دانلود رایگان مقاله هزینه و اثربخشی عایق حرارتی سیستم سقف سبز

Abstract

Hong Kong is a densely populated city with high density of skyscrapers and the population is typically concentrated on 30% of the land. The adoption of skyscrapers is therefore common to maximize its capacity. As a result, the need of open space and greenery in our built environment is thus often neglected. In recent years, many building professionals promote green-roof systems to increase green space. This paper investigates the effectiveness of using green-roof systems. Questionnaire surveys and interview discussions are conducted. It is found that the questionnaire respondents are interested in implementing green-roof systems and understanding their environmental, economical and social benefits. Three case studies are also conducted to show the effectiveness of green roofs thermal insulation. The results show that green roofs can reduce the inside temperature by up to 3.4
C. However, the respondents were not willing to invest a large amount of money for green-roof systems. It is suggested that governments should take leading positions to promote green-roof systems. This paper can provide insights on the use of green roofs in Hong Kong and around the world focusing on cost effectiveness and thermal insulation effectiveness.

6. Conclusion

This paper has examined thermal insulation and cost effectiveness of using green-roof systems in Hong Kong. Questionnaire surveys and interview discussions were conducted. It has been found that green-roof applications are not widely adopted in Hong Kong. Improve visual aesthetic value of the building is the major benefits gained on the green-roof implementation. From the implementation of green-roof systems, air quality can be improved and urban heat-island effect can be reduced. However, the respondents are not willing to invest for implementing green-roof systems. It was suggested that government should takes the leading position for the promotion of green-roof systems together with other stakeholders. The three case studies also proved that greenroof systems can improve thermal insulation by up to 3.4
C. The results revealed that soil depth and plant types are particularly significant to the thermal insulation performance. The deeper soil may have a higher efficiency in moisture retention and lead to a higher evaporation efficiency from the plants that leads a higher thermal insulation performance. It was revealed that the capital costs spend on the green roof proportionally enhance the performance of thermal insulation. The calculated thermal insulation effectiveness for the case studies is found to be similar. This can be explained with the geological conditions in Hong Kong with mostly moisture of around 95% humidity level for the whole year. This can enhance plant development and its thermal insulation effectiveness on the green-roof systems.