New ventilation provisions in the Building Regulations will reward contractors that develop installation techniques to reduce a building’s carbon footprint, says Ian Vallely.
Ventilation plays a critical part in energy saving in buildings and, to reflect this, 1 October this year will see new provisions introduced into Part F of the Building Regulations (which is concerned specifically with ventilation). The reasons for the changes are straightforward.
Changes to Part L (conservation of fuel and power) back in 2006 introduced the concept of pressure testing and, although this was only done on a sample basis, it did make builders wake up to the fact that one in 10 of their properties were going to be pressure tested to find out where the leaks were.
That made the air tightness of the building an issue and this, in turn, placed an emphasis on controlling and managing airflow and hence heat loss. The only way to do this effectively while still keeping the building safe and comfortable is to employ some sort of powered ingress/extraction system - mechanical ventilation systems, sometimes with heat recovery. Hence the changes to Part F; the rationale is the drive towards energy efficiency through reducing energy wastage, and one way to do this is to control the airflow.
“The changes to Part F, in tandem with increased energy efficiency standards set by Part L, were inevitable and essential to keep the Government’s targets for zero-carbon buildings on track,” says managing director of Ruskin Air Management Kevin Munson.
“One of the most significant changes to Part F is the inclusion of post-completion testing of ventilation equipment with a new installation and commissioningcompliance guide. This has been introduced to ensure that ventilation not only delivers the required airflow, but does it efficiently and quietly,” says Mr Munson.
“This is a major step forward as it should ensure that the installed system is actually achieving the design requirements. It will also help to maintain indoor air quality and avoid the adverse health effects that could have occurred due to the greater tendency towards more airtight buildings arising from the changes to Part L.”
Lee Nurse of manufacturer Vent-Axia adds: “Over time, the changes to Part F will encourage continuous ventilation systems, as the increased background ventilation rates (in some instances over 50 per cent greater) make intermittent ventilation harder to apply. On top of this, the energy benefits of continuous ventilation systems in SAP will increase their adoption.”
Although he believes the Part F consultation process was conducted well, head of technical and safety at the HVCA Bob Towse is disappointed with its outcome:
“Many of the proposals in Part F that were made by the domestic ventilation industry weren’t carried forward. For example, there were talks about having a commissioning sheet that was part of Part F, a standard set of training modules, and a lot of that hasn’t gone forward, so we are very disappointed that governmentdoesn’t seem to have recognised that it has a part to play in developing this new industry.
“We are disappointed that a lot of these offers and opportunities that were made by the industry to try to help improve the domestic ventilation market weren’t really picked up.
“This is a missed opportunity, particularly as we try to head towards zero-carbon for the domestic new-build market by 2015, and controlling ventilation to reduce
energy needs is a big factor in achieving that. We may not get another one until 2013/14 and of course we now have a new government.”
For Mr Towse, the big weakness in the supply chain is the installation and commissioning section. “The Government needs to fix this for the new domestic ventilation market to work effectively, and if they don’t fix it we are going to be presented with houses that are going to need remedial action over the next 10 years.”
Ventilation industry consultant Ian Andrews thinks the distinction between controlled ventilation and demand-controlled ventilation is an important issue that has been missed in the new Part F regulations.
He explains: “Controlled ventilation usually requires some form of user intervention which can, in some instances, means that the user turns the system off [to save on the fuel bill]. However, demand-controlled ventilation requires no user intervention and ensures that the system works as intended and provides adequate, healthy
“The new Part F does not address this. Demand controlled ventilation has the potential to further reduce emissions and save energy while ensuring that the system works as intended by providing adequate ventilation.”