Dehumidification load ratio: influence mechanism on air conditioning and energy saving potential analysis for building cooling

Abstract

The construction energy consumption (EC) makes up around 35% of the total energy used. Half of this energy is used for air-conditioning to cool spaces. The effectiveness of cooling relates to various factors, particularly the dynamic thermal performance of air-conditioners (AC) in different conditions. Studying heat pumps in diverse hot and humid climates, especially where dehumidification matters in summer AC, reveals efficiency. Examining the connection between coefficient of performance (COP) and heat removal aids in lowering building energy usage and improving cooling systems. To achieve this, a validated thermodynamic model of heat pumps and a specific transient building heat transfer model were combined. The study focused on three distinct hot and humid climate zones: Guangzhou, Wuhan, and Jiuquan. Simulations of heat pump performance were conducted throughout the year to analyze variations in COP, relative humidity (RH), and latent heat load (LHL).Key findings indicate that the COP of heat pumps is notably influenced by the practical amount of dehumidification required. A positive correlation (correlation coefficient: 0.52151) exists between COP and LHL, emphasizing the importance of addressing dehumidification needs. The research highlights that the COP remains consistently high when the heat pump manages between 45% to 80% of the LHL. Practically, these findings have crucial implications for heat pump applications and building EC reduction, particularly in regions with pronounced dehumidification requirements during the cooling season. By understanding the interplay between heat pump efficiency, humidity, and heat load, practitioners can optimize heat pump performance to achieve energy savings. This research provides a valuable reference for designing and implementing cooling systems in various hot and humid climates, facilitating energy-efficient practices and environmentally friendly building operations.