Integrated Energy Saving Retrofit Of SiO₂ Aerogel Mat/PCM For Residential Balcony In Cold Area And Carbon Emission Study

With the rapid development of the economy,environmental issues have become the focus of attention,and the construction industry,as the main sector of energy use and carbon emissions,is unstoppable in terms of energy saving and emission reduction.In China’s cold regions,the prolonged heating season is accompanied by high energy use and carbon emissions,which has a significant impact on the achievement of the region’s"Double Carbon"aim.At the same time,as people’s demand for indoor comfort increases,existing residential buildings can no longer meet the requirements of people for indoor thermal environment.Energy-saving renovation of existing residential buildings has become the main measure to solve the existing high indoor environmental requirements,low energy consumption and low carbon row.Balconies,as part of existing residential buildings,contribute significantly to energy dissipation due to their enormous glass area and low thermal inertia.The purpose of this paper is to renovate the transparent and opaque envelopes of balconies using energy-saving and environmentally friendly materials in order to achieve energy savings,reduce emissions,and improve interior comfort.To do this,it will combine the present research state of existing residential structures with the features of natural resources in Northeast China.At first,using field measurements and research,the existing multi-story residential structures’inside thermal environment is examined.Using the preliminary measurement data,a model of existing multi-story residential buildings is created,and the model is validated as well as an analysis of the inside thermal environment is done.Second,energy-saving materials like phase change materials and silica aerogel mats are used to retrofit the balcony envelope of existing multi-story residential buildings in order to improve the thermal insulation and heat storage capacity of balconies.Their energy-saving optimization is then carried out to obtain the best retrofitting scheme.Also,a thorough analysis of the effects of building energy consumption and thermal environment before and after retrofitting is performed by applying the optimal retrofitting strategy to the existing multi-story residential balcony envelope.Finally,the building’s total life-cycle carbon emissions are computed based on three factors:the manufacture of building materials,transportation,and building operation,and the retrofit’s impact on carbon reduction is described.The details of the study are as follows:1.The residence type for the following study was chosen based on the present internal thermal environment of the existing multi-story residential structures in the Daqing region,which was examined by both questionnaire survey and field measurement.It is determined that the current multi-story residential structures in the extremely cold location have poor winter balcony temperatures and are unable to satisfy people’s needs for inside comfort.2.Based on preliminary measurement data,a model of an existing multi-story residential building is created,and the model is then verified using data from measurements of the inside thermal environment to select simulation software.3.To complete the thermal insulation and thermal storage transformation of the opaque balcony envelope of existing multi-story residential buildings,and to optimize the energy savings from the type of insulation material,the type of phase change material,and the thickness of phase change material in order to ultimately determine the best transformation plan.When the phase change material is made of 10mm thick C₁₆H₃₄ paraffin and foamed cement is used as the insulation,the best energy-saving results are obtained.4.Create energy-saving windows using Si O₂ aerogel felt to update the transparent envelope,compare and analyze the impacts of various thicknesses of Si O₂aerogel felt,glass,and air layer on building energy consumption,and choose the final design of energy-saving windows.The best energy saving benefit is attained when the thickness of silica aerogel mat,glass and air layer are all 6mm.5.The existing multi-story residential balconies that are subject to the balcony envelope retrofitting program have their energy consumption and indoor thermal environment impacts compared to before the retrofit,with the results showing a significant improvement after the retrofit.6.The whole building carbon emissions before and after renovation of existing multi-story residential balconies were determined using the three stages of building materials manufacture,transportation,and building operation,as well as the overall building life-cycle carbon emissions before and after restoration.The total building life-cycle carbon emissions were decreased by 105.775t CO₂e due to the balcony envelope improvement.