humid and cold wet seasons in Nanjing, China. Changing expectations of comfort is important in evaluating comfort, since naturally conditioned buildings in Nanjing are not typically air-conditioned. For this objective, a field study was conducted during the summer of 2000 and the winter of 2001. A total of 600 participants each answered a subjective questionnaire. Analyzing these field data shows that in natural conditions, the influence of gender and age on people’s thermal sensations is insignificant compared with six main variables. In addition, people’s thermal discomfort rapidly increases along with growth in relative humidity. Further, the variation of people’s hot or cold sensations is in proportion to that of air movement, and the effect in winter is greater than that in summer. The range of acceptable temperatures in hot humid and cold wet Nanjing is between 14.14°C and 29.42°C.     

Thermal comfort of people in the hot and humid area of China—impacts of season,climate, and thermal history

We conducted a climate chamber study on the thermal comfort of people in the hot and humid area of China. Sixty subjects from naturally ventilated buildings and buildings with split air conditioners participated in the study, and identical experiments were conducted in a climate chamber in both summer and winter. Psychological and physiological responses were observed over a wide range of conditions, and the impacts of season, climate, and thermal history on human thermal comfort were analyzed. Seasonal and climatic heat acclimatization was confirmed, but they were found to have no significant impacts on human thermal sensation and comfort. The outdoor thermal history was much less important than the indoor thermal history in regard to human thermal sensation, and the indoor thermal history in all seasons of a year played a key role in shaping the subjects' sensations in a wide range of thermal conditions. A warmer indoor thermal history in warm seasons produced a higher neutral temperature, a lower thermal sensitivity, and lower thermal sensations in warm conditions. The comfort and acceptable conditions were identified for people in the hot and humid area of China.     

Prediction of infiltration rate and the effect on energy use for ice rinks in hot and humid climates

Infiltration of hot humid air into an ice rink situated in subtropical region was investigated. A recreation ice rink in Taipei was used as the building model and measurements of temperature, humidity, and pressure difference were performed for different outdoor air conditions. Sherman infiltration model was used to investigate building stack and wind effects. Altogether eight cases including four points on IIHF (International Ice Hockey Federation) fog lines were studied for optimal energy operations. Cooling and dehumidification characteristics due to air infiltration were investigated. Annual analysis on air infiltration and building energy was performed for monthly average weather conditions. Stack effect was found to be the most important factor of infiltration. The effects of seasonal temperatures could result in five times difference of infiltration rates. Wind effects were found to affect the peak infiltration rate more than 50%. The air change rate was found to be as high as 0.6 ACH due to stack and wind effects. The moisture infiltration peaked in summer season and can be more than several times of that in winter. It was also found in the investigation that the total heat load due to infiltration can be as high as 13,540 GJ/year for the ice rink studied. Operating conditions were found to reduce the total annual heat load by more than 50% under the IIHF fog lines. The results of this study will contribute to the technical literature in the design of year round ice rinks in tropical and subtropical regions.     

Influence of urban geometry on outdoor thermal comfort in a hot dry climate: A study in Fez,Morocco

There are few studies on the microclimate and human comfort of urban areas in hot dry climates. This study investigates the influence of urban geometry on outdoor thermal comfort by comparing an extremely deep and a shallow street canyon in Fez, Morocco. Continuous measurements during the hot summer and cool winter seasons show that, by day, the deep canyon was considerably cooler than the shallow one. In summer, the maximum difference was on average 6 K and as great as 10 K during the hottest days. Assessment of thermal comfort using the PET index suggests that, in summer, the deep canyon is fairly comfortable whereas the shallow is extremely uncomfortable. However, during winter, the shallow canyon is the more comfortable as solar access is possible. The results indicate that, in hot dry climates a compact urban design with very deep canyons is preferable. However, if there is a cold season as in Fez, the urban design should include some wider streets or open spaces or both to provide solar access.     

