Energy-efficiency strategies of residential envelope in China's Hot Summer-Cold Winter Zone based on intermittent thermal regulation behaviour

The Hot Summer-Cold Winter Zone is a highly developed and densely populated area in China. Like many parts of the world that suffer cold and hot climate variations, the adaptive thermal comfort range here is wider than the standards, and inhabitants are accustomed to intermittent opening windows for ventilation and intermittent heating and cooling as well. Standards for residential buildings in this area are based on 24h continuous air-conditioning, resulting in large deviations between predictive effects of energy-saving technologies and actual effects. In order to achieve the energy consumption goal of 20 kWh/m(2) set for the residential buildings in this area and more accurately predict the energy-saving effects of optimized envelopes under the actual operation mode, this paper analysed optimisation strategies packages of envelopes by dynamic simulation based on residents' thermal comfort demands and intermittent behavioural characteristics. The results show that 1) compared to intermittent operation modes, the result of performance improvements of envelopes based on continuous mode may inaccurate; 2) thermal regulation behaviour optimisation can significantly reduce energy consumption; and 3) in intermittent modes, improving airtightness can save energy by 9.6%-46.7%, while the figures for envelopes and interior walls and floors are 13.6%-37.3% and 6.0%-7.9%. Seven optimisation schemes are proposed to guide the residential energy-saving design in this area. These findings could provide information for updating standards.