Improvement Of Thermal Environment Research Articles

Study on urban thermal environmental factors in a water network area based on CFD simulation

Abstract Cities on the Jianghan plain with a dense water network have a hot and humid climate and a long period of calm wind in the summer. Urban design guidance of a water network with a thermal environment as the starting point is a design control path that takes into account geographical features, climatic conditions and urban construction under complex constraints. Based on the current block division and development intensity, this study of the thermal environment of Xiantao adopts the methods of multiple linear regression and wind–thermal environment simulation. The results show that regional agglomeration shows the spatial distribution of the urban thermal environment in the water network area. The distribution of hot sensitive areas is closely related to the pattern of clusters. The business district, high-density urban area, basic energy facility area and transportation hub are the thermal environment areas. The experimental results show that residential and industrial land, proportion of water area, average elevation and urban development intensity are the main factors influencing the thermal environment of the water network, and the strengths of their effects are in the order of development intensity > water area proportion > industrial land proportion > residential land proportion > average elevation. The urban thermal environment of the dynamic construction area can be inferred. The improvement of urban wind and thermal environment quality is implemented in the urban space level by guiding the construction intensity, ventilation, greening and water, and paving and shading of the thermal environment control area. The exploration of the thermal environment improvement method in the urban design of a water network region provides the guidance for similar cities seeking to cope with climate change.

Measurement and Analysis of the Thermal Insulation Effect of the Transition Space of a Building Veranda in the Hot Summer and Cold Winter Zone

The thermal environment of a building plays a direct role in the energy consumption of the building. Veranda, considered as a common element of a building in a hot summer and very cold zone, connects indoor and outdoor spaces and provides a transitional space for the building. It has certain influences on the thermal environment of the use space. In this paper, a veranda on the east side of a building in Wuhan, China is taken as the research subject, and the thermal data of indoor and outdoor settings are collected through a network of field sensors. The thermal characteristics of the transitional space are then studied, and the thermal insulation effects of the veranda is comprehensively investigated. The statistical results show that the veranda has a good thermal insulation effect in summer, and the reasonable design of transitional space is instrumental to the improvement of thermal environment and the reduction of building energy consumption.

Occupants’ Responses to Naturally Ventilated Buildings in Northern Guizhou, China

With the acceleration of urbanization, suggestions that are based on findings gathering from field studies on building refurbishment, new building design and building operation and maitenance are essential to achieve building energy saving and carbon emmision target. Therefore, a field investigation on thermal comfort and adaptive responses of occupants in naturally ventilated buildings were conducted during winer time in Zunyi. Without central heating system supply, the mean value of indoor air temperature is 14.86°C. But more than half of occupants (57.9%) who were satisfied with surrounding thermal environment. People are active to utilize various strategies to restore thermal comfort of their own. Adjusting clothing levels and using heating devices (e.g. fan heater, portable hand warmer, etc.) are the most popular adaptive behaviours helping them alleviate thermal discomfort caused by lower and humid thermal environment. The aPMV model is developed with adaptive coefficient of -0.33. The findings obtained from this investigation fill gaps in similar researches in northern Guizhou and provide guidelines on building indoor thermal environment improvement considering passive design strategies in this area.

