Thermal comfort is maybe the most important and easily defined parameter of indoor environmental quality. It is largely responsible for the occupants discomfort and well being and users require a thermally comfortable environment in order to identify that a building is performing well. Thermal comfort studies declare that thermal sensation responses to a given motivation and depends upon the occupants state of thermal adaptation which correlated also on geographic location and climate, time of year, sex and many more [1].
The human body has an efficient way of regulating the temperature, which is constant at about 37oC. The surrounding environment has in most cases lower temperatures during winter and during summer higher temperatures than …show more content…
Cold regions, as north Europe, they have increased needs for heating during winter and on the other hand hot climates, as Middle East, they have higher requirements for cooling during the warm months. Therefore passive design cannot always fulfil the desire needs and mechanical means is necessary to be installed. Therefore in hot and arid climates the perceived requirement for mechanical cooling is to achieve accepted standards of thermal comfort, usually defined (directly or indirectly) by temperature limits [11]. There is, though, growing argument as to what these standards should …show more content…
Thermal comfort indicators
All projects need to provide thermally comfort environment to ensure the comfort and health of building occupants. This is achievable through the design stage by calculating the thermal comfort indicators. Indicators demonstrate that system capacity can meet the peak cooling or heating load for the worst case scenario of typical occupied spaces. A way to estimate thermal conditions of an indoor space is through formulas and equations, where a model is developed. Factors such as PMV and PPD [16] are mentioned also in international standards [9] as well as in sustainability rating systems [17].
Predicted mean vote (PMV) is the average comfort vote, using a seven-point thermal sensation scale from cold (-3) to hot (+3). When the PMV factor is equal to zero is the thermally ideal environment. This model was originally developed by collecting data from a large number of surveys on occupants in different building typologies, subjected to different conditions within a climate chamber. The comfort zone is defined by the combinations of the six key factors for thermal comfort for which the PMV is within the recommended limits (-0.5<+0.5). Correlated to this indicator, predicted percentage of dissatisfied people PPD is related to the PMV since is the indicator that establishes a quantitative prediction of the thermally dissatisfied people. PPD is based on the theory that everyone that votes -2, -3, +2 or +3 on the thermal sensation scale is dissatisfied.
The human body has an efficient way of regulating the temperature, which is constant at about 37oC. The surrounding environment has in most cases lower temperatures during winter and during summer higher temperatures than …show more content…
Cold regions, as north Europe, they have increased needs for heating during winter and on the other hand hot climates, as Middle East, they have higher requirements for cooling during the warm months. Therefore passive design cannot always fulfil the desire needs and mechanical means is necessary to be installed. Therefore in hot and arid climates the perceived requirement for mechanical cooling is to achieve accepted standards of thermal comfort, usually defined (directly or indirectly) by temperature limits [11]. There is, though, growing argument as to what these standards should …show more content…
Thermal comfort indicators
All projects need to provide thermally comfort environment to ensure the comfort and health of building occupants. This is achievable through the design stage by calculating the thermal comfort indicators. Indicators demonstrate that system capacity can meet the peak cooling or heating load for the worst case scenario of typical occupied spaces. A way to estimate thermal conditions of an indoor space is through formulas and equations, where a model is developed. Factors such as PMV and PPD [16] are mentioned also in international standards [9] as well as in sustainability rating systems [17].
Predicted mean vote (PMV) is the average comfort vote, using a seven-point thermal sensation scale from cold (-3) to hot (+3). When the PMV factor is equal to zero is the thermally ideal environment. This model was originally developed by collecting data from a large number of surveys on occupants in different building typologies, subjected to different conditions within a climate chamber. The comfort zone is defined by the combinations of the six key factors for thermal comfort for which the PMV is within the recommended limits (-0.5<+0.5). Correlated to this indicator, predicted percentage of dissatisfied people PPD is related to the PMV since is the indicator that establishes a quantitative prediction of the thermally dissatisfied people. PPD is based on the theory that everyone that votes -2, -3, +2 or +3 on the thermal sensation scale is dissatisfied.