Research on the Efficiency and Economic Impact of Energy-Saving Transformation of Residential Buildings in Different Climatic Regions of China

Table 1

Parameter comparison of thermal performance of prototype buildings in Beijing (self-drawing).

Item	Benchmark building (1980)	Reference building (meeting energy efficiency standard)
Wall	value of exterior wall: 1.7 W/(m^2·K)	value of exterior wall: 0.7 W/(m^2·K)
Roof	value of roof: 1.26 W/(m^2·K)	value of roof: 0.45 W/(m^2·K)
Window	value of window: 6.4 W/(m^2·K)	value of window: 3.1 W/(m^2·K)
Air change rate	1.5 times/hour	0.5 times/hour (according to the standard for cold region)
Running time	24/7	24/7
Cooling system	Indoor air conditioner, EER: 3.1	Indoor air conditioner, EER: 3.1
Heat source (central heating)	Natural gas boiler, efficiency: 0.8	Natural gas boiler, efficiency: 0.8
Pump	Constant volume	Constant volume
Heating period	11.15–03.15 (next year)	11.15–03.15 (next year)
Cooling period	06.15–08.31	06.15–08.31