Determining the Energy Benefits from Passive Solar Design Integration through the Sensitivity Analysis of Different Case Studies

The increasing energy demand of our buildings is putting stress on the building systems and energy grids in terms of need for efficiency improvements. The maximization of the overall performance requires a multidisciplinary approach towards seeking innovative solutions to help reduce the building loads. In terms of efficient energy planning, the building design phase has often been often disregarded or looked at from a single point of view. In this case, research places its attention either on the performance of the opaque or transparent envelope to define optimization criteria. A comprehensive analysis of the impact of different passive solutions on the energy demand of buildings with different uses is the core of the present paper. The main goal is to define design guidelines for the integration of simple to complex passive configurations into the building design to help reduce the heating demand by better exploiting solar radiation. The paper gathers data from 384 simulations, on different test buildings, with the permutation of various design parameters, including window-to-wall ratio, wall heat transfer coefficient and heat capacity. Simulations were run in two different locations, typical of southern and northern Italian climate conditions, for both residential and office use. After the best solutions according to the heating or total energy performance over a nominal year were highlighted, the guidelines were applied to a case study. The aim is to determine a methodology to properly integrate passive solutions on the basis of energy performance. This performance, indeed, constitutes a tradeoff of the potential of passive systems to understand when it can be profitable to integrate these. The building analyzed, a cohousing project still in the design phase, showed that 10 to 16 % of the total energy demand can be saved. The energy saving is reached by simply integrating and declining the passive configuration suggested with marginal modifications to the initial design.