SA-12-C014 -- Long-Term Evaluation of Internal Thermal Comfort with Different Kinds of Glazing Systems and Window Sizes: From Energetic Considerations to Users' Comfort

Comfort limits are generally expressed in relation to the thermal balance of human body as a whole by two indexes proposed by Fanger in 1970:the Predicted Mean Vote, PMV, and the Predicted Percentage of Dissatisfied, PPD, which is correlated to the PMV. Inside a building three ofthe ambient parameters determining these values, i.e. the air temperature, the air humidity and the air velocity can be controlled by the system,while the mean radiant temperature depends on the surfaces temperature that means on the envelope characteristics. Glazed surfaces generally lessperforming in terms of thermal resistance than opaque components can affect the general human sensation in terms of thermal comfort. From energypoint of view the presence of large window surfaces is preferable during the heating season because solar gains through glazing can overcome heatinglosses from glazed envelope. In contrast during the cooling season more attention has to be paid in order to limit the inlet of solar radiation whichcauses the increment of cooling load. As already underlined by the authors in a previous paper, the use of particular glass types, with low thermaltransmittance and high solar factor which is the best choice for heating energy savings, can considerably worsens the cooling performance. Moreoverconsidering the user point of view, the choice of glazing type and the design of windows on a façade may depend on comfort consideration besidesenergetic evaluations. In this paper a study of internal environment conditions in a simple case study is presented considering 192 configurations foran office application in three European climates. Energetic evaluations are represented with comfort ones.