Clearing the air in Timaru


We like our logburners in Timaru, but have we lost the art of lighting them? Features editor Claire Allison looks at ECan's latest campaign to help clean up our air.

When homo erectus figured out how to make fire work for him, he didn't need videos and step-by-step instructions. So between now and then, have we somehow lost the art of making fire?

Environment Canterbury certainly thinks so. The latest battle in the ongoing war against air pollution is a primarily social media- based campaign - More Heat, No Smoke - that aims to give people the information they need to get the most heat out of their log burner - and at the same time, limit the amount of smoke coming out of the chimney and into the atmosphere.

And that campaign goes right back to the basics of how much newspaper to use, how to put the kindling on, and when to start loading bigger pieces of wood into your burner.

Do we seriously need that amount of detail? The people involved say yes, and say that tests on various logburners, following the guidelines provided, have reduced the amount of smoke issuing from the chimney to a small amount in the first few minutes - if any at all.

The interesting thing about this campaign is that the focus is on how it will benefit the individual homeowner.

There's something in it, as it were, for everyone. Who doesn't want to get the best bang for their buck with their firewood spend?

Who wouldn't rather have a warm, comfortable home that's being well heated by their logburner, rather than huddling around a sulky burner that's failing to deliver the goods?

And if there are flow-on benefits in terms of happier neighbours and a reduction in the amount of pollution in our air - and even perhaps a pay- off in terms of less onerous sanctions being required down the track in order to comply with tough air quality targets, all the better.

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Most people know Timaru's air quality record isn't great.

Nadeine Dommisse is a principal strategy adviser with ECan, and says 88 per cent of particulate - what the layperson would call smog - in Timaru comes from home heating sources.

Across the Canterbury region, the per centage is 80 per cent.

The World Health Organisation's air quality guideline of 50mcg means that every time pollution readings go over that in a 24-hour period, it's considered a high-pollution day.

The New Zealand Government has set a target of one high-pollution day per year. So far this winter, Timaru has recorded 23 high-pollution nights.

Things have improved, says Dommisse - in the past, the number of high-pollution days exceeded 50. Last year, Timaru recorded 29. Reasons for the reduction include improvements in industry, and the ongoing replacement of older, less- efficient burners with cleaner, newer models.

"In the context of New Zealand, Timaru is one of the worst places. There are one or two others that are similar, but Timaru does have significant air-quality issues." But, says Dommisse, in terms of getting rid of older, smokier logburners, the Timaru District Council and the Timaru community itself have always been strong on a voluntary agreement, rather than a regulatory approach.

"So, in the past, we've tried to encourage people to replace older burners with cleaner models and heat pumps, and while that's made some difference, it hasn't been enough to make a significant difference."

Census data and other information show that 48 per cent of the population use wood for heating, so Dommisse says ECan has had to re- examine how to make a difference.

"How do we improve the air? And how do we do it in such a way that it's going to be with the support of the community? And a key assumption is acknowledging that wood is a cheap, sustainable long-term fuel source.

"So yes, it is a bit of a shift. We've looked at the number of woodburners, the type of woodburner, what type of fuel is being used, how they're being operated, the climate, topography, inversion layer ..." There's little that can be done about the inversion layer.

Woodburners themselves have been improved; Dommisse says an older burner would produce 4.5g of particulate per 1kg of fuel burnt - a modern burner produces 1g.

But getting the best results from the burners in use now can benefit everyone. Dommisse says while correct use of woodburners won't solve our air-quality issues, it does have the potential to make a difference.

"And the benefits are, you're not wasting your money, your neighbours are going to like you more ... most people want to do the right thing - people have been quite shocked when there's been a complaint about their smoky chimney."

"Everybody has the ability to make a difference here. We've done research and looked into it, and we've established that there could be up to a 30 per cent reduction if everybody got on board.

"That's the theory, versus everybody actually doing it, but it can have a significant impact. We're hoping to even improve by just 10 per cent, and that in itself will make a significant difference."

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Dr Emily Wilton is an air-quality scientist providing science advice to the campaign. She describes this campaign as another tool in the air- quality arena, but this time not a regulatory one.

So, how did this campaign come about?

"We do know that woodburners can be operated in such a way they can produce minimal amounts of emissions. You should see no smoke when they're being operated correctly, but if you look around, you can see that many are not being operated as well as they could be.

"Within 10 minutes of less (or lighting the burner) there should be no smoke, and even on lighting there should be very little smoke."

Those involved with the campaign have consulted New Zealand's home heating organisation experts, and have identified areas for improvement. Key points identified have been that people aren't getting their firebox hot enough really quickly, which is how to eliminate smoke.

"People aren't using enough newspaper, they're not using enough kindling, the kindling needs to be stacked and layered - like Jenga - and the whole bottom of the firebox needs to be covered in scrunched up or knotted up newspaper. And then you need lots of air.

"The aim is for your firebox to get really hot, really quickly. That's how you get rid of smoke. And once you've got your kindling and it's burned down to a charred look, then you add your first load, three to your pieces of wood, three times the size of the kindling."

Wilton says one of the biggest challenges for people is telling them to keep the air supply open for probably two hours at the start, to get the firebox as hot as possible - but possibly initially making the room too hot.

"But that gets the firebox temperature going really well, so all your wood will convert to heat. And then everything you do from that point, it's less sensitive. But every piece of wood has only X amount of energy in it, and so you're going to get less heat from that wood if it's going up the chimney."

Wilton says keeping the air supply open for two hours at the start, and then opening it up for 15 minutes or so each time the burner is re-loaded, will require a change in mindset for some people, in terms of how they use their burner.

"People often think they're doing it right, but there's sometimes a gap between that and the reality. It's quite a skill of getting the best out of your fire. But people have been really positive, they're out there wanting to learn how to use their burners properly."

Wilton says the "More heat, less smoke" campaign will not, on its own, fix Timaru's pollution problem.

"But anything we can achieve through something like this means that from a more regulatory point of view, there's maybe less that will have to be done."

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Footnote: I will freely admit to being sceptical about this campaign when I first began researching for this feature. I was pretty sure I knew what I was doing when it came to lighting my fire.

I now have to be honest enough to say that, having tried to follow the guidelines over the past couple of weeks as I've lit my own logburner at home, I'm seeing improvements.

It certainly wasn't any kind of scientific study, but I changed the way I light my fire. I use more paper and more kindling, and I let the kindling burn down more before I put any more wood on.

The single biggest change I've made, I think, is to leave the air supply on high for much longer. Before that, I'd turn it down relatively soon, figuring that meant my wood would last longer. Now, I leave it open for the suggested couple of hours.

And the results? I said it wasn't scientific - so I haven't been out in the cold trying to measure how much smoke has been coming from my chimney. But what I have noticed is that I am getting better heat from my fire. It's drying the washing on the airer in front of it much quicker, and it's heating up the house a lot better. An obvious change is the burning off of crud from the glass door - now I can actually see the fire burning through the glass.

And I don't think I'm burning any more wood than I would have been previously. I fill the log basket, and depending on what time I go to bed, there are still a couple of bits left in the bottom at the end of the night.

The Timaru Herald