NZ 'ULEB' wood heaters emit a fraction of the pollution of standard models. Why aren't they in Australia?

Australia Broadcast Center

30-07-2025

A new generation of low-emission wood heaters that can produce a fraction of the particulate pollution of current models could save lives by improving air quality, according to researchers.
But while the heaters have been on sale in New Zealand for more than a decade, and Australian clean air groups have called for their widespread adoption, they might not be widely available here for many years.
Updating pollution standards that would effectively make all new heaters sold in Australia low-emission would take up to 10 years, according to Tim Cannon, chair of a Standards Australia pollution committee.
Mr Cannon is also head of the lobby group the Australian Home Heating Association — but he said decisions on pollution standards were voted on by all members of the committee, which includes a range of perspectives.
He told the ABC he was unconvinced by recent peer-reviewed modelling that showed long-term exposure to wood-heater smoke was responsible for more than 700 premature deaths every year around the country.
But, Mr Cannon said, the committee would consider tightening pollution standards, although he was concerned that doing this too rapidly could "decimate" the industry.
"You can't just roll out changes [to wood heaters] overnight," he said.
However, Australian researchers studying the effectiveness of low-emission burners said the introduction of new low-emission heaters "could be done very rapidly" based on the NZ experience.
So what are ultra-low emission wood heaters and what impact have they had to pollution levels in New Zealand?
Ultra-low emission burners (ULEBs) cost the same and look much like traditional wood heaters, but include various technologies to improve combustion, convert more of the fuel to heat, and ultimately reduce particulate emissions.
They were introduced into New Zealand following the introduction of tougher standards, and are now undergoing testing at the University of Tasmania.
Testing has shown ULEBs are the only kind of heater that could meet more stringent emissions standards.
John Todd, a wood-heater expert taking part in the testing, said NZ wood-heater manufacturers were forced to innovate and develop ULEB designs after parts of the country introduced tight emissions controls a decade ago.
"They said they could never build heaters that could meet [ULEB emission standards] and they now have 30‒40 models that do."
The heaters have made a significant difference to the air quality of Christchurch, where the local council ran a phase-out scheme for traditional wood heaters.
Dr Todd said testing of ULEB designs on Australian hardwoods showed the heaters could emit just 10 per cent of the particulate matter (specifically particles with a diameter of 2.5 micrometres or less, known as PM2.5) generated by wood heaters complying with current Australian standards.
Fay Johnston, director of the University of Tasmania's Centre for Safe Air, said Australia could follow NZ's lead with ULEBs, along with other measures such as a phase-out of wood heaters in general in urban and high-density areas.
"There's really no reason not to adopt it and drive the same innovation and have far less-polluting heaters available for Australians," Professor Johnston, who led the testing, said.
The decision around how dirty wood heaters sold in Australia may be is largely governed by wood-heater pollution standards set by Standards Australia's "CS-062" technical committee, a group of 20 members made up mostly from industry and government.
Over the past 30 years, the committee has tightened its pollution standards, so heaters emit much less particulate matter (at least on paper) than previous designs.
Despite the change, however, air quality in areas with high wood-heater use isn't falling.
There are opposing arguments for why this is happening.
Mr Cannon said most wood heaters being used were old and built before the current tight standards.
But others, including wood-heater emissions experts such as Dr Todd, said the laboratory protocol used to test heater emissions for compliance with the Australian standards did not reflect how Australians actually used these heaters at home.
As a result, Dr Todd said, new wood heaters were up to 10 times more polluting than the standards suggested.
"No-one operates heaters the way they're being tested," he said.
"The standard assumes everyone is going to operate their heater in the best way possible."
Professor Johnston agreed.
She and others have called on the Standards Australia wood heater committee to change its compliance testing protocol, which would effectively tighten pollution standards for wood heaters.
Professor Johnston said a draft real-world testing protocol would be submitted to the standards committee by the end of the year.
"In my view, it's a long overdue [change]. We know we can get better and we haven't done it."
Mr Cannon told the ABC he was interested in the emissions research underway at the University of Tasmania, but was reluctant to tighten standards too fast.
Committee decisions are made on the basis of consensus, through voting in a formal ballot.
Mr Cannon told the ABC the industry was under attack from "health groups" such as the Centre for Safe Air.
He said reducing wood-heater emissions was politically necessary "to keep … those types of clean air scientists at bay.
The Australian Home Heating Association campaigns against local councils and state and territory governments phasing out wood-heaters via, for instance, newspaper ads and targeted social media campaigns.
"It would take five years' worth of research and then it might be five years before [ULEBs] becomes mandated in certain areas," Mr Cannon said.
"So it could be, at best, 10 years away."
Mr Cannon also said that while he was not convinced by the modelled health impacts of wood-heater smoke, he wanted to accommodate critics in order to avoid a "blanket ban on wood heaters".
"What I think and what [I do] representing our industry are not necessarily aligned," he said.
"We want to see the longevity of our industry. We could just push back [against critics], but that's going to get us nowhere.
"We have to try to be friends."
Health groups are calling for a general wood heater ban in urban and high-density areas.
Asthma Australia CEO Kate Miranda said the non-profit wanted a "phased transition away from wood-fire heaters in favour of cleaner and healthier heating alternatives" such as reverse-cycle air conditioners.
"There is no safe level of exposure [to wood smoke] and even small amounts can cause health effects and trigger asthma symptoms."
Professor Johnston said wood heaters had a role in "low-density rural areas" where the smoke could not affect large populations or neighbours, but should be banned in urban areas "where you have to buy firewood".
"We live in a highly fire-prone country. We need to manage our fuel loads," she said.
If you do have a wood heater, here are some tips to reduce, but not eliminate, smoke: