Enhancing domestic hot water energy efficiency in High-Rise residential buildings through interconnected and sharing mode

Abstract

Residential buildings in China are consuming over 20 % of their operating energy on domestic hot water (DHW), a percentage that has been increasing in recent years. The use of energy-efficient water heaters is a direct solution to reduce DHW energy consumption, but high costs and installation requirements often deter households from adopting them. This issue is particularly prevalent in high-rise residential buildings, resulting in a low adoption rate of energy-efficient water heaters in China's high-rise residential sector. To address this challenge, this study proposes a DHW interconnected and sharing mode as a novel approach to enhance DHW energy efficiency in high-rise residential buildings. A dynamic performance calculation model based on the China Energy Efficiency Label (CEEL) for various types of water heaters was developed to evaluate the energy efficiency of this mode. The total energy consumption, carbon emissions, and energy costs of the building were assessed under both decentralized mode and interconnected and sharing mode. The findings indicate that implementing the interconnected and sharing mode can significantly decrease the annual total energy consumption, carbon emissions, and energy costs of DHW. Among the two operational strategies examined (economic optimal and environmental optimal), the economic optimal strategy is more suitable for China's current energy landscape. Under the economic optimal strategy, the annual total energy consumption, carbon emissions, and energy costs of DHW in the target building are reduced by 41.58 %, 27.97 %, and 34.87%, respectively.