A household toaster started emitting almost FIVE times more pollution than a woodburning stove , it is claimed.
Bosses at Midlands-based manufacturers Burley were responding to a recent study by the University of Sheffield which claimed stoves are having a ‘significant impact’ on indoor air quality.
Uni researchers had armed 20 households with sensors and asked them to record their solid fuel appliance usage over a four week period.
They claimed peak levels of PM2.5 occured when stove doors were opened for refuelling.
But Burley, whose tagline is that they make ‘the world’s most efficient stove’, poured cold water on these claims.
They pointed out that many stoves naturally have an increased draw when the door is open.
They claimed the increased draw will pull in particules from OTHER rooms – causing a spike in the readings, rather than it being caused by the fire itself.
In order to prove this, they did a two hour test on a Burley Brampton 8Kw stove, a toaster and 10 blown out candles on a birthday cake.
While stove PM2.5 particles peaked at 26, the toast came in at 120. But the candles reached a mindboggling PM2.5 figure of 730.
The full document can be found by clicking on the button below.
Speaking about the university’s study, Burley said: “Properly made wood burning stoves work on negative pressure.
“If a hole is drilled in the side of a stove air is drawn in, smoke does not come out. This can be easily demonstrated by opening the door ajar and holding a smoking joss stick near it.
“When the stove is not lit these other sources of particulates will not be sucked into the living room so will not be detected by the analyser, thereby leading to the incorrect assumption that the stove must be the source of the particulates.
“There is no information at all on which stoves were tested and the build quality, how they had been installed, if they comply with Ecodesign or whether the stoves were being used correctly.”
The University of Sheffield declined to comment on Burley’s document.
However, in their initial press release on the study, the uni said: “Future research needs to be done on a wider range of stove types and user groups to understand the full extent to which this indoor air pollution is occurring.”
This is quite an interesting debate, and one which you’ll never see in the media headlines, mostly because it’s very nuanced.
In a sense, Burley and the University of Sheffield are both correct.
Burley’s test shows how a properly operated appliance can work. However, it has to be pointed out it wasn’t done under strict scientific conditions and hasn’t been peer reviewed.
While this may seem a bit nitpicky to those without a scientific background, it’s important because you can end up with random results and, in some cases, not make fair comparisons.
For example, nobody really stands next to blown out candles for two hours. But nevertheless, the results are interesting in themselves and show how high levels of PM2.5 can be hiding in plain sight within the home.
The uni’s study sort of proves the point sweeps and many in the industry have been banging on about for years – that there’s a massive knowledge gap among consumers.
Many stove users don’t really know how to use their appliances as efficiently as possible, largely because they’ve never been shown.
Unlike most household appliances, solid fuel fireplaces rely on the user knowing how to operate it properly.
It’s a bit like saying a drill or a knife is dangerous. Or indeed a toaster for that matter. Well, yes of course they can be if the person using it doesn’t have a clue.
But we don’t criticise drill or knife manufacturers unless, of course, they produce something which doesn’t work properly under skilled operation.
Indeed, the university’s summary points out the following:
“Considered in the context of World Health Organisation 24h averages, some may see this as an over-reaction.
“However, many people operate log burners with the door open, they do not know about the need to minimise the time in which it is open during relighting or refuelling.”
“If technological modifications can be encouraged in order to minimise ‘flooding’ events, or the time in which the doors can be opened, then it follows that a recommendation should be made on this basis.”
That last paragraph stood out to me as there has been talk in the industry about the need for more stoves with’ active baffles’. These work by allowing greater access to the flue when the stove door is open, thus reducing the opportunity of stove spillage as it produces more draught.
Moreover though, the findings show why initiatives such as the Burnright campaign is important, as it helps people understand how to use their appliances properly.
There is also an issue which has largely come about because of the new Ecodesign standards.
These are stoves which spill smoke back into the room on refuelling. Sometimes this is done because, again, the user doesn’t understand how to refuel on more ‘efficient’ stoves which mostly do not have the ‘technological modifications’ mentioned above.
There is a trick to this – see the video below.
However there are other times this happens because the stove has, in a rush to meet Ecodesign standards, been poorly designed. This may lead to tweaks further down the line to sort out the issue.
HETAS published a call for incidents recently, which is important as some HETAS approved stoves have this very issue.
All this needs is a bit of education, which is helpful, rather than wildly exaggerated media headlines promoted by press releases which, in the university’s case, isn’t – in my view having read the study – as nuanced and balanced as the actual study report.
With the environment and air quality now firmly on the agenda, these sorts of stories aren’t going to go away.
But if it follows that we start removing logic and common sense from everything, then brace yourself for headlines demanding a ban on domestic toasters and birthday candles instead…
Mr Soot Chimney Sweep is a fully qualified sweep and a member of the Guild of Master Chimney Sweeps, based in the Manchester and South Lancs area