VENTILATION IN NEW HOMES A report of site visit findings

The installation and commissioning company were the same as for Site 3, hence neither the installer nor the on-site team were aware of the ADF requirement for commissioning. [...] As can be seen, despite the low performance of the fans demonstrated above, the measured air exchange rate is slightly better than the minimum required in all but Site 5 – this being the most sheltered of the sites, with the lowest wind speed on the day of measurement. [...] It is also important that the ventilation air for the dwelling exchanges through the ventilation system, thus the sum of the intake air should equal the sum of the exhaust air for the system to be in balance. [...] The additional air exchange is likely due to the air leakage of the flat (3.8 m3/(h.m2) @ 50Pa) and the effect of wind on the ventilation system. [...] Although it was evident that installers were attempting to be faithful to designs at most of the sites, the mismatch between the design and the reality of the site meant long duct runs and the use of flexible ducting, which was sometimes not pulled taut, meant the performance of the system was compromised.