FEATURE / REGULATION
Today, just as in the Victorian era of unregulated factories and smog, poverty is a factor in who is most affected by air pollution. Oliver Lord, head of policy and campaigns at Environmental Defense Fund Europe said: “The health burden of air pollution is not equal. Whether kids attend school on a main road or in a leafy suburb should not determine the quality of air they breathe, which will affect them for the rest of their lives.” The government says transport is the biggest offender, but data collected during the first lockdown in spring 2020 showed our homes and offices are also a big problem. The National Centre for Atmospheric Science calculated that during lockdown, levels of nitrogen dioxide were 43% lower in urban areas, compared to the same period over the previous five years. But there were smaller changes for small particle pollution, known as PM2.5 - which is linked to housing. The Climate Change Committee (CCC) the statutory body established under the Climate Change Act 2008, made the link. A report by its health advisory group to the government, published in November last year called for the design and retrofit of homes to be energy efficient and healthy. The CCC’s chief executive, Chris Stark, says: “There is no doubt that reducing polluting emissions has significant health benefits.”
Indoor air quality Scientists are also warning that the indoor environment is just as big a concern. Badly built, poorly maintained buildings that circulate dust or spores are just as lethal as a road full of traffic. Professor Nicola Carslaw of the University of York set out new research showing the risks. She warns that damp, the burning of fossil fuels and wood, dust, and chemicals from building materials all lower the quality of air in the place where people spend most of their time. She says: “Although
22 P&H ENGINEERING
QUARTER ONE / 2021
The health burden of air pollution is not equal people are generally very aware of air pollutants outdoors and their exposure to them – such as when they walk along a heavily trafficked street – they are much less aware that they can be exposed to pollutants in their homes.” Professor Jonathan Grigg, Paediatric Respiratory Consultant from the Royal College of Paediatrics and Child Health (RCPCH) said: “We’re finally paying attention to the quality of our indoor air, and this is long overdue. Too many of our homes and schools are damp and poorly ventilated – this is adversely affecting the health of children.” So, what can the HVAC industry do and are there any innovations that are on the way? Good building ventilation along with practical measures, such as cleaning ductwork in HVAC systems can all help. But there are bigger wins to be had. Reducing gas dependency is another factor. Boiler emissions are cited as a major source of air pollution – up to 12% in urban areas. There are 21 million gas boilers in the UK and less than 5% of homes are heated by low carbon sources. Natural gas, used mainly for heating buildings and water, accounts for 37% of all greenhouse gas emissions in London. A report by the Energy and Climate Intelligence Unit warned last autumn: “Nitrogen oxides (NOx) emission from gas boilers, could spike over the course of a winter spent working from home, potentially compromising the UK’s ability to meet legally binding air quality targets.” The Mayor of London has already been looking at this. Last year testing was carried out to compare emissions against the manufacturers’ stated emission rates for each boiler. The aim
was to start gathering data. With the exception of one boiler, measured and manufacturer’s stated emission rates compared well, with an average of 94 per cent agreement. Given killer air supply is a problem today, what can be done immediately? Right now, the best advice from the government is to meet the emission and design standards we have. For industrial boilers and furnaces in England there is a government permit scheme that sets design and limits aimed at reducing pollution. Small changes at home can make a big difference too. Professor Carslaw says: “Using an extractor fan that vents outdoors when cooking is one way to improve air quality in the home, and making sure that cleaning is carried out in a wellventilated space is another.” The CIPHE advice is to ensure that HVAC systems are maintained and cleaned so they not only remain at optimum performance but don’t pump through accumulated dust particles. Long-term, policymakers are already saying that the retro-fitting of low carbon HVAC systems, such as ground source heat pumps, is going to be part of the solution.
Finding solutions London, with a population of 8 million, is set to lead the way. A report by the Carbon Trust commissioned by Mayor Sadiq Khan published last summer set out a blueprint of how to do it. It included detailed analysis of the potential to retrofit heat pumps across a range of existing buildings in London and recommended an action plan for scaling up energy efficiency and heat pump retrofit across the capital. The report’s findings will be familiar to CIPHE members who have been following the development of the low carbon agenda over the last two years. “Heat pumps are not a like-for-like replacement for gas boilers, and good practice system design will be essential to their effective deployment,” it says.
www.ciphe.org.uk