WHY INDOOR AIR QUALITY MATTERS AND HOW TO RESPOND

Indoor air quality (IAQ) is fundamental to the wellbeing of people and property – it’s the foundation pin of the concept of build tight, ventilate right. Sadly, despite that message having been communicated for almost 20 years, it takes events such as the COVID pandemic and the death from mould in his Rochdale home of little Awaab Ishak for it to register. Here, Ian Rogers, Sales Director at Gilberts (Blackpool), discusses further.

Rising energy costs are complicating the problem: there is a perception that ventilation means heat loss. Thus people turn extraction off prompting a deterioration of indoor air quality as moisture becomes trapped within the building. Then there is the added dimension that many non-domestic public buildings have large open spaces – atria, sports halls – that require significant energy to heat.

Climate change, too, has an impact. With more spells of heavier rain, higher humidity and wetter winters, on a wet day, if we open a window to let some fresh air in, are we actually letting more moisture in too?

In the public realm, the implications of IAQ are much wider – it affects the health of all local authority and NHS Trust buildings and the occupants of those buildings, whether staff, visitors, patients and the contents. IAQ affects infection control in hospitals through to the conservation of our heritage in museums and the stock of our libraries. It affects how much an infection spreads through a school or office.

Air quality is deteriorating. The pandemic highlighted it to the extent the World Health Organisation updated its guidelines for national and local authorities on pollutant levels1. We wouldn’t drink a glass of dirty water because we know of the dangers, but we can’t see dirt and pollutants in the air we are breathing indoors. We spend around 90% of our time inside, at work, play, living, so the air we breathe inside should be as clean as drinking water.

Building Regulations Approved Document F (updated in 2021) and the Health & Safety Executive set minimum standards for ventilation between 8-10l/p/s. Document F also raised the criteria to help improve IAQ by requiring regular servicing and maintenance of ventilation plant and CO2 sensors.

Correct airflow/ventilation protects health and the building fabric. This reduces repair and maintenance bills and helps protect the planet.

The solutions already exist, some of which you may be aware of, some you may not.

Mechanical ventilation with heat recovery (MVHR) was pioneered as long ago as 1997. As with all technology, it has evolved, its latest incarnation being hybrid ventilation with heat recovery (HVHR).

HVHR ‘ticks the boxes’ in so many ways. It predominantly relies on natural ventilation, so only uses energy when supplementing airflow with a lowenergy fan as temperatures and CO2 levels demand – such as full occupancy of an IT suite in school. It minimises heat loss by extracting warmth from the exhaust air and transferring it to the cooler, incoming fresh air. Filters remove pollutants. In certain scenarios, this can even be carbon negative. Further, most HVHR systems are ‘standalone’, so are ideally suited to new-build and refurbishment projects.

Humidity-sensitive extracts trigger only when the moisture content of the air reaches a preset, thus preventing damp build up without wasting energy. Similarly, intelligent temperature-sensitive diffusers monitor the temperature of the controlled air, redirecting the airflow to maintain the equilibrium in the room below. They require no external power source, and their quick reaction avoids heating boosting unnecessarily. Energy efficiency – and thus the building’s overall carbon footprint – is optimised.

Jet nozzles, with their long throw capability, help maintain airflow in large spaces.

Computer software now enables your M&E team to design the building services to balance energy consumption, heating, cooling and air quality and then model/test the theory before a single item is ordered.

Maintaining the IAQ without excessive heat loss nor damp requires application of balance. The tools exist to achieve that balance. The key is to work with trusted professionals in the field who can advise and support you to deliver the best air quality possible within your constraints.

www.gilbertsblackpool.com

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Source: 1https://apps.who.int/iris/bitstream/hand le/10665/345334/9789240034433-eng.pdf