Do you know how to install ventilation systems properly? The Zero Carbon Hub has done some research and guess what? Ventilation isn’t specified right or installed right.

The Zero Carbon Hub 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, the ZCH team 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 they 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.

The need to address such process-related issues is pressing. In highly efficient, airtight homes, reliance on accidental air leakage through leaky walls and windows no longer provides a safety net. It is essential that ventilation systems are designed, installed, commissioned and handed over to occupants in accordance with Building Regulations.

In common with other recent studies, our findings show that despite the availability of good practice guidance and training from Government departments, commercial companies, trade associations and professional bodies, minimum ventilation rates are still not being achieved in practice by the systems reviewed. The critical question is, why?

Consumers are acutely aware of the consequences of something going wrong with their boiler or with their electrical wiring, for example. The effects can be fatal.

It is time to borrow thinking used to improve issues with gas and electrical safety and apply similarly stringent frameworks in the ventilation sector. Failing ventilation systems may be less noticeably and immediately dangerous, but the effects over time are certainly not benign.

Look out for news of a CEW event soon to look at how to improve ventilation across Wales.