Quantitative index for temporal and spatial patterns of occupant behavior based on VRF big data

Abstract

The energy consumption required to cool buildings has increased significantly because of occupant behavior. The air conditioning (AC) usage in residential buildings, particularly the part-time and part-space patterns, has a considerable impact on energy consumption. However, the part-time, part-space patterns of occupant behavior, which are characterized by complexity and diversity, present significant challenges when quantitatively assessing their impact on cooling energy consumption. To accurately describe occupant behavior, this study introduces the quantitative index of the part-time, part-space ratio of AC usage. We conducted clustering analysis based on part-time and part-space ratios of AC usage to obtain the typical occupant behavior patterns, user distribution, and cooling energy consumption levels of variable refrigerant flow (VRF) AC systems in various climatic zones of China based on data from 4373 VRF systems across various climatic zones from June to October 2019. The main findings were that the typical occupant behavior pattern of AC usage for residential buildings was the part-time, part-space AC mode, with less than 500 cooling hours and a simultaneous use coefficient below 0.6. The part-time, part-space ratio of AC usage effectively correlated occupant behavior with cooling energy consumption, as evidenced by an R2 value of 0.91, compared with the traditional standard of using the duration of the AC operation. The part-time, part-space ratio of AC usage and cooling energy consumption were higher in the hot summer and warm winter regions than those in the other two climatic zones. These findings can assist in the evaluation of cooling energy consumption for various occupant behavior patterns and provide technical guidance for reducing cooling energy consumption.