Atmosphere

Emissions from domestic solid fuel burning appliances (wood-heaters, open fireplaces)

Technical Report No. 5
J. Gras, C.Meyer, I. Weeks, R. Gillett, I. Galbally, J. Todd, F. Carnovale, R. Joynt, A. Hinwood, H. Berko and S. Brown.
Environment Australia, March 2002
ISBN 0 6425 4867 6

1. Project objectives

This study has a number of specific objectives, as outlined below:

  1. Consolidate the current state of knowledge on emissions from domestic solid-fuel- burning appliances used in Australia;
  2. Derive an estimated inventory of the types (including age and design) and quantities of wood-heaters and wood fuels currently in use throughout Australia;
  3. Gain an understanding of the emissions from a range of types of domestic solid fuel burning appliances using a variety of fuels under conditions of maximum and minimum (as permitted by the appliance); and
  4. In the context of the above data, gauge the relevance of current emission standards and guidelines (domestic and international) for wood-heaters.

2. Review of emissions data

The objective of this component is to review and consolidate current state of knowledge on emissions from domestic solid-fuel-burning appliances used in Australia.

A review of emissions data was conducted by Associate Prof. J. Todd from the University of Tasmania, under sub-contract to the project. This review is presented as Technical Report No. 4: Review of Literature on Residential Firewood Use, Wood-Smoke and Air Toxics.

3. Survey

The objective of the survey component of the study was 'to obtain a sound national survey of the number and types of wood-heaters (including open fireplaces) and wood fuels currently in use throughout (southern) Australia'.

3.1 Survey of domestic wood-heater use in southern Australia

To ensure the utmost professional standards for the survey, this component was conducted by a qualified survey agency, Strahan Research, Melbourne, using a questionnaire developed by the project in consultation with Environment Australia.

The selected methodology was a telephone survey covering the five southern states and the ACT. In order to meet the survey objectives, we anticipated completion of questionnaires by 1000 households that burnt wood in the last year. The cohort was to comprise 200 households in each of the southern states (southern Western Australia, South Australia, Victoria, Tasmania and New South Wales including the Australian Capital Territory).

Project objectives called for determination of:

The final survey questionnaire is included as Appendix 1.

Following discussions with Strahan Research and Associate Prof. John Todd, the draft survey protocol was modified to allow use of the much larger Australian Bureau of Statistics surveys that have included questions on the use of wood-heating in homes. Specifically, this determined a population-based randomisation. With this method all the major regions including cities and large rural centres are optimally represented allowing, for example, direct comparison of the fraction of wood-burning households in 2000 with earlier surveys. Taking this approach, and with the selected sample size of 1000 wood-burning households, the surveyed sample ensures 95% confidence that sample results will be within 3.1% of national population values and within 6.9% of State population values (see Appendix 2).

The report by Strahan Research covering the survey and results is attached as Appendix 2. The survey included 1007 telephone calls to wood-burning households out of a total 3,567 calls to households in the survey area, yielding 28.2% of positive respondents.

3.2 Survey of wood merchants

An additional telephone survey of firewood merchants was conducted to gain more information on species, supply of alternate fuels and the typical size of firewood sold. This covered 46 suppliers in Hobart, Melbourne, Perth, Adelaide and Canberra. This survey has clearly indicated the major commercial species for the study region. The dominant species were found to be the locally available hardwood species. In southeastern Australia this is represented by redgum, in Western Australia by jarrah and in Tasmania by a mixture of species. Softwood species were generally found to be a minor component although it is anticipated that Pinus radiata could become an increasingly significant fuel in the ACT. Consumer interest in manufactured fuels is virtually non-existent at present. A summary of results from this survey is attached as Appendix 3.