Performance of building energy supply systems using renewable energy

There are two types of renewable energy widely used in China: air-source heat pump and compact all glass solar vacuum pipe water heating systems. To compare the performance of these supply systems, test systems were installed on two adjacent apartment buildings with the same structure, shape, and material. Both sets of equipment were placed in the same environment for the same 31-day period. The performances and performance parameters of the systems were systematically analyzed. The system energy consumption ratio of the compact all glass solar vacuum pipe water heating system was greater than that of the air-source system on 81% of the days in the study period. However, extension theory analysis showed that the weight coefficients for the performance parameters of the two systems were equivalent over the study period. The grey relational degree between the system performance and the parameters were also calculated. The grey correlation degrees of the compact all glass solar vacuum pipe water heating system's properties with outlet temperature, inlet temperature, environment temperature, solar radiation, and sunshine time were 0.69, 0.71, 0.68, 0.70, and 0.68; and the grey correlation degrees of the air source heat pump water heating system's properties with outlet temperature, inlet temperature, environment temperature, solar radiation, and hours of sunshine were 0.71, 0.73, 0.71, 0.65, and 0.72. Furthermore, multivariate regression equations were used to study the changes of other parameters when one of the single variables changes.