An engineer from Cardiff has developed a wood-burning stove that eliminates indoor air pollution, with a UK government report finding the pellet stoves are 20 times cleaner than modern log burners. Marc Howell, founder of Island Pellet Stoves, spent seven years in his garage near Cowbridge designing a computer-controlled system that pre-heats air and automatically feeds pellets, removing the need to open the stove door during operation.
Marc Howell, a Cardiff engineering graduate who worked in the automotive and semiconductor industries, spent seven years developing the new stove in his garage near Cowbridge in the Vale of Glamorgan. The patented technology uses wood pellets made from timber industry sawdust, which contain less than 1% ash and less than 10% water.
A computer-controlled system automatically lights the pellets and feeds them from an onboard hopper into the burn pot using an Archimedes screw. Combustion air is pre-heated to a high temperature by exhaust gases through a balanced flue, similar to domestic gas boilers. Because the stove door never needs to be opened during operation, the risk of harmful pollutants entering the home is eliminated.
A report commissioned by the UK government's Department for Environment, Food and Rural Affairs (DEFRA) and published in February 2025 confirmed that Island Pellet Stoves' products are around 20 times cleaner than modern log burners for particulate emissions.
"Burning wood just had to be made more efficient and less polluting," Howell said. "Through our experiences of reducing emissions from larger scale wood pellet systems we knew there was a way to create the real wood fire experience that is so desirable in the UK but yet do it cleanly and not at the cost of harming health."
Island Pellet Stoves, which designs and manufactures its stoves in Wales, is the UK's market leader in pellet stoves.
Analysis
Why This Matters
- Indoor air pollution from wood-burning stoves is a recognised health risk; this technology offers a way to retain the warmth and aesthetic of a wood fire without the harmful side effects.
- The stoves are manufactured in Wales, supporting local engineering and manufacturing jobs.
- With UK air quality regulations tightening, a 20-times-cleaner option could become a practical standard for home heating.
Background
Wood-burning stoves are popular across the UK but produce fine particulate matter linked to respiratory and cardiovascular problems. Marc Howell, a Cardiff engineer with a background in automotive and semiconductor industries, spent seven years developing a pellet-based system that uses computer-controlled combustion to prevent pollutants entering the home. A DEFRA-commissioned study published in February 2025 verified that the stoves produce 20 times fewer particulates than modern log burners.
What to Watch
- Whether the technology is adopted more widely in the UK and exported internationally.
- Any tightening of regulations on domestic solid-fuel heating, which could accelerate demand for cleaner alternatives.
- The production capacity of Island Pellet Stoves and any plans to expand beyond the UK market.
Checked
12 claims in this story checked against 1 source: 9 supported.
Show each claim
- SupportedHowell said, “Burning wood just had to be made more efficient and less polluting.”Nation.Cymru: ““Burning wood just had to be made more efficient and less polluting” said Marc”
- SupportedHowell said the experience of reducing emissions from larger-scale pellet systems showed there was a way to create a desirable real-wood-fire experience cleanly without harming health.Nation.Cymru: ““through our experiences of reducing emissions from larger scale wood pellet systems we knew there was a way to create the real wood fire experience that is so desirable in the UK but yet do it cleanly and not at the cost of harming health’.””
- Partly supportedThe pellet stove cuts indoor pollution by 20 times, as a DEFRA report confirms.Nation.Cymru: “the pellet stoves made by Island Pellet Stoves Ltd are around 20 times cleaner than a modern log-burner for emissions of particulates.”
- Partly supportedThe stove eliminates harmful indoor emissions.Nation.Cymru: “there is no need to open the stove door during operation (as there would be with a log-burning stove) and so the risk of harmful pollutants entering the home is eliminated.”
- SupportedAn engineer from Cardiff developed the stove.Nation.Cymru: “An engineer from Cardiff has invented a new type of domestic woodburning stove”
- SupportedHowell spent seven years developing the stove in his garage near Cowbridge.Nation.Cymru: “Marc Howell ... spent seven years working in his garage near Cowbridge, Vale of Glamorgan to perfect new patented technology”
- SupportedHowell is a Cardiff engineering graduate who worked in the automotive and semiconductor industries.Nation.Cymru: “Marc Howell, who studied engineering at Cardiff University followed by years working as an engineer in the automotive and semiconductor industries”
- SupportedThe stove automatically feeds pellets from an onboard hopper with an Archimedes screw, so its door need not be opened during operation.Nation.Cymru: “The stoking or feeding of the pellets from the on-board storage hopper to the “burn-pot” is done automatically with a computer-controlled “Archimedes screw” and so there is no need to open the stove door during operation”
- SupportedThe pellets are made from timber-industry sawdust and contain less than 1% ash and less than 10% water.Nation.Cymru: “wood pellets that are manufactured from timber industry sawdust and are produced into dry, regular-shaped pellets containing less than 1% ash and less than 10% water”
- SupportedA DEFRA-commissioned report published in February 2025 confirmed the pellet stoves’ particulate-emissions comparison.Nation.Cymru: “A recent report commissioned by DEFRA (The UK Government’s Department for Food and Rural Affairs) and published in Feb 2025 called “Emission Factors for Domestic Solid Fuels” has confirmed through their testing”
- Partly supportedDEFRA is the UK government’s Department for Environment, Food and Rural Affairs.Nation.Cymru: “DEFRA (The UK Government’s Department for Food and Rural Affairs)”
- SupportedIsland Pellet Stoves designs and manufactures its stoves in Wales and is the UK’s market leader in pellet stoves.Nation.Cymru: “Island Pellet Stoves Ltd is the UK’s market leader in pellet stoves and proudly designs and manufactures its stoves in Wales.”
