Comparison of Building Energy Efficiency and Life Span for Different Envelopes

Abstract

Unsuitable building energy saving technology will result in plenty building trash and waste buildings. In China, the life of many buildings is less than 50 years because of improper building heat preservation envelopes. It is found that irrational heat insulation measurement and heat preservation material position brings wall flaws and building life reduction. Comparisons of two building envelope heat insulation features are carried out by physical parameter measurements and calculation. The first is the internal heat preservation wall mode, which is mainly affected by indoor climate, and the temperature difference is generally less than 100C in a year. Second, in the external heat preservation wall mode, the temperature difference varies from 500C to 800C annually in cold and humid climates. The investigation results indicates that the external heat preservation wall mode is better compared with the internal heat preservation wall mode, and the former can effectively extend building life and provide occupants a more comfortable indoor climate. At the same time, this heat preservation technology can ensure building energy efficiency and economy. It is reasonable to adopt the external heat preservation wall mode to make the building safer and have a longer life compared with internal heat preservation. Assuming a 65% imperative national building energy saving standard calculation, the net cost is only RMB 10 Yuan increment with a 1% cost elevation due to the cost of envelope construction and heating system for the external heat preservation method.