For generations, wood-burning stoves have offered warmth, comfort, self-reliance, and a connection to one of nature’s oldest renewable fuels. At Charnwood, we believe these qualities must be closely aligned with responsible design – ensuring the timeless joy of a real wood fire has a valuable place in an increasingly environmentally and health conscious world.
A proven record of facing challenges head-on
While older stoves improved on open fires, there was still significant room for improvement in terms of efficiency and emissions. As we all learned more about PM2.5, the wood-stove industry tackled the issue head-on through technological innovations including:
•Advanced firebox design
•High-efficiency combustion systems
•Precision air controls
•Intelligent microprocessor controlled stoves
Modern, Ecodesign-ready stoves now significantly reduce PM2.5 – by up to 90% in many cases when compared to older stoves and open fires. These improvements arose from dedicated innovation and a willingness to embrace new scientific insights. Thanks to independent testing and ongoing refinements, today’s stove owners can be confident their modern appliances, used appropriately, are both cleaner and more efficient than ever before. This track record underscores the integrity of our industry: we see challenges, respond with research and engineering, and deliver on our promises.
Emerging science on Ultrafine Particles (UFPs)
Now, scientific focus is turning to ultrafine particles. These are smaller than PM2.5 particles and are found everywhere. From road traffic and industrial emissions to sea spray, mushroom spores, laser printers and even the simple act of peeling citrus fruit. Their potential impacts on human health are not fully known and are still being investigated:
•UFPs can arise from activities at a distance – such as large-scale industry or busy motorways far from our homes – but the reality is that winds can carry these particles over vast areas. Pinpointing an individual source’s contribution to local air quality is extraordinarily difficult.
•The WHO determined that there was not enough data to provide guidelines for ultrafine particles (UFPs) – aerosolised particles measuring as little as 0.1 micrometers in diameter or less.(1)
•Studies and risk assessments remain inconclusive. As of now, scientists do not fully agree on the level of health risk posed by UFPs specifically, nor do we have a comprehensive understanding of each source category’s relative contribution. (2)
In this context, it is too early to claim a direct, confirmed health risk from UFPs emitted by any single source, including wood stoves—particularly as stoves contribute only a small fraction of overall UFP emissions compared to transportation, industry, and natural occurrences.
Nevertheless, at Charnwood we approach new challenges as we always have – by embracing further research. We continue to push for greater efficiency gains/emission reductions and are monitoring developments in filtration technology and beyond.
Overestimation and real-world context
As we’ve seen before with PM2.5, there is a desire from some to overestimate the impact of modern wood-burning stoves and the same will likely happen with UFPs. However, no matter the heating method – whether it’s a gas boiler, electric, heat pump, wind or solar – ultrafine particles inevitably arise somewhere along the chain including drilling, shipping, road transportation and burning for fossil fuels, large-scale manufacturing of high-tech components etc. All these processes can generate huge amounts of UFPs and other sized particles at different stages capable of contributing in varying degrees to the levels in the air.
A 2024 report by the Institute for Fiscal Studies (IFS) found that: Average PM2.5 levels in England fell by 54% between 2003 and 2023, reaching a 20-year low.(3)
Despite frequent sensational headlines, the IFS explicitly noted a tendency to “overestimate the importance of wood burning” in overall PM2.5 apportionment.
They clarified that “emissions may be dispersed by the wind or brought to the ground by rain, meaning a large emission of PM2.5 may not translate into significantly higher amounts of PM2.5 in the air we breathe … Considering only primary PM2.5 tends to overestimate the importance of wood burning as opposed to transport and energy combustion.”
By focusing broadly on “domestic wood burning” and neglecting the huge performance gap between old, inefficient stoves and modern designs, some public campaigns overlooked real opportunities to tackle air pollution more effectively. The same may prove true for UFPs, where conflating all wood-burning – regardless of technology or best practices – could distort our understanding of actual emission levels.(4)
The unique positives of Wood Burning
While every form of home heating solution has an environmental footprint somewhere along the line, only wood-burning brings such a variety of unique benefits when done responsibly:
Energy security & resilience
Wood stoves offer a degree of independence during power outages and times of high energy prices. They can heat a home even when the grid is down or gas supplies are uncertain and they don’t rely on intermittent sources such as sun and wind.
Sustainably managed woodlands
Responsible wood-burning supports active forest management. Using locally sourced firewood encourages healthy woodlands when replenished responsibly.
Lower carbon footprint (with good forestry practices)
Trees absorb carbon dioxide as they grow, making well-managed wood fuel part of a more balanced carbon cycle.
Ambience & wellbeing
There’s an intangible comfort to a wood stove’s gentle crackle and glow – a focal point that brings the family together. 93% of stove owners say it has a positive impact on their well-being(3)
(See our blog on “The Real Reason People Install a Wood Burning Stove” for more.)
Compatibility with older homes
Many traditional homes were designed with solid-fuel heating in mind. Removing or neglecting this feature can lead to inadequate ventilation and moisture problems, sometimes resulting in mould or dampness. By using a suitable wood stove, occupants can maintain the home’s historical character and proper airflow patterns.
A big future role for positive wood burning
Beyond emission numbers, positive wood burning is about family comfort, reliable energy, and the stewardship of our woodlands. At Charnwood, our mission is to safeguard this heritage while meeting and improving upon modern standards – through rigorous research, responsible innovation, and genuine care for our customers and the environment. Our success in cutting PM2.5 emissions so far shows our commitment to leading the way. As emerging science investigates UFPs, we promise to bring the same diligence to any future challenge, ensuring wood burning remains a truly sustainable, rewarding choice that gives us energy security.
We can’t – and shouldn’t – try to live in a world with zero UFPs, as they’re a natural byproduct of countless human activities and processes that are vital for progress. But we can be sensible, realistic, and evidence-based in reducing emissions where we can – just as we have done with PM2.5. With news recently that Britain’s gas storage levels are “concerningly low” it’s clear that modern wood-burning stoves have a big role to play now and in the future.(5)
References & Further Reading
1.https://www.iqair.com/newsroom/2021-WHO-air-quality-guidelines
2.https://en.wikipedia.org/wiki/Ultrafine_particle
4.https://stoveindustryassociation.org/pm2-5-levels-halved-since-2003/
6.https://www.charnwood.com/news/wood-burning-stoves-wellbeing-benefits/
7.Charnwood Blog: “The Real Reason People Install a Wood Burning Stove”
8.https://www.charnwood.com/all-stoves/room-heating-stoves/skye/skye-e700/