The results from the study are summarised in Table 1. The emission factor, in g/kg is obtained directly from measurements recorded by the portable emissions sampler. This gives the grams of particulate emissions per kilogram of fuel burned, with the fuel weight expressed on a dry weight basis. This is the same basis as is used in AS/NZS 4013 for laboratory measurements of particulate emissions.
Table 1: Summary of results for wood burners
Heater | Average emission rate (g/kg) | Fuel species | Fuel size/shape | Average moisture (%) | Pre-1994 heater replaced* |
|---|---|---|---|---|---|
1 | 4.25 | Pine | Small rounds | 18 | 2 |
2 | 4.63 | Pine | Split/off-cuts | 17 | 3 |
3 | 11.21 | Native | Split/off-cuts | 40 | n/a |
4 | 4.22 | Pine | Split | 18 | 4 |
5 | 4.89 | Pine | Split/off-cuts | 17 | n/a |
6 | 2.97 | Pine | Off-cuts | 9.5 | n/a |
7 | 3.75 | Pine | Split/off-cuts | 16 | 9 |
8 | 2.33 | Pine | Core rounds | 12 | 11 |
9 | 3.63 | Pine | Off-cuts | 19 | 12 |
* This is the number of the heater from Appendix B (Environment Waikato, 2006), which describes the results of emissions tests on households participating in the Warm Homes Pilot Project before removal of their pre-1994 wood burner. Three of the homes selected for the present study were not participants in the Warm Homes Project.