Investigation of indoor thermal environment in the homes with elderly people during heating season in Beijing, China

- Heating systems/devices used in urban and rural houses were investigated.
- Indoor thermal environments in urban and rural houses were measured and compared.
- Clothing and thermal sensation of the elderly in urban and rural houses are assessed.
- Temperature steps encountered by the elderly were analyzed.
- The acceptable temperatures for urban and rural elderly people were discussed.

This study intends to investigate indoor thermal environment in homes with elderly people during heating season in Beijing, China. The investigation was performed from December 2016 to February 2017, involving both urban and rural houses. Heating equipment, indoor clothing and thermal sensation of the elderly, and indoor physical parameters were analyzed through subjective surveys and objective measurements. Results show that different types of heating systems/devices are used in urban and rural houses. Overall, the heating duration of rural houses is longer than that of urban houses in winter. In terms of indoor air temperature, urban elderly people experienced warmer and steadier thermal environments than rural elderly people. During the investigation, the average air temperature in living rooms/elderly people's bedrooms of urban houses was 21.9 ± 2.2 °C/21.5 ± 2.8 °C, significantly higher than 16.1 ± 3.5 °C/14.6 ± 3.3 °C of rural houses. Additionally, rural elderly people usually encountered a large temperature step between indoors and outdoors, due to frequent exit and entry. Despite of relatively low air temperatures in rural houses, the elderly reported that the indoor thermal environment was acceptable, since the elderly in rural areas wear thicker clothes indoors in winter. This also indicated the acceptable temperature for elderly people in rural areas was lower than that for elderly people in urban areas. It is noted that the acceptable temperature may not satisfy long-term physical health requirements of the elderly. More studies are needed to determine reasonable temperature for both thermal comfort and health of the elderly.