Green vs Traditional Roofs: Assessing their Actual Benefits through an Integrated Indicator Developed for Cool Roofs

Green roofs have caught on in cities, mainly because contribute positively to thermal behaviour of buildings equipped with them. This paper investigates the applicability to these roofs of an integrated indicator, developed by Levinson and Akbari, to assess the contribution of cool roofs to buildings’ energy consumption. A building, assumed as the reference for the Italian medium size offices, was considered and its energy performance with and without the green roof was assessed. Different sites with different climatic conditions were considered for the simulations. First results indicate that such indicator does not seem to be completely transferable to green roofs.

Radiative heat exchanges of people in complex geometry buildings: An experimentally based algorithm for computing angle factors

Thermal comfort of people working or living in confined spaces depends, to a large extent, on the radiative thermal exchanges. These contributions are expressed, among other things, as a function of the mean radiant temperature that, in the general cases where there is a presence of high intensity sources, must be expressed as a function of the angle factors between subjects and the surrounding surfaces of enclosures. Angle factors, in turn, depend on the projected area factors. Despite this evidence, at the present there is a lack in the availability of simple and reliable methods capable of computing angle factors of people in assigned postures with respect to complex geometry buildings. …

PV/T systems: Effect of both storage features and load configuration

PV/T panels are innovative systems increasingly used in the building sector. Their energy production and overall efficiency depend on several factors related to the shares of electrical and thermal loads and to the working temperature of the operating fluid. Therefore, an optimal configuration should be found. In this work, a parametric analysis was performed to provide a contribute on this issue. The conclusive indications can be exploited by designers and researchers, to maximize the efficiency of the systems in relation to configurations and to both electrical and thermal loads. To this purpose a simulation model was designed and implemented in a spreadsheet, using Visual BasicTM functio…

A new subjective adaptive comfort model based on intelligent agents