Life Cycle Primary Energy Use in Buildings of High Energy Standards

摘要

In this study, we examine the life cycle primary energy use of buildings. Our analysisrnstarts with a conventional timber-frame building. We maintain the architectural design, but alterrnthe thermal properties of the envelope components and include heat recovery of ventilation air tornachieve buildings with similar thermal properties as three existing passive house in Sweden. Wernalso vary the building frame material from timber to concrete, and the heat supply systemrnbetween district heating and electric resistance heating. We then follow the life cycle of thernbuildings, analyze and compare their life cycle primary energy use, including the production,rnoperation and end-of-life energy uses. The results show that the life cycle primary energy use ofrna passive house building is substantially lower when it is constructed with a timber instead of arnconcrete frame and heated with district heating instead of electricity. A passive house withrnelectric heating does not achieve lower primary energy use than a conventional house withrndistrict heating. Material production accounts for a relatively large share of the life cycle primaryrnenergy use in passive standard buildings, and is proportionally more significant if the heat supplyrnis from district heating. Material choice is thus relatively more important as buildings becomernmore energy efficient and energy-efficient heat supply systems are used.