An Airflow Output Control to Maintain a Constant Body Heat Loss During Sleep on Temperature-Changing Nights: Implementation in a Ventilated Sleep Capsule

Good sleep is essential for a healthy life. While airflow improves sleep in a hot environment, it may cause an excessive drop in body temperature because thermal-adaptive behavior is inactive during sleep. This study aims to propose an airflow control theory that prevents the excessive drop in body...

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Main Authors: Tomonori Sakoi, Masaki Kuroda, Yoshihito Kurazumi, Yoshihisa Takaoka, Kaori Narita, Sri Rahma Apriliyanthi
Format: Article
Language:English
Published: MDPI AG 2025-01-01
Series:Buildings
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Online Access:https://www.mdpi.com/2075-5309/15/3/400
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author Tomonori Sakoi
Masaki Kuroda
Yoshihito Kurazumi
Yoshihisa Takaoka
Kaori Narita
Sri Rahma Apriliyanthi
author_facet Tomonori Sakoi
Masaki Kuroda
Yoshihito Kurazumi
Yoshihisa Takaoka
Kaori Narita
Sri Rahma Apriliyanthi
author_sort Tomonori Sakoi
collection DOAJ
description Good sleep is essential for a healthy life. While airflow improves sleep in a hot environment, it may cause an excessive drop in body temperature because thermal-adaptive behavior is inactive during sleep. This study aims to propose an airflow control theory that prevents the excessive drop in body temperature while maintaining good sleep. The theory changes the heat transfer coefficient between the skin and the environment by the intensity of the fan operation to maintain a heat loss of 30 W/m<sup>2</sup> from a body with a skin temperature of 34.5 °C in a temperature-changing environment. We fabricated a ventilated sleep capsule in which this theory was embedded. Thermal manikin experiments were conducted to obtain the relationship between sensible heat transfer coefficients and the fan operating signal to establish control equations. We conducted a case study to evaluate whether the theory provided better sleep than sleeping with a regular fan running freely in homes in Ueda City, Japan, in one summer. Although the data used in the analysis were from only three subjects, the statistical analysis showed that sleeping in the ventilated sleep capsule provided better sleep, with a mean of 6% better sleep efficiency.
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spelling doaj-art-a64bc112aa1e444aaa17b0c0465634c62025-08-20T02:12:38ZengMDPI AGBuildings2075-53092025-01-0115340010.3390/buildings15030400An Airflow Output Control to Maintain a Constant Body Heat Loss During Sleep on Temperature-Changing Nights: Implementation in a Ventilated Sleep CapsuleTomonori Sakoi0Masaki Kuroda1Yoshihito Kurazumi2Yoshihisa Takaoka3Kaori Narita4Sri Rahma Apriliyanthi5Institute of Textile Science and Technology, Academic Assembly, Shinshu University, 3-15-1 Tokida, Ueda 386-8567, JapanGraduate School of Science and Technology, Shinshu University, 3-15-1 Tokida, Ueda 386-8567, JapanSchool of Life Studies, Sugiyama Jogakuen University, 17-3 Hoshigaoka-motomachi, Chikusa-ku, Nagoya 464-8662, JapanC-ENG Co., Ltd., 14-15 Chuo-honmachi, Gamagori 443-0057, JapanC-ENG Co., Ltd., 14-15 Chuo-honmachi, Gamagori 443-0057, JapanGraduate School of Medicine, Science and Technology, Shinshu University, 3-15-1 Tokida, Ueda 386-8567, JapanGood sleep is essential for a healthy life. While airflow improves sleep in a hot environment, it may cause an excessive drop in body temperature because thermal-adaptive behavior is inactive during sleep. This study aims to propose an airflow control theory that prevents the excessive drop in body temperature while maintaining good sleep. The theory changes the heat transfer coefficient between the skin and the environment by the intensity of the fan operation to maintain a heat loss of 30 W/m<sup>2</sup> from a body with a skin temperature of 34.5 °C in a temperature-changing environment. We fabricated a ventilated sleep capsule in which this theory was embedded. Thermal manikin experiments were conducted to obtain the relationship between sensible heat transfer coefficients and the fan operating signal to establish control equations. We conducted a case study to evaluate whether the theory provided better sleep than sleeping with a regular fan running freely in homes in Ueda City, Japan, in one summer. Although the data used in the analysis were from only three subjects, the statistical analysis showed that sleeping in the ventilated sleep capsule provided better sleep, with a mean of 6% better sleep efficiency.https://www.mdpi.com/2075-5309/15/3/400airflow controlsleepthermal environmenthuman body heat balanceheat transfer coefficientthermal manikin
spellingShingle Tomonori Sakoi
Masaki Kuroda
Yoshihito Kurazumi
Yoshihisa Takaoka
Kaori Narita
Sri Rahma Apriliyanthi
An Airflow Output Control to Maintain a Constant Body Heat Loss During Sleep on Temperature-Changing Nights: Implementation in a Ventilated Sleep Capsule
Buildings
airflow control
sleep
thermal environment
human body heat balance
heat transfer coefficient
thermal manikin
title An Airflow Output Control to Maintain a Constant Body Heat Loss During Sleep on Temperature-Changing Nights: Implementation in a Ventilated Sleep Capsule
title_full An Airflow Output Control to Maintain a Constant Body Heat Loss During Sleep on Temperature-Changing Nights: Implementation in a Ventilated Sleep Capsule
title_fullStr An Airflow Output Control to Maintain a Constant Body Heat Loss During Sleep on Temperature-Changing Nights: Implementation in a Ventilated Sleep Capsule
title_full_unstemmed An Airflow Output Control to Maintain a Constant Body Heat Loss During Sleep on Temperature-Changing Nights: Implementation in a Ventilated Sleep Capsule
title_short An Airflow Output Control to Maintain a Constant Body Heat Loss During Sleep on Temperature-Changing Nights: Implementation in a Ventilated Sleep Capsule
title_sort airflow output control to maintain a constant body heat loss during sleep on temperature changing nights implementation in a ventilated sleep capsule
topic airflow control
sleep
thermal environment
human body heat balance
heat transfer coefficient
thermal manikin
url https://www.mdpi.com/2075-5309/15/3/400
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