With the closing down of many public spaces as a result of the Covid-19 pandemic, focus on the air we breathe and the need to improve it has increased. As many ventilation strategies are built around the delivery of ‘fresh air’ into a building, Elta Group is highlighting the lack of clarity surrounding its definition. 

David Millward, Group product manager at Elta Group, comments: “Simply defining ‘fresh air’ as allowing outside air to circulate inside does not go far enough, as the quality is not always sufficient, nor is it immediately controllable. This can be particularly problematic in urban areas, where high levels of pollution mean that natural ventilation, such as opening a window, can bring harmful pollutants into the building.”

Contractors and those tasked with delivering ventilation solutions are being urged to play their role in changing public perception, and familiarise themselves with the latest regulations. New consultation documents for Parts L and F of the Building Regulations detail a change in emphasis towards air quality, with specific guidance on monitoring IAQ in offices.

There should be the means within ventilation systems to measure CO₂ and other air quality indicators, which helps to ensure that the ‘fresh’ air being brought in from outside is suitably healthy. There will also be specific guidance on how to ventilate certain types of buildings, or rooms in which particular activities are taking place. For example, where there is singing, exercise, or large numbers gathering, an increase in ventilation rates is likely to be required.

Demand-controlled ventilation (DCV) will play an important role as emphasis shifts to managing ventilation rates, as it facilitates the adjustment, whether that’s automatic or manual, of rates according to what is needed. This ensures that air circulation can be adapted to meet a change in occupancy levels or alterations to the internal layout of a room. It enables systems to either increase or decrease their output depending on the situation, whether that’s working up to meet compliance, or down to minimise energy costs.

Mr Millward concludes: “As we move forward, it is important that the legal definition of fresh air becomes more prescriptive, and moves away from a reliance on high-quality outdoor air. By incorporating closer monitoring of internal air and taking advantage of the latest technology, particularly in relation to DCV, we can ensure that we are meeting the demands of today while catering for the needs of the future.”