식재설계 및 시공을 통한 공동주택 외부공간의 하절기 열환경 개선

2018년 여름의 폭염은 기상관측을 시작(1907년 10월 1일)한 이래 111년 만에 가장 높은 기온을 기록하였는데, 서울은 39.6℃를 기록(2018년 8월 1일)하여 종전의 기록인 38.4℃(1994년 7월 24일)를 뛰어넘었다. 열섬현상으로 인해 도시의 온도가 상승하고 하절기 열쾌적성이 저하됨에 따라 하절기 열환경 개선에 대한 연구가 지속적으로 진행되고 있다. 본 연구의 목적은 조경공 사 전·후의 온도저감 및 외부공간 이용자가 느끼는 열환경 개선에 대하여 정량적으로 검증하여 설계 및 시공단계에서 활용할 수 있는 기초적 자료를 제공하고자 하였다. 연구결과는 다음 과 같다. 미기후 실측에 의한 측점별 조경공사 전·후의 온도저감을 비교 분석한 결과, 오전 10 시 조경공사 전 평균온도는 34.5℃이며, 조경공사 후 평균온도는 32.5℃로 2.0℃온도저감 효과가 있는 것으로 분석되었으며, 오후 2시 조경공사 전 평균온도는 37.5℃이며, 조경공사 후 평균 온도는 35.9℃로 1.6℃ 온도저감 효과가 있는 것으로 분석되었다. 오후 5시 조경공사 전 평균온 도는 33.8℃이며, 조경공사 후 평균온도는 31.2℃로 2.6℃ 온도저감 효과가 있는 것으로 분석되었다. 연구결과의 활용방안으로 정량적인 연구방법과 결과는 디자이너의 직관적인 조경설계에 객관성을 부여하는 기초자료로서 활용이 가능할 것이다.

Thermal comfort and energy-saving potential in university classrooms during the heating season

A classroom thermal environment directly not only influences students’ thermal comfort but also energy-saving. Numerous studies indicate that students’ actual thermal comfort is different from the PMV and adaptive model predictions, and the current thermal comfort standards could not be applicable for the classroom thermal environment design and evaluation. This paper aims to study the university students’ general and local thermal comfort by a field survey conducted in a classroom during the heating season in Taiyuan, China. The results indicated that PMV overestimated the thermal sensation of students. Thermal acceptance vote (TAV) defined the widest acceptable temperature range, and the lower limit for 80% acceptability could be 19 ℃ in Taiyuan. Students preferred a cooler than a neutral environment. The indoor design temperature determined by the heating load duration curve (LDC) was about 21.85 ℃. If the indoor design temperature could decrease from 21.85 ℃ to 19 ℃, 3.46% of the annual heating load could be saved. Moreover, although a majority of students found the environment general thermal acceptable, a higher percentage of students felt local thermal discomfort. Local thermal comfort should be a critical issue for the classrooms’ thermal environment improvement.

Developing the Urban Thermal Environment Management and Planning (UTEMP) System to Support Urban Planning and Design

Mathematical Climate Simulation Modeling (MCSM) has the advantage of not only investigating the urban heat island phenomenon but also of identifying the effects of thermal environment improvement plans in detail. As a result, MCSM has been applied worldwide as a scientific tool to analyze urban thermal environment problems. However, the meteorological models developed thus far have been insufficient in terms of their direct application to the urban planning and design fields due to the preprocessing task for modeling operations and the excessive time required. By combining meteorological modeling and Geographic Information System (GIS) analysis methods, this study developed the Urban Thermal Environment Management and Planning (UTEMP) system that is user-friendly and can be applied to urban planning and design. Furthermore, the usefulness of UTEMP was investigated in this study by application to areas where the heat island phenomenon occurs frequently: Seoul, Korea. The accuracy of the UTEMP system was verified by comparing its results to the Automatic Weather Systems (AWSs) data. Urban spatial change scenarios were prepared and air temperature variations according to such changes were compared. Subsequently, the urban spatial change scenarios were distinguished by four cases, including the existing condition (before the development), applications of the thermal environment measures to the existing condition, allowable future urban development (the maximum development density under the urban planning regulations), and application of the thermal environment measures to allowable future development. The UTEMP system demonstrated an accuracy of adj. R2 0.952 and a ±0.91 Root Mean Square Error (RMSE). By applying the UTEMP system to urban spatial change scenarios, the average air temperature of 0.35 °C and maximum air temperature of 1.27 °C were found to rise when the maximum development density was achieved. Meanwhile, the air temperature reduction effect of rooftop greening was identified by an average of 0.12 °C with a maximum of 0.45 °C. Thus, the development of UTEMPS can be utilized as an effective tool to analyze the impacts of urban spatial changes and for planning and design. As a result, the UTEMP system will allow for more efficient and practical establishment of measures to improve the urban thermal environment.

