Paul Groves looks at one of the hottest topics at the moment – indoor air quality

Improving air quality within all buildings – residential and commercial – has long been an important issue and challenge for architects, specifiers and manufacturers.

But the Covid-19 pandemic has brought the issue into much sharper focus as the long-term health benefits of properly ventilated buildings and better air quality have become more widely document

We need to give the topic of quality a proper airing

Paul Groves Paul Groves Editor of Specification magazine

Reusing energy

There is still much work to be done, although companies like Mitsubishi Electric are undoubtedly taking a lead in providing more high-quality solutions. The manufacturer recently launched has launched a residential range of Lossnay Mechanical Ventilation with Heat Recovery (MVHR) systems to provide clean and healthy air for homes.

The addition to the renowned Lossnay range is designed specifically for the UK housing market and makes energy efficient, super-quiet ventilation accessible to even more homes.

“The quality of indoor air is an important factor for health and wellbeing and the new residential Lossnay can help to ensure there is a constant flow of fresh air in our homes, and that potentially harmful pollutants and chemicals are being removed” said Hern Yau, Product Manager for Ventilation at Mitsubishi Electric. “Designed with energy efficiency in mind, the heat recovery feature also ensures as much energy as possible is reused from the extracted air.”

There is greater recognition of such issues at a governmental level too, with the long-awaited response to the 2019-20 consultation on the Future Homes Standard, which sought views on how best to improve the energy performance of new homes through changes to Part L and Part F of the Building Regulations, published by the Government. 

Lack of ambition

The Chartered Institution of Building Services Engineers (CIBSE) welcomed some of the changes in the document which are in line with the recommendation in its response to the consultation but has expressed remaining concerns about a number of the proposals.

The Future Homes Standard sets out how the government plans to improve the energy performance of new homes by 2025 with low-carbon heating and improved levels of energy efficiency.

The 2019-20 consultation was on changes to Part L (conservation of fuel and power) and Part F (ventilation) of the Building Regulations for new dwellings as the first step in achieving the Future Homes Standards and the Future Homes Standard itself. CIBSE still has concerns about a number of proposals contained in the response including.

It points to a “lack of ambition” in the proposed airtightness of 5m3/hr at 50Pa in the Future Homes Standard, which is far from being a world class level of energy efficiency. This will hold back the development of supply chains for mechanical ventilation units with heat recovery (MVHR) which would deliver energy savings and good indoor air quality, it claims.

SAGE advice

One of the country’s leading experts on airborne infection and one of the two engineer members the Scientific Advisory Group for Emergencies (SAGE), Professor Cath Noakes, told a webinar hosted by the Building Engineering Services Association (BESA) that it was not enough to simply increase ventilation rates in buildings to mitigate transmission of the Covid-19 virus.

“We don’t yet know how much ventilation we need to get this under control; we might never know that and there will always be some risk, but we can aim to reduce the residual risk as much as possible,” she told the BESA webinar. “It is not enough to just say let’s increase ventilation rates. We know it matters and will be critical for health and wellbeing (including mental health) beyond Covid so we must get this right.

“We can say we have not seen any evidence of high transmission in well-ventilated spaces – so if we are designing and delivering to the standards set in current building standards that will help, but we may need to go beyond that.”

No silver bullets

She pointed out that many buildings were not even achieving current standards and many “had no proper ventilation at all”. She also expressed particular concern about naturally ventilated spaces.

“So we might not have all the answers, but we do know we need to ventilate better,” added the Professor of Environmental Engineering for Buildings at the University of Leeds. “We also know that ventilation is forever. Even if we get this health crisis under control; what about the next one? We need to get the engineering solutions right for the long term.”

BESA’s head of technical Graeme Fox said the organisation was attempting to turn the lessons learned during the pandemic into practical measures for building owners and managers as well as engineers. 

He said the issue was complex and reinforced the urgent need for simplified, practical guidance, adding: “It also confirmed that there are no silver bullets and our industry is in the forefront of efforts to develop properly planned solutions for the long-term health and wellbeing of building occupants.” 

Paul Groves is editor of Specification magazine