Research On Energy Saving Performance And Carbon Emissions Of Lightweight Wooden Structures

Under the background of continuous urbanization in China,the construction industry is developing rapidly.With the continuous increase in the output of China's housing construction and the promotion of the concept of energy conservation and environmental protection in the construction industry,low-carbon buildings have gradually attracted public attention.In recent years,researchers in China have started to study energy-saving performance and carbon emissions in first-tier cities such as Beijing,but there are few studies in third and fourth tier cities,where dramatic urbanization also occurs.This study first measured the heat transfer coefficient of the exterior wall and roof wall based on a wooden building design drawing in Qiandongnan of Guizhou province,and calculated the thermal insulation performance.Then,the node heat transfer coefficient was calculated according to the node structure The energy consumption of buildings in wooden structures and concrete buildings with the same structure was calculated.Finally,the research calculates the carbon emissions of the two structural buildings during the operation phase.The main conclusions are as follows(1)The heat transfer coefficient of the lightweight wooden structure of the roof structure and the outer wall is 0.42 W/(m2·K)and 0.81 W/(m2·K)respectively.The thermal coefficient is too large and the effect of heat insulation is insufficient which is compared with the wall of the standard light wooden building.From the perspective of the structure of the two walls,the thickness of the wall is small.According to the design drawings,the thickness of the insulation cotton is smaller than the cavity of the wooden keel.Therefore,the insulation wool does not completely fill the wood keel during the test and the wall heat transfer coefficient is too large.(2)This study analyzes the heat transfer coefficient of the structural nodes of light-weight wood structures and concrete structures.The four structural nodes of the light-weight wood structure are a floor slab,a wall and a two-story slab,a roof and an inner wall,and the upper and lower left and right ports of a window.The heat transfer coefficients were 0.03 W/(m2 ·K),0.02 W/(m2·K),0.03 W/(m2·K)and 0.14 W/(m2·K),respectively.The heat transfer coefficients of the four nodes of the concrete structure were 0.08 W/(m2·K),0.05 W/(m2·K),0.04 W/(m2·K),0.27 W/(m2·K),the heat transfer coefficient of the light-weight wooden structures is obviously lower than that of the concrete structures,which indicates the insulation of the structures of the light-weight wood structures is better than concrete structure construction.(3)This study simulates heating and air conditioning loads for two structural buildings using the Designer's Simulation Toolkit(DeST).The annual cumulative cold and heat load index of light-weight wooden buildings and the annual power consumption of heating and air-conditioning were 2.37 kW·h/m2,44.20 kW·h/m2 and 24.29 kW·h/m2,respectively,and the annual cumulative cold and heat load indicators and heating and air conditioning annual power consumption were 7.47 kW·h/m2,52.44 kW·h/m2 and 30.85 kW·h/m2,respectively.Lightweight wood-frame buildings are 21.25%more energy-efficient than concrete structures.(4)This study analyzed the carbon emissions of the two types of buildings in the operation and maintenance phase.The light-weight wood-frame construction was 823.97 tCO2,and the concrete-construction building was 986.43 tCO2.Overall,the carbon-emissions of the concrete-construction buildings was 20%lower than that of the light-wood-structures during the operation phase.