Should We Enjoy the Weather in the Rainy Season?
Created By RISC | 2 months ago
Last modified date : 2 months ago
We often hear people ask how nice the weather is. But how can we assess meteorological conditions for human comfort?
Thermal comfort is a good place to start.
Thermal comfort is being happy with our surroundings in terms of the body's heat. It depends on 2 key aspects: 1) physical factors in the surroundings and 2) individual factors. Environmental design should provide a comfort zone, not just mentally but also physically, neither too hot nor too cold.
So what physical factors in the environment affect comfort?
4 factors must be considered:
1. Air temperature
2. Relative humidity
3. Air velocity
4. Mean radiant temperature (MRT).
During the rainy season, the air temperature drops. It mightn’t be comfortable, though, because the air is quite humid. (Read more here: https://bit.ly/3VjQysW) Our surroundings could be more comfortable if a wind is blowing. In a garden or on a lawn surrounded by trees and bushes, for example, there’s a low MRT value. We may feel cooler than when surrounded by concrete with a higher MRT, even if the temperature is the same.
In addition to comfort conditions, individual factors affect comfort. Everyone feels cold and heat differently, even in the same location. There are 2 human variables to consider:
1. Our outfit
2. Our metabolic rate
In a hot and humid country like Thailand, a T-shirt and shorts seem cooler than a long-sleeved shirt and long pants. Clothing acts as an insulator, preventing the body's heat from transferring to the surrounding environment. To assess comfort, the thermal resistance coefficient of clothing, or Clo Value, is used. The body's metabolic rate is determined by the human activities that occur in that area. The body produces heat in diverse ways, which affects a person's feeling of happiness and comfort.
The Universal Thermal Climate Index (UTCI) is used in landscape design and building exteriors to quantify human comfort and thermal stress in a variety of situations. The calculation involves 4 physical parameters of the environment: air temperature, relative humidity, wind speed, and mean residual temperature. Temperature stress has 10 levels, with the median level or no thermal stress at 9-26 °C.
There’s lots more to learn about Thailand's environmental comfort characteristics. (Read more here: https://bit.ly/3VjQysW) There’s also been a lot of research into Thai people's comfort zones. Thais are accustomed to their hot and humid climate so could find different situations pleasant from other nationalities with different climates.
Story by Panpisu Julpanwattana, Senior Sustainable Designer and TREES-A Specialist, RISC
Reference
Stein, B., & Reynolds, J. S. (1992). Mechanical and electrical equipment for buildings. New York: John Wiley & Sons.