As of 2015, all of Tarm's wood gasification boilers are touted to offer 80 percent or better efficiency. While this is lower than what most newer natural gas and oil boilers offer, it provides a substantial upgrade over other wood furnaces and boilers.
Fireplaces and stoves are some of the oldest methods of keeping a home warm, but they send most of the heat they generate out through the chimney. Wood-burning furnaces and boilers are traditionally placed outdoors since they produce so much particulate matter and dangerous chemicals, which pose health risks and carry away heat. Wood gasification boilers implement a second stage where energy is harnessed from the smoke and generated chemicals. As a result, these systems can use more of the energy stored within wood, and they release far less smoke.
Despite being less efficient than other heating options, wood gasification boilers allow homeowners to rely on wood for fuel, which they may have access to for free. Those who don't own sufficient forested land, however, may find the cost of wood to be higher than other fuel sources, especially when transportation costs are considered. Additionally, trees can be replanted, and trees absorb carbon dioxide as they grow. Because of this, proponents of wood as a fuel source tout wood as a carbon-neutral fuel option.