For an indoor air quality study, there are a number of empirical equations used by some authors over the last few
years. Indices, such as the predicted percentage of dissatisfied with local thermal comfort, thermal sensation and
indoor air acceptability, are determined in terms of some measured parameter, such as dry bulb temperature, relative
humidity and speed of air (ISO 7730) [7].
The problem of high temperatures of air inside industrial workplaces occurs particularly during hot summer
days. Assessed workplace showed high dry air temperatures (between 32 °C and 35 °C), and high globe
temperatures (between 31 and 40 °C). This indicated high level of thermal load, occurred at workplace. By PMV
index calculation, it was proved that workers are exposed to thermal stress. The workplace was therefore assessed
by WBGT index. The average values of WBGT were obtained by statistical processing of measured data for both
measurement points. Results of statistical processing shows average values of WBGT (M1) = 33.22 °C and WBGT
(M2) = 32.84 °C. These values were compared with a referential value (refer WBGT = 28°C) found in the table in
EN 27243. From this we can state that WBGT reference value is exceeded. That means it is necessary to reduce the
heat load in the given workplace in the future.
Hot summer days are increasing the temperature inside of the building. That is why ventilation and air
conditioning systems are common. Ventilation and air condition systems are supplying or removing large volumes
of air. Ventilation can also serve to adjust the humidity and other conditions in the work environment. In many
manufacturing plants temperature and relative humidity are provided by air conditions. In these system is adjusted
by filtration, preheating or cooling or it can be humidified or dehumidified. If hot industrial facilities are not able to
provide air condition they must provide at least natural ventilation and mostly by air conditions [8].
Nowadays tropical days are more frequent and because of that it is recommended to use air conditioning in hot
industrial plants in the future.