Research On Passive And Energy Saving Retrofit Design Of Existing Residential Buildings In Tianjin

With the increase of building energy consumption,low energy building has become a hot research area.Passive architecture is popularized gradually in the world because of its low energy consumption and good indoor thermal comfort.Passive house can greatly improve the building thermal insulation performance and air tightness through the excellent building envelope insulation performance to minimize the outer envelope heat loss and ventilation heat loss;through a variety of means to achieve the wet environment and comfortable indoor thermal environment and lighting of the passive house as much as possible,and to minimize dependence on combustion heating fossil fuel and refrigeration system or completely cancel the heating and cooling facilities.Through a variety of means to achieve the passive building,wet environment and comfortable indoor thermal environment and lighting as much as possible,to minimize dependence on fossil fuel burning heating and refrigeration system or completely cancel the heating and cooling facilities.In this paper,we focus the four step energy saving residential buildings and the reconstructive the passive house.Using software simulation analysis combined with field testing method,we calculated the four step energy saving residential building's load and the load of passive house in design phase and analyzed the superiority of passive house in energy saving compared with four step residential.So we used a variety of testing instruments to test the heat transfer coefficient of the envelope,air tightness of building structure and total heat exchange efficiency of fresh air heat recovery unit.We simulated and measured the indexes of passive architecture in actual operation stage according to passive house standard and put forward measures to improve the operation effect.The results show that after passive transformation,the load and energy consumption of the four step energy saving building are obviously reduced,the decline of energy consumption in winter is especially obvious: demand for heating decreased by 81.8% in winter,the maximum heat load was reduced by 76.1%,demand for refrigeration decreased by 48.9% in summer,the maximum cooling load was reduced by 52.3%.After the reconstruction of the building measured,it is found that the passive structure has not reached the design requirements in the heat transfer coefficient of the outer envelope and the building's tightness.And the operation energy consumption is obviously larger than design energy consumption and energy consumption of simulated calculation using measured data,the primary energy consumption can not meet the requirements of passive house in Germany.The first cause maybe that the object of this study is to reconstruct buildings,the defect is congenitally deficient compared with the new passive building.The second cause is the performance coefficient of air source heat pump is low in cold region in winter and the defrost phenomenon is serious.The third cause is there are so many visitors to passive house that the cold air invasion is greatly increased.