Conference Paper

Proceedings of BSA Conference 2017: Third Conference of IBPSA-Italy

Comparison Between Energy-Optimized and Cost-Optimized Design of Multi-Family Buildings Through Automated Optimization

Maria Ferrara, Elisa Sirombo, Enrico Fabrizio

Abstract: Living in multi-family buildings is very common in Italy. Towards the implementation of economic sustainability principles, it is important to consider the effect of the design strategies in the energy demand of these buildings and their related operational costs. This is particularly important for low-income tenants, and is pursued by many social housing developments by which a good energy performance design is reached. In this work, a simulation-based optimization methodology that combines the use of TRNSYS® with GenOpt® is applied in order to minimize two different objective functions, one related to the primary energy demand and the other related to the operational energy cost, and to verify the extent to which an energy-optimized design differs from a cost-optimized design in the northern Italian climate. The study is performed on a 7-flat typical floor of a real multi-family building for social housing. The design of the building envelope is optimized, leading to reduce the primary energy demand for heating and cooling of the floor by 36 % and the energy costs by 35 %. Higher equality between the energy performances of the flats is also reached. Both objectives lead to very close values of primary energy and costs, but the resulting optimal building design is different according to optimization objective. The comparison between the energy-optimized and the cost-optimized scenarios leads to the conclusion that, in order to reduce the risk of energy poverty, the design solution that minimizes the energy cost can be preferred, as it can minimize the energy bill of low-income tenants while being close to the environmental optimum.
Pages: 309 - 316
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