The energy efficiency evaluation on rehabilitated social housing buildings: Machado Vaz Neighbourhood, Porto - Portugal

Abstract

The energy efficiency evaluation as a result of the implementation of rehabilitation works in social housing buildings will be established with the calculation of the two following energy indicators: Global coefficient of heat losses through the building envelope - C(W/ºC) and Gross energy demand for heating - N(kWh). On the rehabilitation of the Machado Vaz Social Housing - this present study case, solar thermal collectors were applicated to the buildings (this was the first housing estate in Portugal equipped with this technology). The installation of solar panel allowed a final energy reduction with the production of domestic hot water throughout the year. At the present study case the energy consumption of two scenarios - pre and post rehabilitation of the buildings- will be presented, also the corresponding domestic hot water production system (AQS (KWh/year)), the savings (€/year) and the CO2 emissions calculation. As a result, it has been verified that despite the total cost of 1.022.654,82 euros of the rehabilitation works on this social housing buildings, an annual improvement of reduction in energy cost of 325.059,33 euros was achieved, which means that this investment will be recovered in a period of less than 4 years. KEYWORDS: Social housing rehabilitation, Energy efficiency evaluation, "Low cost" social habitation, Solar thermal collectors, Architectural requalification.