Room Climate Components
|The above factors
determine the heat transfer from our body to the surrounding environment,
which is mainly related to the room air temperature as shown in Figure
2 and Figure 3. The main thermal comfort variables are:
1) Temperature (air, radiant, surface) , 2) Relative Humidity, 3) Air velocity 4) Activity 5) Clothing
To maintain thermal comfort two conditions must be fulfilled.
1) the skin temperature and the body's core temperature should be thermal neutral.
2) the body's energy balance: the heat produced by the metabolism should be equal to the amount of heat lost from the body (depends on physical activities).
When PMV is either “+1.5” or
“-1.5,” as shown by the table, the Predicted Percentage Dissatisfied is
about 50% (actually, 51.5%). On the other hand, this means that nearly
one-half of the people are satisfied.When PMV is ±2.0,
then about 75 percent of people are dissatisfied. From the opposite viewpoint,
this means that about 25 percent of people are still comfortable.