September 2-4, 2026
Joining the annual academic meeting of the Society of Heating, Air-Conditioning and Sanitary Engineers of Japan.
The annual academic meeting of the Society of Heating, Air-Conditioning and Sanitary Engineers of Japan was held from Sept. 2 to 4, 2026, at the Shizuoka Institute of Science and Technology. In this meeting, a 2nd-year master’s course student, Mr. Hiroya Takeda, presented the following title.
Summary
Title: The Effectiveness of the Cumulative Heat Risk Index (HRI) in a Coffee Shop and Verification of the Benefits of Introducing the Hydrocarbon Refrigerant GF-08
Authors: Hiroya TAKEDA (Tokyo University of Science), Kengo FUJIWARA (Tokyo University of Science), Taiki UENO (Tokyo University of Science), Yoko SUGIYAMA (Starbucks Coffee Japan Co. Ltd.), Shinya YANAGITA (Tokyo University of Science), Kiyoshi DOWAKI (Tokyo University of Science)
First Author: Mr. Hiroya TAKEDA (2nd-year master’s course student)
Title: The Effectiveness of the Cumulative Heat Risk Index (HRI) in a Coffee Shop and Verification of the Benefits of Introducing the Hydrocarbon Refrigerant GF-08
Authors: Hiroya TAKEDA (Tokyo University of Science), Kengo FUJIWARA (Tokyo University of Science), Taiki UENO (Tokyo University of Science), Yoko SUGIYAMA (Starbucks Coffee Japan Co. Ltd.), Shinya YANAGITA (Tokyo University of Science), Kiyoshi DOWAKI (Tokyo University of Science)
First Author: Mr. Hiroya TAKEDA (2nd-year master’s course student)
Abstract
This study verifies the validity of the Cumulative Heat Risk Index (HRI) and the energy-saving effects of the hydrocarbon refrigerant GF-08 in a coffee shop. Results show a positive correlation between HRI and workers' heart rates, suggesting HRI is an effective indicator of thermal stress in real-world environments. Furthermore, replacing the conventional refrigerant R410A with GF-08 reduced air conditioning power consumption by 4% to 32%. These findings indicate that introducing GF-08 is an effective means of achieving both decarbonization and energy savings while maintaining a safe thermal environment for employees.
This study verifies the validity of the Cumulative Heat Risk Index (HRI) and the energy-saving effects of the hydrocarbon refrigerant GF-08 in a coffee shop. Results show a positive correlation between HRI and workers' heart rates, suggesting HRI is an effective indicator of thermal stress in real-world environments. Furthermore, replacing the conventional refrigerant R410A with GF-08 reduced air conditioning power consumption by 4% to 32%. These findings indicate that introducing GF-08 is an effective means of achieving both decarbonization and energy savings while maintaining a safe thermal environment for employees.
