Evaluation of Annual Indoor Temperature and Humidity in Low Income Houses in Seoul, Korea

Abstract

Indoor temperature and humidity can be influenced by extreme weather conditions such as heat waves and cold spells. In developed countries, people spend 90% of their time in indoor environments. Maintaining an adequate indoor temperature and humidity is necessary to maintain health and improve the quality of life. Generally, cooling and heating systems are used to maintain and control indoor temperature and humidity conditions. However, people with a low income may be vulnerable because they may be unable to use effective cooling and heating systems in their homes. Therefore, the purpose of this study was to determine the indoor temperature and humidity in low-income households over a one-year period in Seoul, Korea. Indoor temperature and humidity were measured in three types of house (13 rooftop houses, 16 basement houses, and 18 public rental apartments) occupied by low-income residents in Seoul, Korea. The indoor temperature and humidity were continuously recorded at 30-minute intervals over a one-year period using a data logger. The indoor temperature and humidity were compared every month among the three types of residence using analysis of variance (ANOVA). The rates of compliance with indoor temperature and humidity standards were classified for four seasons according to the type of residence. Indoor temperature and relative humidity differed significantly among the three types of residence, especially during summer and winter. Among the three types of residence, the highest indoor temperature was recorded in rooftop houses during summer and the lowest during winter. During winter, indoor temperature was highest in public rental apartments. Among the three types of residence, indoor relative humidity was lowest in public rental apartments during winter. People in public rental apartments operated heating systems when the outdoor temperature was lower than 17.1°C, which was higher than the heating point in the other types of residence. Whether the indoor temperature and humidity met the compliance rate depended on the type of residence and season. The compliance rate for indoor relative humidity was met least frequently in public rental apartments during winter. However, the compliance rates for indoor absolute humidity were met least frequently during summer in all types of residence. In summer, the indoor temperature in rooftop houses was maintained at over 30°C. Moreover, the indoor temperature reached 35°C during tropical nights. The compliance rate for indoor temperatures was met least frequently in rooftop houses during winter. In addition, indoor temperature in rooftop houses displayed a similar pattern to the outdoor temperature, with a large degree of variation. This study demonstrated that occupants in low-income households were unable to control their indoor temperature and humidity conditions during summer and winter. Among the three types of house investigated, people living in rooftop houses were at the highest risk from extreme temperature and humidity conditions during summer and winter.