The report about the study has been presented at PlanExpo Green.
The topic is “Evaluation of the Impact of Retrofitting a Mid-terrace 1950s House in Dublin on Indoor Air Quality”
Whilst regulations focus on new built properties, the majority of the housing stock consists of dwellings which have been built with no particular care about ventilation, Indoor Air Quality (IAQ) or energy efficiency.
The Irish government has recently launched a consultation in order to give guidelines on how to retrofit one million homes by 2020, with an aim to improve their energy efficiency. One of the main targets is to make these homes tighter, through increased insulation, reduction of air leakage, double glazing to name the most common.
All too often, the impact of such measures on the fabric of the dwelling or on the health of the occupants is not taken into account or is underestimated. Ventilation is commonly seen as an option.
This study aims at evaluating the current situation in a typical Dublin house built in the 1950s and the impact of increased air tightness through standard and deep retrofit measures on IAQ. Various ventilation approaches are compared in the study, including typical Irish situations (permanent vents, permanent vents blocked by occupants, intermittent fans) as well as more recent approaches, such as Mechanical Extract Ventilation (MEV), Demand Controlled MEV and Heat Recovery. Ventilation heat loss is also assessed in each case.
The assessment study is based on simulations with the SIREN software (version 9). This software was developed by the CSTB for the instruction of French Technical Approvals. It offers an assessment of the energy efficiency and indoor air quality (IAQ) provided by innovative ventilation systems. This dynamic simulation tool offers a calculation method to characterise the aeraulic behaviour of a described ventilation system as well as the exposure of the occupants to various pollutants such as relative humidity, CO2 and VOCs.
The SIREN predictive model has been confirmed through a large scale experiment in Paris and Lyon (Performance de la ventilation et du bati) in 2009. This monitoring study, applied on a total of 29 occupied dwellings in two building sites, has confirmed the simulation results.