Blog: Air pollution and existing homes

By Wendy Thomas, residential product manager at Nuaire

Air pollution is now recognised to be the greatest environmental threat to human health in the UK. Exposure to high concentrations of pollutants is harmful to our health, and the effects are cumulative. Elderly people, children and those with existing health conditions like asthma and heart disease are particularly at risk. Reducing exposure to air pollution is now a major government initiative, but the challenge is vast.

The government has a statutory obligation to keep concentrations of some pollutants below a certain level. These are fine particulate matter (PM2.5), nitrogen dioxide (NO2 and NOX), non-methane Volatile Organic Compounds (NMVOCs), ammonia (NH3) and sulphur dioxide (SO2).

These pollutants come from many sources, including road traffic, industrial processes, agriculture and domestic fuel burning.

In a recent report by the World Health Organisation which has made headline news in the British press, it was highlighted that 37 of 43 air quality zones across the UK have failed to meet EU limits on N02. These regions will have streets or larger areas that are labelled Air Quality Management Areas or AQMAs for failing to meet air quality objectives set by government. There are currently 725 in England, 45 in Wales, 43 in Scotland and 42 in Northern Ireland, so the problem is sizable and widespread.

With what is now known about the health effects of air pollution, focus has turned to mitigation techniques to keep pollutants out of the home. Technology for air filtration in new build developments is making great strides, with highly-effective carbon filter products that work as part of a ducted Mechanical Ventilation with Heat Recovery (MVHR) system. Nuaire’s inline IAQ-BOX system, for example, removes up to 99.5% of NO2 and up to 85% of PM2.5.

Protection for occupants in newly built homes in high pollution areas already exists and, in many cases, is becoming a planning condition. But when you consider there are 27 million existing homes in the UK, compared with 170,000 new homes built each year, the disparity is clear. The industry has been waiting for a solution for the millions of existing homes that are blighted by poor air quality.

As MVHR systems with carbon filtration require ducting through the property, they are highly intrusive to install in existing homes. Many existing social housing properties are ventilated using intermittent extract fans, which are not effective at preventing the ingress of pollutants or their removal.

But now technology has been developed for existing homes. It combines a trusted technology called Positive Input Ventilation (PIV) with high-efficiency carbon filtration. It delivers clean, filtered air into the home, improving the indoor air quality to within safe levels. Nuaire’s Noxmaster is one such solution that removes up to 99.5% of NO2 and other harmful pollutants generated by traffic emissions and industrial processes.

The secret weapon here is activated carbon. The carbon media held inside a cartridge is microporous and has a much larger surface area than its external dimensions suggest. A spoonful of activated carbon equates to the surface of a football field. Through a process known as ‘adsorption’, the pollutants are attracted and held on the surface of the carbon, trapping them before they enter the home.

An additional benefit of combining carbon filtration with PIV is the reduction in humidity levels which prevents condensation dampness, and the ability to flush out pollutants generated inside the home from the use of household products, cooking with gas and burning fuel.

With growing concern over poor indoor air quality and air pollution, some homeowners are taking steps to monitor and control the air in their homes using apps and consumer air purifiers. This can lead to a false sense of security as the removal of gases and particulates from the air is a complex process. It requires mechanical ventilation and carbon filtration to treat the air throughout the home, and control the pollutants generated inside the home.

£20 billion is the estimated cost of air pollution in the UK. Reducing exposure to pollutants whilst at home can save lives and improve the quality of life. We spend an average of 16 hours a day at home, and often the most vulnerable members of our society, babies and young children and the elderly, spend substantially more time in the home.

With the right technology, the control of pollutants in existing homes is now achievable. While we wait for a long-term solution to air pollution, the new breed of mechanical ventilation systems featuring carbon filtration should help reduce diseases like asthma, heart disease and cancer, and increase life expectancy for thousands of people.