Korean Human Thermal Sensation and Comfort Model

Effects on outdoor human comfort are an important consideration in urban and landscape planning and design. Several human thermal sensation and comfort models were developed. However, universally applicable models cannot exist because they should be modified for each climatic or cultural zone when used to assess the local effects of specific planning options. For the reason, Korean human thermal sensation and comfort models were investigated with surveying. The survey was seasonally conducted at university campuses, downtown and parks of southern Korean cities, Changwon and Daegu, in 9 times between 12:00 and 15:00 on clear days. The total participants were 892 people (male, 53.3 %; female, 47.7 %), and the survey form was prepared using ISO 10551. In the survey, five major questions were asked to participants about thermal environment: perceptual, affective evaluation, thermal preference, personal acceptability and personal tolerance. Also, four important microclimatic factors for estimating human thermal sensation were also collected in situ: air temperature, relative humidity, wind speed and short- and longwave radiation.

The air temperature was 17.2-23.9 ℃ in fall, 4.6-6.5 ℃ in winter, 27.2-29.5 ℃ in early summer and 33.6-34.3 ℃ in summer. Relative humidity was 26.3-42.6 % in fall, 18.4-38.9 % in winter and 45.1-53.3 % in early summer and summer. Wind speed was around 1.0 ms-1 in all the seasons. Radiation varied by the season and location.

In the perceptual, most Koreans felt slightly cool to warm in fall, slightly cool to cold in winter, hot in early summer and hot to very hot in summer. However, in the affective evaluation, most of them responded comfortable in fall (58.4-69.9 %) and winter (70.9-83.6 %), slightly uncomfortable in early summer (39.7-44.9 %) and slightly uncomfortable (27.1-33.3 %) to very uncomfortable (24.2-30.0 %) in summer. In the thermal preference, they preferred neither warmer nor cooler in fall (38.1-42.1 %), a little warmer in winter (42.6-45.3 %), slightly cooler in early summer (47.1-56.4 %) and cooler in summer (40.9-42.9 %). In the personal acceptability and tolerance, most people thought just acceptable and perfectly tolerable in all the seasons. These results showed that strong acclimatization existed among Koreans and that local human thermal sensation levels and its comfort levels were different. Therefore, local human thermal sensation will be more adequate levels for urban and landscape planning and design than its comfort ones. Comparison between Korean human thermal sensation and comfort models and existing models, PET and UTCI, is in progress.