Life Cycle Assessment Of External Wall Insulation In Different Climate Zone

Based on the whole life cycle energy consumption and environmental emissionscalculation model, an analysis has been carried out for the energy consumption andenvironmental emissions of external wall insulation in its life cycle. The EnergyPlus hasbeen used for modeling an office building with two types of external wall insulation. Theglass wool and polystyrene foam board are chosen as the insulation materials. The energyperformance of external insulation wall in different cities---Harbin，Lanzhou，Wuhan，Kunming，and Guangzhou，has been calculated in EnergyPlus。These cities were selectedto represent the five main architectural climates—severe cold,cold, hot summer and coldwinter, mild, and hot summer and warm winter. Then the energy performance of wallwithout external insulation is treated as the reference，the purpose is to explore the benefitof energy efficiency in different insulation cases and in different climate areas. Thus,combine with the energy consumption of the insulation materials in its life cycle, theobjective of this study is to examine whether these insulation measures are feasible orenergy benefit.Combined with economic analysis at the same time，the whole life cycle investmentof wall insulation was calculated，the aim of economic analysis is to compare economicbenefit of energy efficiency with the wall insulation investment，and study the feasibilityof investment.The results show that the external wall insulation can effectively reduce the energyconsumption of wall heat transfer. However, if the service life of building external wallinsulation is assumed to be20years，in consideration of the environment impact of thewhole life cycle of wall insulation, these different insulation cases are nearly ideal energysaving in Harbin，Lanzhou，Wuhan. It is also energy saving in Guangzhou，but it canrealize lower environment emissions only when the outer insulation thickness is80mm. Itis nearly to achieve energy efficiency for the external wall insulation in Kunming，however，it will increase the environment emissions in Kunming. In the perspective of the economic analysis of the full life cycle, the payback time isless than ten years in Haerbin, Lanzhou and Wuhan, so it is economic feasible in theseplaces; The life to get back the investment of the external wall insulation is nearly20yearsin Guangzhou when the external wall insulation is80mm. However, it is impossible inKunming city, this measure will cause higher investment for external wall. Compare withglass wool, the payback time of EPS is longer, and the kind of insulation material playsmore important role in Guangzhou.Thus, it can not only save cost but also can achieve energy conservation in the severecold, cold in winter and hot in summer and cold climate areas to do external wallinsulation. And it is an environmental friendly and environmental sustainable developmentwork. It is not wise to do external wall insulation in the temperate regions, the reasonablechoice of exterior insulation materials is quite important in the hot summer and warmwinter area.The life cycle of the two kinds of insulation materials evaluation studies found thatthe overall environmental impact of the EPS is superior to glass wool, just itsenvironmental releases is more, and has more obvious effect on global warming, eventhough its higher cost, it is still used more common on the market for its characteristics oflighter weight, higher thermal resistance, and the easier of production.