Construction professionals are being urged to follow best-practice guidance when installing mechanical ventilation systems in new homes.
The Zero Carbon Hub inspected 33 properties across six construction sites to investigate how these devices were being designed and installed.
Its report – Ventilation In New Homes (PDF, 1 MB) – highlights several issues, and makes recommendations for both the building sector and Government.
The report reveals that these issues can lead to ventilation systems underperforming, causing problems with air quality and the affecting health of occupants.
According to the findings, poor installation of flexible ducting leads to fans having to work harder to deliver the minimum ventilation rates required.
As a result at five out of the six sites visited by the Zero Carbon Hub, fans were operating at just half the required power.
The Zero Carbon Hub states that on a number of its site visits, installers were found to be “doing what they’d always done”, often improvising solutions to technical issues with ventilation systems as they arose.
Installation issues uncovered by the inspections include flexible ducting being installed in place of rigid ducting, as well as long duct runs with several bends being used.
In addition, the report found there is often a fragmented delivery of the systems, with changes to things like positioning of inlets and ducts not being communicated to designers and architects.
There is also often a failure to carry out in-depth checks of ventilation systems, meaning that it would be unclear how problems could be detected if they developed.
To avoid such problems, the report recommends that developers use only trained and qualified ventilation installers.
It also states that arrangements should be put in place at the outset of a project detailing how changes to ventilation systems should be communicated to design teams.
And the Zero Carbon Hub also calls on construction professionals to ensure that checks of ventilation systems are made at each major stage of the building process.
