| The top floor of the assembled residence is not only the key link of the overall energy saving index of the building,but also the location where the architectural form and space change the most.There are a lot of achievements on the improvement of the top thermal environment in the existing studies,but most of them focus on the improvement of the thermal performance of the roof,without considering the top energy saving from the perspective of the space and form of the top.Xining area is rich in solar energy resources,from the perspective of solar radiant heat utilization,the influence of energy saving design factors of top floor space,form and structure on top floor energy saving is studied,and the key points of energy saving construction technology are put forward,which is of great significance to reduce the top floor heating load of urban residential buildings in Xining.This paper takes the top floor of residential buildings in Xining,China as the research object.Firstly,the indoor thermal environment of the top floor of residential buildings is measured.The reasons for the poor indoor thermal environment of the top floor are analyzed as follows: poor thermal performance of the roof,energy saving is not considered in the slope of the roof,improper use of buffer space of the top floor,and insufficient use of solar radiation heat of the top floor.14 second collection of xining city residential housing construction current situation of research,to extract more than 18 layer residence,the top three typical physical model room door,retaining structure for the research status quo of the structure and 75% energy saving,using energy consumption simulation software Designbuilder simulation top space,energy efficiency design in the form of the influence of factors on the top floor heating load,The proposed value of energy saving design factors is given,and the concept of contribution rate of top level energy saving is put forward,which is used to compare the contribution of energy saving design factors to top level energy saving,and the order of the contribution rate of energy saving design factors to top level energy saving is given.In terms of structure,the insulation structure form and thickness of insulation materials of roof and exterior wall were studied,and the insulation materials and thickness of insulation materials and their structural nodes were suggested.Finally,based on the actual case of Country Garden,the paper applied various energy saving factors on the top floor.The contribution rate of energy saving on the top floor was45.51%,and the contribution rate of energy saving on the whole building was 9.77%.Main research results:Conclusion 1: The ranking of the energy saving contribution of the top floor is given by the energy saving design factors of three typical house types.Under the research structure,the energy saving contribution rate of the top floor is ranked as the ratio of south window and wall to > transparent slope > roof skylight to > opaque slope > balcony,and the energy saving contribution rate of the top floor is ranked as the ratio of south window and wall to > roof skylight to > transparent slope > opaque slope to > balcony.The contribution rate of energy saving of the local north south loft of the top floor is ranked as the proportion of roof skylight > south window and wall >transparent slope > opaque slope > balcony.Under the structure of 75% energy saving,the energy saving contribution rate of the three top floor typical apartment types is ranked as the ratio of south window and wall to > roof skylight ratio > transparent slope > opaque slope > balcony.Conclusion 2: Suggestions for energy saving design factors of top floor typical house types are given.(1)For the flat floor of the top floor,the depth of the balcony is recommended to be 0.9-1.5m and the opening ratio of the common wall interface is recommended to be 50% under the investigation of the current structure and 75%energy saving structure.For partial south jumping floor and partial south north jumping floor,the upper and lower height of the south facing balcony is more energy saving.Under the current research structure,the balcony depth is suggested to be0.9-2.1m,and the wall interface opening ratio is suggested to be 50%.Under the structure of 75% energy saving,the balcony depth is suggested to be 0.9-1.8m,and the wall interface opening ratio is suggested to be 50%-70%.(2)Considering the requirements of energy conservation and style,the slope of opaque roof is considered.The slope of roof of the top floor and partial north-south house type is ≤30°,and the slope of partial south-facing house type is ≤35°.When the roof is opened,the heating load of the top floor can be reduced.(3)Under the current structure and 75%energy saving structure,the skylight area ratio of the top floor is less than 50%,and the partial south loft of the top floor and the partial south north loft of the top floor are less than 60%.(4)Based on the current structure of the survey,it is suggested that the southward window-wall ratio of the typical house type on the top floor should be 0.6;Under the structure of 75% energy saving,it is suggested that the south window-wall ratio of the typical house on the top floor is 0.65.Conclusion 3: Disequilibrium insulation design is adopted for the exterior wall and roof of the top floor of the congregated residence,and the recommended value of insulation thickness and structural nodes are given.(1)Under the same insulation thickness,adding north wall insulation contributes the most to the top floor energy saving.When the external wall insulation material is rock wool,it is suggested that the insulation thickness of south wall should be ≤120mm,the insulation thickness of west wall(east)should be ≤140mm,and the insulation thickness of north wall should be ≤160mm.(2)For the insulation design of the north-south slope roof,increasing the insulation thickness of the north-north slope roof is more conducive to the energy saving of the top floor.It is suggested that the thickness of the insulation material of the roof is ≤160mm. |
