Dwelling airtightness: A socio-technical evaluation in an Irish context: Fid-Bau Portal

Dwelling airtightness: A socio-technical evaluation in an Irish context

Sinnott, Derek

Abstract This paper evaluates the relationship between envelope airtightness, correlated energy performance and occupant sensitivity pre- and post-energy efficient fabric upgrading of semi-detached social housing in Ireland. The climate corrected energy impact of the infiltration is derived from standard blower door test results and compared with modelled performance. Semi-structured interviews were used to explore the human and indoor environmental quality impact of the upgrading. Testing revealed large variations in airtightness levels and characteristics between similar dwellings. Measured and modelled airtightness results differ by up to 89%. Fabric upgrading not incorporating airtightness improvement measures yielded an average incidental 22% improvement in envelope airtightness. This equates to an estimated average 361 kWh energy savings per annum per dwelling. Occupants were generally pleased with the improvements, but many were unhappy with the ventilation systems installed as part of the upgrading. Airtightness plays an important role in the energy performance and comfort of dwellings. However, this concept is little understood by occupants and often not included as part of upgrading strategies. Further investigation is required to inform and improve energy performance calculation methodologies. There is also a need to consider the impact of upgrading works on comfort. Occupants need to be educated about the benefits of maintaining good ventilation and limiting infiltration.

Highlights • Pre-upgrading airtightness testing revealed the adopted performance model overestimated in situ airtightness by up to 89%. • Standard energy efficient upgrading does not incorporate airtightness improvement. • A co-benefit of energy efficient fabric upgrading was that envelope airtightness increased by an average 22%. • Post upgrading, 66% of the dwellings were more airtight than the nationally adopted energy performance model estimated. • Occupants were generally pleased with the upgrading, but many were unhappy with the new design ventilation.