Study On The Evaluation Method Of Building External Sunshade Based On Building Comprehensive Performance Analysis

External sunshade system can create enormous building energy efficiency benefits at low cost.It has many effects on the building.Objectively speaking,it affects the annual energy consumption,indoor natural lighting,and indoor ventilation.While from a subjective perspective,external sunshade system affects the indoor thermal comfort,visual comfort and ventilation comfort.How to find a balance between building energy efficiency and indoor comfort is worthy of in-depth study.This article will comprehensively evaluate the impact of external sunshade system on the building’s energy consumption,indoor thermal environment,indoor natural lighting environment,indoor ventilation environment and view visibility from a comprehensive perspective,and establish an evaluation of the comprehensive performance of external sunshade system.Office building in Nanjing is taken as an example to study the evaluation system of the comprehensive performance of external sunshade.Firstly,spot investigation is used to collect external sunshade data of office buildings in three typical office areas in Nanjing and then representative external sunshade system of office buildings is sorted out based on the data.Secondly,the weight of each element in the comprehensive shading performance evaluation system is determined according to the questionnaires of the performance of external sunshade system that given out to experts and office users.The weight of Indoor light environment,Indoor air environment,Indoor thermal environment,Building energy and Line of sight is 0.243、0.221、0.268、0.107、0.161 respectively.Thirdly,APMV,UDI,Age of air,View rate and Heating and cooling consumption are selected ftom the existing evaluation indexes of each element to qualitatively evaluate the influence degree of external sunshade system on each element of the building.Five score tables for each element are developed.After determining the weights and evaluation indexes of all elements,a comprehensive performance evaluation system for external sunshade is established.Finally,the selected representative external sunshade system of the office buildings are used to verify the comprehensive performance evaluation system of the external sunshade system.Architectural design is a work that comprehensively considers multiple issues and balances multiple factors.As an important part of the building,external sunshade system should also be comprehensively analyzed.The research results of this thesis help designers evaluate external sunshade system from the comprehensive perspective when designing and selecting external sunshade system,and find a balance between energy consumption and indoor comfort according to user demands in order to promote building energy efficiency integrated design.