A field research on the impact of underlying surface configuration on street thermal environment in Lhasa

Commercial street is an important place for outdoor activities of urban residents. The quality of its thermal environment directly affects the comfort of pedestrians and the energy consumption of surrounding buildings. Block-scale microclimate studies have already been conducted in the context of different climates, while limited attention has been paid to the microclimate within high-altitude cold climate. Tibet, as the main body of the Qinghai-Tibet Plateau, presents typical plateau climate characteristics, and its unique natural climate conditions will certainly give birth to special urban environmental problems. Therefore, taking Lhasa as an example, this paper focuses on the impact of street thermal environment under different underlying surface configurations under unique plateau climate conditions. Based on the field measurement of the thermal environment of three streets in Lhasa City, namely, Yutuo Road, Duosen Road and Hongqi Road, the influence of different underlying surface design elements, namely, greening and water area, on the near ground microclimate and pedestrian comfort of the streets were analyzed. The analysis results of the measured datas show that: there are obvious temperature differences in the streets of different directions. Trees have a more significant cooling effect on East-West streets. The leaf area index (LAI) of trees will affect the improvement of thermal environment. Fountain has cooling effect in summer, but it is lower than that of trees. The research contents of this paper provides data basis for further research on the thermal environment and the optimization design of the underlying surface of the streets in the high altitude cold climate area.

非住宅建築物を対象とした先導的省エネルギー技術の評価方法に関する研究 その5 各種窓仕様の温熱環境改善と熱負荷低減効果に関する研究

非住宅建築物を対象とした先導的省エネルギー技術の評価方法に関する研究 その5 各種窓仕様の温熱環境改善と熱負荷低減効果に関する研究

Percentage Coverage of Tropical Climbing Plants of Green Facade

Green façade (GF) is one of vertical greenery systems used as passive solutions applied on building façade in improving indoor thermal environment and energy efficiency. However, optimum improvement of thermal environment from GF is dependent on the overall foliage coverage established on the system itself. Higher percentage coverage of the foliage is expected to regulate and lessen the heat transfer toward inside environment. Therefore, this study is to investigate the potential of selected tropical climbing plants in establishing foliage coverage on the GF. Three selected tropical species of climbers used on green façade; i.e. Anemopaegma chamberlaynii (AC), Antigonon leptopus (AL), and Quisqualis indica (QI). A small-scale experiment with small scale size of freestanding walls (1.5 m (height) × 1.0 m (width) × 0.15 m (thick)) attached with GFs (modular trellis) and planter boxes at ground were built for this study. Despite small size leaf, AC performed consistently and has the highest percentage coverage throughout the measurement period with average of 86.5 %. The dominant trait of AC which is vigorous and fast growth rate contributed to the dense and almost fully covered the trellis structure of green façade. Higher percentage coverage also estimated to generate an instantaneous effect on thermal environment modification.

CFD 시뮬레이션을 이용한 시설원예단지 여름철 외부 열환경 특성 및 개선방안

CFD 시뮬레이션을 이용한 시설원예단지 여름철 외부 열환경 특성 및 개선방안

Investigation on thermal environment improvement by waste heat recovery in the underground station in Qingdao metro

The thermal environment parameters, like the temperature and air velocity, are measured to investigate the heat comfort status of metro staff working area in winter in Qingdao. The temperature is affected obviously by the piston wind from the train and waiting hall in the lower Hall, and the temperature is not satisfied with the least heat comfort temperature of 16 °C. At the same time, the heat produced by the electrical and control equipments is brought by the cooling air to atmosphere for the equipment safety. Utilizing the water-circulating heat pump, it is feasible to transfer the emission heat to the staff working area to improve the thermal environment. Analyzed the feasibility from the technique and economy when using the heat pump, the water-circulating heat pump could be the best way to realize the waste heat recovery and to help the heat comfort of staff working area in winter in the underground metro station in north China.

