Evaluation of passive ventilation provision in domestic housing retrofit: Fid-Bau Portal

Evaluation of passive ventilation provision in domestic housing retrofit

Kinnane, Oliver / Sinnott, Derek / Turner, William J.N.

Abstract Increasing energy efficiency in the residential sector, while maintaining adequate home ventilation for health and well-being, is proving to be a challenge. This study assesses the efficacy of passive ventilation strategies designed to comply with building regulations and imposed after housing energy-efficiency retrofits. In particular, it focuses on the provision of ventilation using background through-wall vents, which remains a common strategy in a number of European countries including Ireland and the UK, where vent sizes, related to floor area, are stipulated in building regulations. A collective of social housing, with background through-wall vents installed post thermal retrofit, is taken as a case study. These homes are modelled to interrogate the impact of the passive ventilation strategy on house air exchange rate and thermal heating energy loads. The reaction of occupants to through-wall vent installation is decidedly negative and many block vents to limit thermal discomfort and heat loss. Simulation studies show significant external air ingress through vents. A wide range of effective air change rates are observed when vents are sized without reference to building airtightness, and significant energy penalties result for the leakier homes. This study evaluates the provision of passive through-wall ventilation as part of a retrofit programme and shows it to have a number of drawbacks that may impact on the health of the building and its occupants and ultimately be at odds with the aims of achieving energy efficiency in the residential sector.

Highlights • Efficacy assessment of passive ventilation strategies complying with building regs and imposed after energy-efficiency retrofit. • Passive through-wall vents cause thermal discomfort and occupants block vents to limit their impact affecting air quality in the home. • High effective air change rates through wall vents increase space heating demand considerably. • Air tightness should be assessed as vent installation augments discomfort and energy inefficiency in leakier homes.