Thermal comfort

Thermal comfort

Human thermal comfort is a satisfaction with the surrounding thermal conditions. Thermal comfort is defined as “that condition of mind which expresses satisfaction with the thermal environment and is assessed by subjective evaluation (ANSI/ASHRAE Standard 55-2010). Thermal comfort is highly subjective to person to person. It is depends on different factor such as the air temperature, relative  humidity, radiant temperature, air velocity, metabolic rates, and clothing levels and each individual physiology, so it is difficult to measure.

The six factors affecting thermal comfort are both environmental and personal.

Determined of the thermal comfort is essential, when designing a structure that will be occupied by people. Thermal comfort is important for health and well-being as well as productivity. A lack of thermal comfort causes stress among building occupants. When they are too warm, people can feel tired; when too cold, they will be restless and distracted. Thermal comfort is calculated as a heat transfer energy balance. Heat transfer through radiation, convection, and conduction are balanced against the occupant’s metabolic rate. The heat transfer occurs between the environment and the human body. If the heat leaving from body is greater than the heat entering the body, the thermal perception is “cold.” If the heat entering the body is greater than the heat leaving from the body, the thermal perception is “warm” or “hot”.

The human body, considered as a thermodynamic system. This system requires, in healthy conditions, to maintain a constant internal temperature around 37±0.5°C, otherwise the functionality of important organs like liver, spleen, etc, may be severely damaged. So, People working in uncomfortably hot and cold environments are more likely to behave unsafely because their ability to make decisions and perform manual tasks deteriorates and the workers' ability to concentrate on a given task may start to drop off and increases the risk of errors occurring in hot environment. Based on the researches done on thermal comfort it can be conclude that thermal comfort makes a big difference to productivity. So now it is most important to know why thermal comfort is important and what we can do to achieve thermal comfort.