非空調の大空間作業室の改修による熱環境改善効果に関する研究 （その3) 改修概要及び冬期の熱環境改善効果

非空調の大空間作業室の改修による熱環境改善効果に関する研究 （その3) 改修概要及び冬期の熱環境改善効果

非空調の大空間作業室の改修による熱環境改善効果に関する研究 (その4)天窓・シーリングファン利用が冬期の室内熱・空気環境に及ぼす影響

非空調の大空間作業室の改修による熱環境改善効果に関する研究 (その4)天窓・シーリングファン利用が冬期の室内熱・空気環境に及ぼす影響

Indoor thermal environments in Chinese residential buildings responding to the diversity of climates

China has a diversity of climates and a unique historic national heating policy which greatly affects indoor thermal environment and the occupants’ thermal response. This paper quantitatively analyzes the data from a large-scale field study across the country conducted from 2008 to 2011 in residential buildings. The study covers nine typical cities located in the five climate zones including Severe Cold (SC), Cold (C), Hot Summer and Cold Winter (HSCW), Hot Summer and Warm Winter (HSWW) and Mild (M) zones. It is revealed that there exists a large regional discrepancy in indoor thermal environment, the worst performing region being the HSCW zone. Human’s long-term climate adaptation leads to wider range of acceptable thermal comfort temperature. Different graphic comfort zones with acceptable range of temperature and humidity for the five climate zones are obtained using the adaptive Predictive Mean Vote (aPMV) model. The results show that occupants living in the poorer thermal environments in the HSCW and HSWW zones are more adaptive and tolerant to poor indoor conditions than those living in the north part of China where central heating systems are in use. It is therefore recommended to develop regional evaluation standards of thermal environments responding to climate characteristics as well as local occupants’ acclimatization and adaptation in order to meeting dual targets of energy conservation and indoor thermal environment improvement.

トラックキャビンに対するダブルスキン技術の適用 : 第1報-炎天下駐車時に通気層を用いた二重天井システムの温熱環境改善効果の数値的検討

トラックキャビンに対するダブルスキン技術の適用 : 第1報-炎天下駐車時に通気層を用いた二重天井システムの温熱環境改善効果の数値的検討

A-21 非空調の大空間作業室の改修による熱環境改善効果に関する研究 : (その1)改修概要及び夏期の熱環境改善効果

A-21 非空調の大空間作業室の改修による熱環境改善効果に関する研究 : (その1)改修概要及び夏期の熱環境改善効果

A-22 非空調の大空間作業室の改修による熱環境改善効果に関する研究 : (その2)天窓・シーリングファン利用が室内熱環境に及ぼす影響

A-22 非空調の大空間作業室の改修による熱環境改善効果に関する研究 : (その2)天窓・シーリングファン利用が室内熱環境に及ぼす影響

C-65 水まわり空間を中心とした省エネルギー性と快適性に関する研究 : (第6報)浴室まわりの温熱環境改善に伴う湯消費-温熱感・身体ストレスの検討

C-65 水まわり空間を中心とした省エネルギー性と快適性に関する研究 : (第6報)浴室まわりの温熱環境改善に伴う湯消費-温熱感・身体ストレスの検討

生活スタイルの変化による住宅におけるエネルギー削減効果の研究 （第５報）室内温熱環境改善効果の検証

生活スタイルの変化による住宅におけるエネルギー削減効果の研究 （第５報）室内温熱環境改善効果の検証

Experiment Research on Shading to Improve the Thermal Environment of Tents

Different black agricultural shading-nets were erected on two 93 type military cotton tents to improve the thermal environment of tents in this paper. Indoor temperature, RH (relative air humidity) and interior wall temperature were tested. The experimental results show that shading-nets a effect on the improvement of thermal environment and 6 needled filters shading-net is better than 3 needled filters shading-net. The conclusion of this paper provides a basis for the improvement of the thermal environment and energy saving design of the tent.