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

1. Description of the Assignment

The purpose of this report is to find out whether there is a connection between the mean value of CO emission in %, measured during the EN test, and the weighted average of the particle emission, measured in the four partial courses during the NS test, stated as gram of released particles per kg of fired dry matters.

Thus, this is an attempt to compare data from the same solid fuel stove, but originating from two different tests under different test conditions. To keep the record straight we hereby give a summary of the most important differences of the two measurements:

Flue draught

During the EN test a regulated flue draught of 12 Pa is applied, whereas the NS test is carried out by natural chimney draught of the test chimney, which typically is higher.

Damper settings

During the EN test a damper setting is used, which optimizes the duration to at least 45 minutes and generates low CO and OGC values and a high CO₂ value. During the four burn rate categories of the NS test, different damper settings are applied, from almost closed to fully open, in an attempt to obtain the four required combustion rates in an interval lower than 1.25 and up to more than 2.8 kg of dry matter per hour (Class 2).

Applied fuel

Hardwood tree is applied in the EN test, and the amount is stated by the manufacturer. During the NS test conifer wood of 50 x 50 mm is used, and the amount is calculated as a function of the combustion chamber’s volume. Furthermore, it is closely defined how the NS test fuel must be cobbled up and placed, whereas it is the manufacturer who determines the shape and the placement of the EN test fuel.

In comparison, 2 kg of wood is required for a random stove tested according to EN, whereas 2.7 kg of wood is the amount of wood required for a random stove tested according to NS.