Determination of PMV and PPD Indices

A person's well-being in an environment depends on a number of external factors. For example, humans are extremely sensitive to thermal radiation caused by cold walls or windows. Airflow in a room also creates thermal discomfort. Thermal comfort is mainly defined by the following factors: indoor air temperature and radiation temperature, air velocity and relative humidity of indoor air. In turn, the impact of these key influencing factors on a person's sense of comfort depends on their activity level and clothing.

The ISO 7730 standard published by the International Standards Organization (ISO) describes methods for estimating the general thermal sensation and degree of discomfort (level of thermal dissatisfaction) of people exposed to moderate thermal environments. The full title of this standard is: ISO 7730 Ergonomics of the thermal environment - Analytical determination and interpretation of thermal comfort using the calculation of PMV and PPD indices and local thermal comfort criteria. This standard provides analytical detection and interpretation of thermal comfort using the predicted average vote (PMV, predicted mean vote), the estimated rate of dissatisfaction (PPD, predicted percentage of dissatisfied) and the calculation of local thermal comfort. It also includes environmental conditions considered acceptable for overall thermal comfort as well as those representative of local discomfort.

PMV is an index that estimates the average climate assessment value of a large group of people. The PPD index, on the other hand, provides a quantitative estimate of the number of people who will not be satisfied with a given ambient atmosphere.

This standard is applicable to healthy men and women exposed to indoor environments where thermal comfort is desired but where there are moderate deviations from thermal comfort in the design or evaluation of environments. This standard was developed specifically for the work environment, but can also be applied to other media types.

In short, a person's thermal sensation is related to the thermal balance of his body as a whole.

Our organization also provides services for the determination of PMV and PPD indices with its trained and expert staff and advanced technological equipment, among the numerous test, measurement, analysis and evaluation studies it provides for businesses in various sectors.