Impact of building regulations on the perceived outdoor thermal comfort in the mixed-use neighbourhood of Chennai

The population in urban areas is increasing rapidly around the world in most of the cities. In India, this growth has forced the local governments to review the planning norms regularly with the main focus of making an affordable urban living. This resulted in increasing the built density without evaluating the effect of such developments on human thermal comfort. Outdoor microclimate is one of the significant factors that determine the quality of outdoor spaces. This study investigates the potential impact of the built geometry guided by the newly published development control rules of Chennai, India on the various parameters that influence microclimate. The existing and future scenario has been modelled for three locations in a typical mixed-use neighborhood of Chennai. Further, air temperature and relative humidity were measured in three locations on a typical summer month of May 2018. The recorded data was used for validating the simulated model and calibrating the model settings. Most of the studies on outdoor thermal comfort compare a base case scenario and project future scenarios. This paper is a more realistic comparison of outdoor thermal comfort between the actual resultant built environment guided by the new Tamil Nadu Combined Development and Building Rules, 2019 for selected locations and the existing built geometry which is the outcome of revised development control rules of 2013. The study found a significant reduction of 18 C in mean radiant temperature (Tmrt) and a reduction of 12 C in Physiological Equivalent Temperature (PET) between the 2013 and the predicted built geometry as per 2019 building rules. Further the duration of extreme heat stress in the Physiological Equivalent Temperature (PET) scale show a reduction of 3 h during the day time. The study will assist urban planners and designers to include outdoor thermal comfort also as an important factor while developing building rules.     

Impact of building regulations on the perceived outdoor thermal comfort in the mixed-use neighbourhood of Chennai

The population in urban areas is increasing rapidly around the world in most of the cities.In India,this growth has forced the local governments to review the planning norms regularly with the main focus of making an affordable urban living.This resulted in increasing the built density without evaluating the effect of such developments on human thermal com-fort.Outdoor microclimate is one of the significant factors that determine the quality of out-door spaces.This study investigates the potential impact of the built geometry guided by the newly published development control rules of Chennai,India on the various parameters that influence microclimate.The existing and future scenario has been modelled for three locations in a typical mixed-use neighborhood of Chennai.Further,air temperature and relative humid-ity were measured in three locations on a typical summer month of May 2018.The recorded data was used for validating the simulated model and calibrating the model settings.Most of the studies on outdoor thermal comfort compare a base case scenario and project future scenarios.This paper is a more realistic comparison of outdoor thermal comfort between the actual resultant built environment guided by the new Tamil Nadu Combined Development and Building Rules,2019 for selected locations and the existing built geometry which is the outcome of revised development control rules of 2013.The study found a significant reduction of 18℃in mean radiant temperature(Tmrt)and a reduction of 12℃in Physiological Equiv-alent Temperature(PET)between the 2013 and the predicted built geometry as per 2019 build-ing rules.Further the duration of extreme heat stress in the Physiological Equivalent Temperature(PET)scale show a reduction of 3 h during the day time.The study will assist ur-ban planners and designers to include outdoor thermal comfort also as an important factor while developing building rules.     

A marriage of convenience: Street vendors' everyday accommodation of power in Dhaka,Bangladesh

Studies of informal street vending in the Global South often investigate grassroots resistance to formal and informal power as a collective and organised phenomenon. In our case study in the megacity of Dhaka, we show collective resistance is not possible due to an overwhelming threat from a coercive state. Informal vendors must resort to other tactics to appropriate public space to preserve their livelihoods. This is achieved by street vendors entering into locally embedded social and economic relations with agents of the state working informally to extort regular payments from them in return for access to public space. These local relations work in opposition to the neoliberalising ambitions of the state to clear and sanitise public space. Vendors look to local police and petty criminals for livelihood security rather than each other. This atomisation, reinforced by the culture of suspicion and kinship insularity, prevents vendors from organising across local boundaries to press claims for greater protection from the state. We argue that in cases where formal power is acting informally, this need to be taken into account to understand the social and economic realities of informal trade and the subsequent obstacles to collective action by the poor in cities such as Dhaka.     

The impact of temperature on mean local air age and thermal comfort in a stratum ventilated office

The influence of the supply air temperature on the mean local air age and thermal comfort of a typical individual office under stratum ventilation is investigated by a numerical method, which is validated by an experiment carried out by the authors. The results show that for an office, when the supply air temperature is increased from 19 °C to 21 °C, the corresponding mean occupied zone temperature rises from 24.5 °C to 26.5 °C. The inhaled air quality for the occupant is improved when supply air temperature rises from 19 °C to 21 °C. Also, the thermal comfort indices (predicted mean vote or PMV, predicted percentage of dissatisfied or PPD and predicted dissatisfied or PD) fulfill the requirements of ISO 7730 and CR 175 1998. For summer cooling operation, stratum ventilation may offer a feasible solution to elevated indoor temperatures, which are recommended by several governments in East Asia.     

