WIT Press

Case Study ‘the Vela Roof – UNIPOL’, Bologna: Use Of On-site Climate And Energy Resources


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WIT Press


A. van Timmeren & M. Turrin


The case study presented in this paper focuses on the so-called \“Vela roof”. This roof is part of a larger project under construction in Bologna. The focus of the study concerns the use of on-site renewable climate (energy) resources for thermal comfort with special attention given to passive cooling and heating. The very first conceptual design developed by the architectural office is assumed as a starting point for the inclusion of performance criteria at this stage in the process, taking into account a large chain of dependencies that need to be integrated in the design process. Due to extremely low wind speeds on-site, early evaluations pointed out how wind should be caught in order to provide some cooling effect; secondly, side openings at the wrong location on the roof would contribute to a green house effect more than to a passive cooling effect. As a result, in the preliminary design of the roof uncomfortable conditions were highly expected under the whole roof in the summer, with an even higher critical level in the space between the lower buildings’ roof and the Vela. Two main issues of the Vela are therefore highlighted especially related to the improvement of the existing design (configuration and shape). On one hand, in the preliminary design the overheated air was going to be kept at the top enclosed spaces without being passively extracted. On the other hand, the system of side openings could be related better to the local wind behaviour. The latter has been analyzed and digitally simulated and the first results are presented in this paper. Integration of these main issues in larger strategies was also investigated, considering both active solar technologies and passive systems for heating and cooling. Keywords: on-site renewable energy resources, urban space related comfort.


on-site renewable energy resources, urban space related comfort