A quality marking system for pellet burners with

Certification of wood pellet domestic heating appliances in Sweden Henrik Persson SP Swedish National Testing and Research Institute Box 857 SE-501 15 BORĂ…S Sweden Tel. +46 33 16 55 21, Fax. +46 33 13 19 79, E-mail: Henrik.persson@sp.se Small scale pellet burning is today an economic competitive alternative for domestic heating.

The number of appliances sold is rapidly increasing, as well as the number of manufacturers.

There are approximately 25 000 pellet appliances in use in Sweden today and these appliances use about 100 000 tons of pellets. Today most of these appliances are pellet burners. To replace electrical heating of small houses is today a high priority task. In Sweden there are about 700 000 small houses with electrical heating. An interesting alternative is to install a pellet stove, provided with an automatic fuel feed system and which can cover a considerable part of the heating demand. There are also driving forces such as political proposals and governmental grant for replacing electrical heating with for instance pellet stoves.

Pellet heating was introduced on the Swedish market in the middle of the 90’s. At this time there were no specific system for quality marking or approval of pellet appliances. It was therefore considered important to develop such a system. In 1996, SP Swedish National Testing and Research Institute started to develop a quality marking system for pellet burners up to 25 kW heat output and in 1997 SP also developed a similar system for pellet stoves having a maximum heat output of 15 kW. The system is a P-marking system where SP is responsible for the certification system.

Certification rules and test method have been developed in cooperation with manufacturers of pellet appliances and with the authorities concerned. A project group has managed the work, which has been conducted with funding from the Swedish National Energy Administration.

The certification rules defines technical requirements with regard to safety functions, efficiency, emissions and operational reliability. Requirements concerning technical documentation and the contents of installation and operating instructions are also formulated.

In addition quality assurance in the manufacturing process is also considered. Finally the system also includes requirements on surveillance inspection.

The technical requirements were discussed with the manufacturers during a number of meetings. The certification rules and the test method were also circulated for consideration at two stages. The authorities concerned and other parties expressed also their views under way.

The test method has been validated on different appliances during the course of the project.

The P-marking system has been very positively received by both manufacturers and authorities in Sweden, and today we have 19 pellet burners and 3 pellet stoves P-marked.

Even though the P-marking is not mandatory, products that are certified dominate the market.

The P-marking system has also promoted technical development substantially and the requirements are therefore periodically reviewed.