Human thermal comfort is defined by ASHRAE as the state of mind that expresses satisfaction with the surrounding environment (ASHRAE Standard 55). Maintaining thermal comfort for occupants of buildings or other enclosures is one of the important goals of HVAC design engineers.
Thermal comfort is affected by heat conduction, convection, radiation, and evaporative heat loss. Thermal comfort is maintained when the heat generated by human metabolism is allowed to dissipate, thus maintaining thermal equilibrium with the surroundings. Any heat gain or loss beyond this generates a sensation of discomfort. It has been long recognised that the sensation of feeling hot or cold is not just dependent on air temperature alone.
Factors determining thermal comfort include:
Personal factors (health, psychology, sociology & situational factors)
Air temperature
Mean radiant temperature
Air movement/velocity (see wind chill factor)
Relative humidity (see also perspiration)
Insulative clothing
Activity levels.
Website: http://en.wikipedia.org/wiki/Thermal_comfort
Subscribe to:
Post Comments (Atom)
No comments:
Post a Comment