The Importance of In Situ Characterisation for the Mitigation of Poor Indoor Environmental Conditions in Social Housing

Abstract

The energy efficiency improvements in existing buildings have become priority concerns of the European Union to encourage energy efficiency amongst residents and buildings as well as facility managers. The characterisation of the building stock plays an important role in the definition of energy renovation strategies. In Portugal, there are over 120,000 social housing flats. This paper focused on the holistic characterisation of a social housing neighbourhood concerning the “in situ” assessment of the indoor environmental conditions and thermal comfort over one year as well as air permeability tests of the flats and evaluation of the energy consumption. The hygrothermal monitoring campaign was carried out using thermo-hygrometer sensors to record the indoor air temperature and relative humidity of a large number of flats over a 12-month period. The airtightness of these flats was determined resourcing fan pressurisation test (blower door test). A relationship between the users’ modifications in the flats and their consequence over the air permeability was pursued and the importance of balconies and exhaust fans for the flats’ air permeability was discussed. The hygrothermal monitoring campaign of the case study was carried out, in order to assess the indoor thermal comfort according the ASHRAE 55 standard. The results show a significant discomfort rate, suggesting that the users are living in unhealthy environmental conditions and the issues that most contribute to the poor indoor environmental conditions that characterise this building stock. In addition, the energy, gas, and water consumption of the flats were collected, and a statistical analysis was performed. Correlations between the variables were observed and two clusters were identified. Cluster 1 includes the lower energy consumption flats, but no real impact on the thermal comfort was found as the entire dataset presented low indoor air temperatures.