Model for Thermal Comfort and Energy Saving Based on Individual Sensation Estimation

Guillaume Lopez,Kizito Nkurikiyeyezu,Takuya Aoki,Anna Yokokubo

doi:10.18494/sam.2020.2635

Abstract

In office spaces, the ratio of energy consumption of air conditioning and lighting for maintaining the environment comfort is about 70%. On the other hand, many people claim being dissatisfied with the temperature of the air conditioning. Therefore, there is concern about work efficiency reduction caused by the current air conditioning control. In this research, we propose an automatic control system that improves both energy-saving and thermal comfort of all indoor users by quantifying individual differences in thermal comfort from vital information, on the basis of which the optimal settings of both air conditioning and wearable systems that can directly heat and cool individuals are determined. Various environments were simulated with different room sizes, numbers of users in a room, and heating/cooling conditions. The simulation results demonstrated the efficiency of the proposed system for both energy saving and comfort maximization.

Highlights

IntroductionAir conditioning accounts for the majority of energy consumption. On the other hand, several surveys reveal that many people claim being dissatisfied with the thermal office environment, leading to a decrease in productivity.[1,2] despite decades of research and the undeniable progress, the provision of thermal comfort in old buildings is still marred by problems in terms of both its quality and the amount of energy consumed.[3]
In office spaces, air conditioning accounts for the majority of energy consumption
A survey of buildings in the US, Canada, and Finland found that only 11% of the buildings achieved the recommended thermal comfort satisfaction rate.[4]. This finding agrees with those of the International Facility Management Association (IFMA) that pinpointed a high level of dissatisfaction with thermal comfort in buildings.[5] the rationale of thermal neutrality has been contested as a misleading concept since, in reality, people prefer non-neutral conditions.[6]

Summary

Introduction

Air conditioning accounts for the majority of energy consumption. On the other hand, several surveys reveal that many people claim being dissatisfied with the thermal office environment, leading to a decrease in productivity.[1,2] despite decades of research and the undeniable progress, the provision of thermal comfort in old buildings is still marred by problems in terms of both its quality and the amount of energy consumed.[3]. In the summer of 2005, the Government of Japan, through the Agency for Natural Resources and Energy, started the “cool biz” campaign, which recommends setting the room air conditioner temperature to 28 °C for energy-saving promotion,(9) instead of the usual average room temperature setting of 25 °C in about 16 thousand office buildings in the Tokyo metropolitan area. Most companies followed this guideline; several surveys showed an increase in thermal dissatisfaction rate and a reduction in productivity.[10,11] this has been accompanied by an increase in heatstroke risk owing to the hot and humid summer in Japan. When the air temperature is 30 °C and the relative humidity is 70%, the wet bulb globe temperature (WBGT, a measure of heat stress) is 29 °C, which corresponds to a risk category requiring strict vigilance according to heatstroke prevention regulations

Methods

Results

Discussion

Conclusion