Technical and Economic Analysis of External Wall Thermal Insulation for Nearly Zero Energy Buildings Based on Life Cycle Cost

Abstract

The outer protective structure of nearly zero Energy building generally has better thermal insulation performance. With the increase of the thickness of the external wall insulation, the energy conservation gains decrease. This paper studies the economics of the life cycle cost of the external wall insulation of nearly zero energy buildings in different climate zones. Considering solar radiation and nocturnal radiation, an explicit one-dimensional unsteady heat conduction model is established by using the finite difference method, and the temperature of each point inside the wall at various times within 8760 hours of the year is calculated, thereby calculating the annual heat transfer amount per unit wall area. Considering the construction cost, annual operating cost, and discount rate, calculate the cost of the life cycle of the insulation material under different thicknesses in each climate zone. The best economic thickness of each insulation material in each climate zone is obtained.