Detailed comparison between two different HVAC solutions in two blocks of residential buildings: cost-benefit analysis and energy performance evaluation

The thesis is based on the work carried out during an internship experience at SEINGIM Global Service S.r.l. The work analyzes the energy performance of two new energy-efficient residential buildings, expected to be built in the city of Milan. Given the significant contribution of the buildings sector on the final energy consumption and the resulting greenhouse gases (GHG) emissions, Europe and Italy introduced progressively stricter measures to pursue sustainable development, supported by an integration of renewable energy sources (RES) and a reduction of the energy use. The primary objectives of this work concern the definition of the buildings’ envelope features to comply with the Italian regulations and LEED requirements. Using the commercial tool Edilclima, the buildings were modeled to determine the overall energy needs for heating and cooling, as well as the peak powers in both seasons, essential for sizing the HVAC system. The detailed comparison between two possible solutions of conditioning systems was initially set using an Excel tool to drive the first choices in the concept design. Afterwards the tool Edilclima has been used for a more detailed energy analysis. The two systems’ solutions examined, both in economic and energy terms, required by the client, include: (1) independent multi-split and VRF systems for each thermal zone, combined with a minor contribution from a hydronic system for the corridors’ common areas, and (2) centralized reversible hydronic heat pump systems for each building.