Wood heater particle emissions and operating efficiency standards
Cost benefit analysis
Environment Link and BDA Group
Department of the Environment and Heritage, June 2006
This report assesses the benefits and costs across six urban Australian airsheds that are likely to arise from changing national standards for particle emissions and energy efficiency for wood heaters.
Currently, most Australian jurisdictions require new wood heaters to meet the 1999 emissions standard of 4 grams of particles per kilogram (g/kg) of fuel burnt as determined by the Australian / New Zealand Standards AS/NZS 4013 – Domestic solid fuel burning appliances – Method for determination of flue gas emission. Some jurisdictions have extra measures to curb particle emissions from wood heaters. However, no jurisdiction requires wood heaters to meet a minimum efficiency standard, as none is currently specified in the Standards.
While jurisdictions have generally imposed regulations on wood heater emissions, we found limited evidence that these regulations are being enforced. In addition, the results of a recent audit of wood heaters showed that many of the wood heaters certified as being compliant with the current standard had emissions higher than permitted. In this study we assumed that compliance with any new standards will be strictly enforced. Clearly, however, the efficacy of State enforcement programs warrants separate investigation, and there would appear to be considerable air quality and public health benefits in ensuring that the wood heaters currently on the market comply with the existing emission standard.
The changes, referenced to the Australian / New Zealand Standards AS/NZS 4013 – Domestic solid fuel burning appliances – Method for determination of flue gas emission and AS/NZS 4012 – Domestic solid fuel burning appliances – Method for determination of power output and efficiency, considered in this study are emission limits of 4.0, 3.0, 2.0, 1.5 and 1 g/kg of wood burnt, as well as options for each of these emission limits with minimum operating efficiencies of 60% or 65%. Recent studies, however, have cast serious doubts over the validity of the test protocol under the current Australian/ New Zealand Standards in providing a realistic measure of how woodheaters perform in the real world under normal user operation. In addition to these emission factors, we have therefore also used emission factors derived from laboratory results using a revised test method. This revised test method, which allows only two minutes after refuelling before the combustion air is reduced and more closely simulates heaters operated in situ, is detailed in the public comment draft of the Australian/New Zealand emission standard – DR04554.
The consultancy brief specified that the airsheds of Brisbane, Canberra, Launceston, Melbourne, Perth and Sydney be assessed for impacts. We have broadly interpreted these airsheds to be those used for national reporting purposes through both the National Pollutant Inventory (NPI) and the National Environment Protection Measure for Ambient Air Quality.
We consulted many relevant studies that make assessments of the impact of PM10 both on air quality and human health and found that often they, as we did, had difficulties in matching population, health statistics and data years to PM10 airshed emissions. It would be useful to develop a consistent data set for assessing future policy options. In addition we consulted with representatives from the jurisdictions and also the wood heater industry to determine costs associated with implementation of the various standards.
Emissions of inhalable fine particles (PM10), under each scenario, have been projected out to the year 2021, along with industry, consumer and community costs and benefits associated with the new standards.