Summarize the factors affecting thermal comfort personal var

Summarize the factors affecting thermal comfort (personal variables and external factors)

Solution

Factors affecting thermal comfort:

I) Personal variables

        a) Clothing

                     Clothes insulate from exchanging heat with the surrounding air and surfaces. This affects the loss of heat through the evaporation of sweat. It can controlled because it is in the hands of person, where the external factors are not.

        b) Metabolic rate

                     This is the heat we produce through physical activity day by day. A person who doing nothing feels cool than a fellow who working.

                    

II) External factors

        a) Air temperature

                    This is the temperature of the air with which we are in contact. It is usually measured as dry bulb temperature.

        b) Air velocity

                    The velocity of air with which person is being in contact. The faster the air is moving, the greater the exchange of heat between the person and the air.

        c) Radiant temperature

                   The temperature of a person’s surroundings like surfaces, heat generating equipment, the sun and the sky.

        d) Relative humidity

                  The ratio between the actual amount of water vapor in the air and the maximum amount of water vapor that the air can hold at that air temperature expressed as a percentage. The higher the relative humidity, the more difficult it is to lose heat through the evaporation of sweat.

        e) Natural ventilation

                    This influences by how the windows are place, direction of sun rays etc.