11 May 2020
According to current estimates by the UK Health Alliance, outdoor air pollution contributes to around 40,000 premature deaths, over 6 million sick days and an estimated total social cost of over £20 billion per year. In 2017, the Royal College of Physicians (RCP) revealed that 44 of the 51 UK cities in the WHO’s ambient air pollution database exceed WHO’s recommended limit for air particulate matter.
Air pollution comes in three main forms: particulates; Nitrogen Oxides (NOx); and Sulphur Oxides (SOx). Much of this air pollution is caused by vehicle transport but there is also a contribution from combustion heating systems that burn gas, oil, LPG or biomass to produce heat.
In particular, air quality in the UK’s cities is a major issue. In London, the NOx pollution contribution directly from domestic and commercial gas boilers is estimated to be 16%, but that percentage is set to grow as transport becomes cleaner.
The correlation between air pollution, climate change, and health has been widely publicised and in 2018, the Royal College of General Practitioners (RCGP) announced plans to cease investment in the oil and gas sector due to climate change being a “clear risk to the health and wellbeing” of patients, placing the NHS under severe strain. The public health charity Medact describe air pollution as “comparable to tobacco in terms of the number of deaths per year for which it is responsible”.
Addressing our approach to heating and cooling existing and new buildings is therefore vital to deliver the air pollution and carbon reductions needed to improve the health and well-being of us all, and our planet.
A ground source heat pump extracts naturally occurring heat from the ground (or water) and uses it for space heating and hot water production in buildings (domestic and commercial). The heat pump itself is an electrically driven device with no combustion. There are therefore no point of use emissions of any pollution – particulates, NOx or SOx (and no point of use CO2 emissions either).
A particular benefit is the use of ground source heat pump systems in cities. As an example, if a typical three- bedroom property that consumes 12,000 kWh per year of heat was heated by a modern condensing gas combi boiler it would produce approximately 480g of NOx emissions. For older, non-condensing boilers this could be over 2kg NOx per annum.
There are estimated to be 900,000 domestic gas boilers in London. If these were all replaced with ground source heat pumps, we could reduce the NOx emissions in our city alone by over 400 tonnes per annum compared to even the best gas condensing boilers.
It is important to note that there are some NOx emissions associated with the electricity used to power the heat pump but this is falling as more of the UK’s electricity is generated from low carbon sources, including wind and solar. Heat pumps are also very efficient, producing three to four units of heat for each unit of electricity they consume.
Energy Superhub Oxford aims to install 300 ground source heat pumps in and around Oxford over the next two years, and project partner Kensa Contracting is working with affordable housing provider Stonewater to install the first sixty in Blackbird Leys shortly.
At the same time our hybrid battery energy storage system is enabling the UK’s electricity network to integrate more renewable energy, cleaning up our electricity supply so that we can all benefit from cleaner air and lower carbon emissions.
Read more about Kensa Contracing’s innovative low carbon heating solutions.