Homemade Green Wood Chip Furnace

Green Wood Chips Background

• Regardless of the tree varieties that are available to you, whether maple, birch, hemlock or oak, you can create green wood chips by feeding the tree parts into a wood chipper. Unlike when creating cord wood, even the smallest branches, limbs and boughs can be converted into green wood chips, which means you can make better use of the earth’s natural resources. The primary downside is that green wood chips do not produce as much heat energy as cord wood. According to the U.S. Census Bureau Business Help Site, 2,000 lbs. of green wood chips with a 50-percent moisture content can produce 10 million British thermal units (BTUs), while 2,000 lbs. of cord wood can produce 17.2 million BTUs.

Furnace Design

• Commercial green wood chip furnaces use large auger and belt systems for feeding the chips into the furnace, as well as blowers for circulating air. When building a homemade green wood chip furnace, however, you can bypass these complicated features, which are only practical for large-scale operations. At its core, a homemade green wood chip furnace needs two components: a combustion chamber for burning the chips and an insulated water or air tank for storing the heat that the combustion chamber generates. A small pump can deliver the heat from the tank to your home. Instead of using an auger and belt system for adding chips, you can add chips to a homemade green wood chip furnace manually.

Operation

• As Vermont Heat Research notes, after two hours of operation -- and four buckets of green wood chips -- a homemade green wood chip furnace can produce approximately 175,000 BTUs in a water storage tank. Furthermore, the furnace can operate efficiently, and cleanly, using composted wood chips as well as burnt wood chips that are mixed with snow. However, the heat output of the furnace is reduced when you use these fuel sources.

Benefits

• A homemade green wood chip furnace relies on an abundant fuel source -- wood -- that you can procure from your own property. This allows for significantly lower fuel costs in comparison to purchasing cord wood or wood pellets, as well as oil or gas. If you carefully manage the trees on your property, and continuously plant new ones, green wood chips can be a renewable, sustainable energy source. Apart from the fuel benefits, a green wood chip furnace produces little smoke under typical operating conditions, which means neighbors won’t need to be concerned about noxious clouds floating onto their properties.