Influence Of Green Space On Thermal Environmental Characteristics Outside The Building And The Human Comfort

With the growing urban population, the developing process of the city and the converting urban surface, urban thermal environment has changed. Building exterior urban environment is the most frequently used sites, so looking for ways to improve the thermal environment outside the building has become the focus of recent research. Buildings’ Thermal Environmental Characteristics include a number of related factors, such as temperature, humidity, wind and the mean radiation temperature. Changes in these factors depend not only on the buildings’ morphology, structure and material, but also closely related to the composition of the underlying surface of the surrounding buildings. Green space as the important underlying surface, It can also improve the thermal environment have a good effect. Human comfort is used to evaluate the thermal environment comfort level indicator. At present, to improve the effect of the relationship between building thermal environment, green and human comfort, as well as green space in different environmental scales on improving thermal comfort effect is still no clear answer. Therefore, by field measurements and software analysis, discuss the impact of different scales in Greenbelt features and layout of the building exterior thermal environment characteristics and human comfort. It can provide a strong basis for urban green space planning and design.The main contents and conclusions are as follows:1. In the micro scale:Peking University Healthcare Industrial Park(PUHIP) is an object of this study, This experiment is designed to study the impact between different architectural space, changes in the external environment and increase green areas of the park heat environment and human comfort.(1)Characteristics of the thermal environment and human comfort within the PUHIP affected by architectural space. In all seasons have shown the temperature on the south side space of building is greater than the north side of the building space.(2) Characteristics of the thermal environment inside the PUHIP may be affected by the external environment. The research studied the small park located in the southeast of the PUHIP, and its impact on the surrounding environmental thermal features. (The park in October of external environment have a more significant cooling humidification role, and in February the external environment have a more significant role in the insulation), The results showed that, although the characteristics of the thermal environment surrounding the park will have an impact, but the PUHIP’s thermal environment more depends on the internal total amount of green space and the building structure inside of the PUHIP. (3) With the increase of vegetation, the PUHIP gradually showing a cooling trend and achieve maximum cooling during the summer months was 2.65%. The humidity outside the PUHIP is higher than the inside humidity, And with the increase of vegetation, the PUHIP’s humidification rate also increased, up to 12.15%. Discomfort index of the park with a maximum reduction rate of 5.85% in the summer, indicating that the increase of the park’s vegetation can reduce the discomfort index of the PUHIP to a certain extent. This shows an increase vegetation within the PUHIP can reduce the discomfort index of the park to a certain extent.2.In the block scales:Taking Beijing Forestry University, Beijing University of Technology, Beijing University of Aeronautics and Astronautics and the North Pole Temple retired cadres as samples, the relationship between the composition of the underlying surface characteristics of the thermal environment and human comfort range of different blocks were studied. (1) Through correlation and regression analysis, a variety of factors have been found to affect the environment of measuring points in the summer high temperature period. Air temperature increases with increasing the impervious surface coverage but decreases with increasing of vegetation coverage while air humidity showed the contrary characteristics. Through the study of vegetation coverage cooling and humidification effect on 20m and 50m scales, we found that the effect of plant cooling and humidification in 20m scale was more significant. In the spring of 2016, daily changes of thermal environment characteristics were observed in Beijing Forestry University. This study revealed that the relationship between air temperature and the building coverage from 10:00 am to 14:00 pm, negatively correlated, at 16:00 began to turn positive correlation, but the correlation was not obvious in the evening, which may be related to the sunset. (2) Under conditions of meeting the green land rate and the block building coverage rate were similar, this study also examined three different arrangements of neighborhoods, which including Beijing University of Technology (decentralized), Beijing University of Aeronautics and Astronautics (centralized), the Arctic Temple (centralized distributed), and found that centralized and decentralized greenbelt has better cooling and humidifying ratio and higher comfort level. (3) This layout of the green space not only set more green area in the block, but also dispersed in the various regions of the surrounding buildings which can ensure a high green coverage, so it can be maximum more regions with lower temperature and higher humidity.3. At local scales:In this study, Olympic Forest Park (OFP) and three settlements in its eastern part were taken as samples, the city park and its impact on neighboring settlements thermal environment characteristics and indicators of human comfort were explored. (1) It was found that in the high temperature period, OFP has a certain humidification cooling efficiency to its surrounding environment, with the maximum cooling intensity was 2.88℃, and the maximum intensity of humidified was 7.93%. Further, with respect to the external environment of the park, it has a certain OFP reduce discomfort index characteristics. (2) Closer to the park, the community has a lower temperature, higher humidity and a lower degree of discomfort index. Within the scope of OFP around 2000m, Each 500m from OFP, live zone temperature increases 0.85 degrees, humidity is reduced by 1.5%. Not comfortable degree index increases 0.4.The Experimental Study the influence of Green Space to external of Buildings’ Thermal Environmental Characteristics and Thermal Comfort in different scale. It can provide a theoretical basis for ecological, comfortable environment outside the building in green design, and planning guidance Beijing settlements on human comfort levels.