fourwalls were part of the project team for this study, led by the Zero Carbon Hub. The study team visited 33 dwellings across 6 construction sites in 2015 to see how effectively their mechanical ventilation systems were designed, installed, commissioned and handed over to occupants.
In summary, we found things going wrong at multiple stages of the construction process at every site. The cumulative effect of these issues ultimately outweighed any good practice, as the systems we tested showed significant under-performance. At 5 of the 6 sites, fans were operating at only half the required duty or lower, i.e. flow rates were far too low.
The end result was that nearly all of the 13 occupants interviewed by the team across the sites had turned off their ventilation systems, finding them too noisy, especially at night. If systems are turned off, they are not doing their job. The air quality in the property will be compromised, with potentially serious consequences for the health of occupants.