Environmental Project No. 1139 – Comparison of measurering results between solid fuel stoves tested in accordance with EN 13240 and NS 3058

Comparison of measuring results between solid fuel stoves tested in accordance with EN 13240 and NS 3058

6. Results

Connection between particle emission and CO value (appendix 2 and 3)

Appendix 2 shows the connection between the total particle emission of the NS test (i.e. the weighted average of all four burn rate categories) and the CO value of the EN test.

The graph shows a slightly increasing particle emission as a function of increasing CO value. However, R² = 0.1 is so low, that it will be uncertain to accept the comparison for a connection between CO value and particle mass.

A more obvious connection is seen if an isolated comparison is made of the NS burn rate category 1 and the CO measurement of EN (appendix 3).

Burn rate category 1 is the lowest category in the NS measurement – in Class 2 an amount of dry matter inferior to 1.25 kg per hour must be combusted.

Notoriously, category 1 is the category in which the solid fuel stove has most difficulties to meet the requirements in NS3058 (weighted mean value during all 4 burn rate categories, maximum 10 g/kg – and the highest value during one category, maximum 20 g/kg).

Appendix 3 shows a more clear connection between high CO value and high particle emission, even though the results are somewhat sporadic and the R² value of 0.36, cf. the definition above, hardly justifies a comparison between requirements on CO value and particle emission.

Connection between particle emission and THC/OGC values (appendix 4 and 5)

Even though THC/OGC is not a suitable requirement according to EN13240, we have chosen to include the results in this examination, since both parameters obviously are related to contamination.

The pattern is almost similar to the CO dependence above, because of the increasing tendency in the diagrams, both in appendix 4 and 5. However, the R² values (0.20 for NS, total, and 0.39 for NS, category 1, isolated) do not permit a firm comparison of the requirements for THC/OGC and the particle emission.