Disparities of indoor temperature in winter: A cross-sectional analysis of the Nationwide Smart Wellness Housing Survey in Japan.

Wataru Umishio,Shuzo Murakami,Kazuomi Kario,Yoshihisa Fujino,Yukie Nakajima,Toshiharu Ikaga,Tanji Hoshi,Takesumi Yoshimura,Shintaro Ando,Masaru Suzuki,Hiroshi Yoshino,Tatsuhiko Kubo

doi:10.1111/ina.12708

Abstract

The WHO Housing and health guidelines recommend a minimum indoor temperature of 18°C to prevent cold‐related diseases. In Japan, indoor temperatures appear lower than in Euro‐American countries because of low insulation standards and use of partial intermittent heating. This study investigated the actual status of indoor temperatures in Japan and the common characteristics of residents who live in cold homes. We conducted a nationwide real‐world survey on indoor temperature for 2 weeks in winter. Cross‐sectional analyses involving 2190 houses showed that average living room, changing room, and bedroom temperatures were 16.8°C, 13.0°C, and 12.8°C, respectively. Comparison of average living room temperature between prefectures revealed a maximum difference of 6.7°C (Hokkaido: 19.8°C, Kagawa: 13.1°C). Compared to the high‐income group, the odds ratio for living room temperature falling below 18°C was 1.38 (95% CI: 1.04‐1.84) and 2.07 (95% CI: 1.28‐3.33) for the middle‐ and low‐income groups. The odds ratio was 1.96 (95% CI: 1.19‐3.22) for single‐person households, compared to households living with housemates. Furthermore, lower room temperature was correlated with local heating device use and a larger amount of clothes. These results will be useful in the development of prevention strategies for residents who live in cold homes.

Highlights

This study analyzed the relationship between living room temperature in the winter season and the characteristics of residents based on a Number of houses
A review of participants were at home, and the measured indoor temperature in UK homes reported that the averaverage temperature in the bedroom was 12.8°C during sleep; (b) the age living room temperature in winter was 18-21°C.10
Average living room temperature was highest (19.8°C) in Hokkaido, the Energy Follow-Up Survey 2011 involving 823 dwellings in the where outdoor temperature is lower than other areas, but lowest

Summary

Introduction

Longer period of residence in the same house (0.4°C decrease/10 year increase) and wearing larger amounts of clothes (0.3°C decrease/0.1clo increase) were correlated with lower living room temperatures.

Results

Conclusion