Solo Plus & Excel Boilers

Please Note:
These boilers burn cord wood only.
Not pellets or grain.

The wood burning HS-Tarm Solo Plus and Excel boilers utilize the process of wood gasification to maximize combustion efficiency. The controls of these boilers do not allow for a low smoldering fire. They burn hot or not at all; always producing high combustion.

Because the combustion efficiency of the Solo Plus and Excel boilers is so high, the heat exchange tubes were designed for maximum heat transfer efficiency without having to be concerned with the formation of creosote in the smoke pipe or chimney. The available fuel is fully consumed and there is nothing left to waste or pass unburned up the chimney.

The Combustion Efficiency Dilemma

When considering the purchase of a wood, wood pellet, grain or corn burning hot water boiler, it is important to know how efficient the boiler is.

There are three different efficiencies to think about.

1. Combustion efficiency concerns how completely the available heat in the fuel is burned.

2. Heat Transfer efficiency concerns how completely the heat produced by combustion is transferred to the water in the boiler.

3. Over-all efficiency combines combustion efficiency and heat transfer efficiency and looks at the total picture. The higher your over-all efficiency, the less fuel or heat is wasted up the chimney.
Most wood boilers burn with either good combustion efficiency or good heat transfer efficiency, but not both. To achieve good combustion efficiency, the boiler is burned fast and hot with little smoke (unburned fuel). However, with this hot burn, the stack temperature is high with low heat transfer efficiency and substantial heat lost up the chimney.

On the other hand, good heat transfer efficiency with low stack temperatures is achieved with a slow burning fire. However, with this slow burning fire, lots of smoke and creosote are produced which is unburned fuel being lost up the chimney resulting in low combustion efficiency.

With the HS-Tarm gasification boilers, you can "have your cake and eat it too." You have both high combustion efficiency and high heat transfer efficiency resulting in high over-all efficiencies not found in most wood boilers.