THERMAL COMFORT PMV/PPD:
PMV (Predicted Mean Vote) and PPD (Predicted Percentage of Dissatisfied) are indicators used to assess thermal comfort and satisfaction of indoor users. Here is more information on this:
PMV – Predicted Mean Vote: PMV is an indicator used to assess the subjective thermal sensation of a person in a given environment. It is used to determine if the thermal conditions in a room are too cold, too warm or just right. The PMV is calculated based on factors such as air temperature, surface temperature, relative humidity, air speed, and the wearer’s clothing and physical activity. The PMV score is expressed as a number, where a value close to 0 indicates optimal thermal conditions.
PPD – Predicted Percentage of Dissatisfied: PPD is an indicator that determines the percentage of people in the population who are likely to be dissatisfied with the thermal conditions in the room. The PPD is calculated based on the difference between the PMV and the preferred thermal value. The higher the PPD, the more likely it is that users will be dissatisfied with thermal conditions.
Application of PMV/PPD: In practice, PMV and PPD metrics are used to evaluate and design HVAC (Heating, Ventilation and Air Conditioning) systems to ensure optimal thermal conditions and user satisfaction. They are also used in scientific research and ergonomic evaluation to understand the impact of thermal conditions on human well-being and performance.
Guidelines and standards: There are various guidelines and standards, such as the ISO 7730 standard, that define a range of PMV and PPD values for different types of rooms and physical activities. These guidelines serve as a reference point for designers and engineers to ensure optimal thermal comfort in various environments.
PMV and PPD are tools helpful in designing HVAC systems and assessing thermal comfort inside rooms. By taking into account thermal factors and user preferences, you can strive to create friendly and comfortable thermal conditions.