夏热冬暖地区商场冬季室内热舒适研究

以广州某大型综合商场为研究对象,采用问卷调查和现场测试相结合的方式,对商场冬季室内热舒适性进行了调查研究,并对调查测试结果进行了统计回归分析。研究结果显示:商场冬季室内实测热中性温度为19.4℃,90%满意度热舒适温度范围为16.1~22.7℃;而根据PMV计算得到的室内热中性温度为16.8℃,90%满意度热舒适温度范围为13.3~20.4℃;PMV模型预测的热感觉比现场问卷调查得到的平均热感觉MTS要高,与实际感觉存在一定偏差。基于实测热舒适数据,进一步分析了室内热中性温度与室外空气温度的相关性,确立了商场冬季室内热中性温度与室外空气温度的近似线性关系,建立了商场冬季室内热舒适气候适应性模型。     

Occupants’ impact on indoor thermal comfort: a co-simulation study on stochastic control of solar shades

This paper investigates the impact of manually operated solar shades on indoor thermal comfort. A developed stochastic model for manual solar shades was modelled in Building Controls Virtual Test Bed, which was coupled with EnergyPlus for co-simulation. Movable solar shades were compared with two unshaded windows (clear double-pane and low-e double-pane). Two objective indices (room base temperature and transmitted solar radiation) and one subjective index (modified predicted mean vote (PMV) index (PMVrad) that considers solar radiation on the human body) were used to evaluate the indoor thermal performance. Results show that external solar shades achieve the best performance in terms of all three indices, especially for PMVrad, hours of comfortable conditions are higher than unshaded windows by 20.6–37.3%. Despite achieving relatively high performance, solar shades are operated infrequently and for about 30% of work time they are not adjusted appropriately, leading to a decrease in indoor thermal comfort.     

The impact of immigration on housing prices in Australia

In recent years, Australia has experienced high rates of immigration. We investigate the effect that this has had on housing prices at the postcode level. The endogeneity of immigrant inflows is accounted for using the Bartik shift-share approach. Using data from the censuses in 2006, 2011, and 2016, we find that an immigrant inflow of 1% of a postcode's population raises housing prices by around 0.9% per year. As a result, Australian housing prices would have been around 1.1% lower per annum had there been no immigration. The size of this effect is broadly consistent with that found for other countries. The effects of immigration on housing prices were larger in the more recent part of the period examined and strongest in the states of New South Wales and Victoria, and the cities of Melbourne and Adelaide. Chinese and Indian immigrant groups are shown to have a strong positive influence on prices.     

我国湿热地区人群基础热舒适反应研究(2):研究结果的对比分析

基于我国湿热地区人群的气候室实验结果,从心理热反应、生理热反应和生理-心理关系等多方面对国内外研究结果进行了系统对比与分析,发现现行国际标准不适用于我国湿热地区,生理热习服和心理热适应是其重要原因。考虑热习服和热适应的影响作用,建立我国湿热地区人群的生理热调节模型与心理-生理模型,是掌握其基础热舒适反应规律、合理制定热环境标准的重要途径。     

The impact of transit-oriented development on housing prices in San Diego, CA

This research measures the influence of transit-oriented development (TOD) on the San Diego, CA, condominium market. Many view TOD as a key element in creating a less auto dependent and more sustainable transport system. Price premiums indicate a potential for a market-driven expansion of TOD inventory. A hedonic price model is estimated to isolate statistically the effect of TOD. This includes interaction terms between station distance and various measures of pedestrian orientation. The resulting model shows that station proximity has a significantly stronger impact when coupled with a pedestrian-oriented environment. Conversely, station area condominiums in more auto-oriented environments may sell at a discount. This indicates that TOD has a synergistic value greater than the sum of its parts. It also implies a healthy demand for more TOD housing in San Diego.     

Influence of practical curing methods on evaporation of water from freshly placed concrete in hot climates

The effectiveness of different curing methods on the evaporation of water from freshly placed concrete is presented. The curing methods employed within the current experimental programme comprised plastic sheeting and burlap and were compared to the evaporation of water from an uncovered concrete surface. Samples were exposed to an ambient temperature of 40°C and a relative humidity of approximately 30% for a period of 72 h. The effectiveness of each curing method was quantified in terms of both the cumulative water loss and rate of evaporation from the concrete surface. When compared to the uncovered surface, both curing systems resulted in a reduction in both the total amount of water loss and rate of evaporation, particularly over the initial 6 h after mixing. A local maximum in the rate of evaporation coincided with the maximum in internal temperature occurring within the concrete, the latter being due to setting of the cement binder.