During World War II, many Scandinavian cars were running on wood fuel! After the flow of oil to Norway and Sweden was cut off by the Germans, residents had to find a way to regain mobility. A simple smoker in the trunk did the job. Wood was cooked in the smoker, creating a wood gas that was piped to the carburetor.

WOOD CONSISTS OF TWO DISTINCT FUELS:

1. The combustible gases: These are given off mostly in the beginning stages of a fire after the new fuel is heated. These gases are visible as smoke and flame.



2. The fixed charcoal: These are the glowing coal-like red embers remaining after the gases have been driven from the wood..

Scientists have found that over 50% of the heat value in wood is in the form of these combustible gases. The complete burning of these gases has long been the main concern of engineers and designers seeking clean wood-burning devices.

In designing the Excel and Solo Plus Series, HS-TARM engineers decided that the best way to burn these gases was to use a firebox with two distinct chambers. In the primary chamber (firebox) the wood charge is ignited. The burning occurs at the bottom of the firebox and the heat from the fire bakes the wood above releasing the wood gas from the fuel. The combustion draft fan then blows these gases through the live coals and into the superheated ceramic tunnel where secondary air is injected to complete the burning process.

These boilers burn so clean and hot that virtually no visible smoke comes out of the chimney. The picture shown here is a close-up of the 2000 degree flame that occurs in the ceramic tunnel. How clean is clean? Tests have shown that the HS-TARM boilers can burn wood with a smoke output of less than 1 gram per hour. This is equivalent to the smoke released from one cigarette. an HS-Tarm boiler burns up to 100 times cleaner than an older woodstove. With millions of folks now burning wood it is very important that we burn it wisely.

Read on to learn more about efficiency.