Study On Building Envelope Energy-saving Retrofit And HVAC System With Life Cycle Assessment Method

With the development of economic and real-estate industry, the proportion of building energy consumption in total energy consumption is in sustained growth. At the same time, the environmental impact is increasingly prominent caused by great consumption of energy and resources. So it's necessary and important to take actions on energy saving. In this case, more energy efficiency can be achieved by less input of resources and money.Life Cycle Assessment Method started from the last 90's and then was developed and applied in many fields in most Europe and North America, such as the industry production life cycle assessment, the evaluation to environment management, the life cycle analysis in architecture areas and so Based on the theoretical study of the life cycle, life cycle assessment is carried out from both the building envelope and equipment systems in this article, which is quiet different from the past life-cycle analysis. The building envelope part of the life-cycle assessment includes building materials production stage, the construction phase of the envelope structure, daily use stage, the removal of envelope phase and the recycle stage of the waste building materials. The equipment system life cycle assessment includes the equipment material production stage, the operation stage as well as the waste equipment materials recycling stage. Both parts consist of the evaluation to energy consumption and environmental impact.Since the present evaluation to building energy consumption is for the building using stage or the device operating stage, the evaluation is of one-sidedness to some extent. Against this background, this article studies the energy consumption from the point view of life cycle assessment method on both the building envelope and the devices in a more systematic and comprehensive way. The standards, which are used to determine the feasibility of the energy-saving program with the method of life cycle analysis, are put forward in this paper. That is to say, if the device consumption reduced by energy-saving transformation is greater or much greater than the life cycle cost of investment to building envelope or equipment, the transformation is meaningful. Through the method of life cycle analysis used to evaluate building energy-saving transformation, the potential energy consumption of building materials are noticed gradually by people. And finally, the residential building in Ningbo is used as a typical case to illustrate the life cycle analysis. The idea of total life energy saving put forward in this article plays an important role to energy efficiency of building material industry, energy-efficient building design, transport energy saving, recycle of waste materials and reduction of environmental emissions.