Suitability evaluation of cold sources in green buildings based on a field study

The cold source is important for saving building energy, especially since green buildings put forward higher requirements that the nominal coefficient of performance (COP) of the cold source should be 6% higher than that of conventional buildings. However, due to the uncontrollability of the operation stage, the actual COP generally has a gap with the nominal COP. Summarizing the operating rules of high performance cold sources and considering them in the design stage has great significance in choosing a cold source. Through continuous testing, this paper obtained the operating data of 11 green buildings' cold sources in China and proposed a suitability evaluation method for a reasonable choice of cold source. The results show that the time of ground source heat pump (GSHP) and chiller of actual hourly COP are greater than or equal to the nominal COP at 33.3% and 11.3%, respectively. Besides, it has be found that as the cold source's average load rate (ALR) increases, the ratio of measured seasonal energy efficiency ratio (SEER) to nominal COP shows an upward trend. In cases of lower ALR, when there is a significant positive correlation between electricity consumption and load rate, the ratios of the SEER to the nominal COP are higher than 0.9. Therefore, this paper proposed a suitability evaluation method. The cold source should match building loads as much as possible, but when building loads change greatly and cannot be matched, the cold source that can adjust the power consumption with the load rate should be selected.