JAILCD2025-029: Study on the Actual Annual Energy Consumption of Two-Family Houses Using HEMS Data

Abstract

In recent years, household energy consumption in Japan has been on a declining trend due to changes in lifestyle, advancements in energy-efficient technologies, and national energy policies. However, the residential sector remains a major energy consumer, accounting for approximately 28.9% of total electricity consumption. This study aims to analyze real-world household energy consumption patterns, focusing on seasonal variations and key influencing factors. A field survey was conducted in a residential house equipped with a Home Energy Management System (HEMS) to collect detailed energy consumption data over 11 months. The study categorized household electricity consumption into different uses, such as heating, cooling, hot water supply, cooking, and power/lighting. Results showed that energy consumption peaks in winter, with air conditioning being the dominant electricity-consuming appliance. A significant finding was the influence of pet ownership on energy consumption; in the roadside section of the house, air conditioning was operated continuously to maintain a stable indoor temperature for pet cats, leading to higher electricity use compared to other sections. Further analysis revealed that air conditioning power consumption was closely related to outdoor temperature and human activity patterns, but continuous operation for pets resulted in relatively stable and efficient energy use. The study highlights the growing trend of pet-friendly housing and its implications for residential energy consumption.