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

Table 7

Comparisons between heating and cooling expenses before and after transformation of existing residential buildings in Shanghai (self-drawing).

Shanghai	Benchmark building (1980)	Roof transformation	Wall transformation	Window transformation	Reference building (meeting energy efficiency standard)
Heating: electric power (kWh/m^2)	12.47	12.17	11.73	8.98	7.91
Heating expense (Yuan/m^2)	7.60	7.42	7.16	5.48	4.83
Cooling: electric power (kWh/m^2)	9.75	9.65	9.44	9.22	8.83
Cooling expense (Yuan/m^2)	5.95	5.89	5.76	5.62	5.39
Technical information
	Air change rate: 1.5 times/hour			Air change rate: once per hour	Air change rate: once per hour