What is the difference between a traditional non-gasification and
EPA qualified gasification outdoor wood furnace?
Traditional “Non-Gasification” outdoor furnaces typically utilize a single heating chamber to capture rising heat over the firebox before exiting the chimney. Therefore, a significant amount of heat is lost out the chimney along with smoke and carbon emissions enabling the traditional outdoor furnace to burn with only marginal efficiency. Traditional outdoor wood furnaces have a reputation of burning almost anything put in it providing there is already a good coal bed. Although a traditional furnace may be able to burn wood with a higher moisture content, this practice requires longer and more frequent drafting which therefore also compromises it’s burn cycle of usually 10 to 12 hours at best. Although there are many traditional models still in use, they can no longer be sold for residential purposes. Non gasification outdoor furnaces however can still be sold for commercial and agriculture applications, maintaining a presumption that these users are distanced from residential areas.
Modern “Gasification” wood furnaces universally have some method of secondary combustion which facilitates ignition of unburned gasses for greater improved efficiency and lower carbon emissions. A modern wood furnace will re-burn gasses from the firebox in a matrix of plated steel or ceramic that allows combustion of these gasses at much lower temperatures than would ordinarily be possible. This is why among modern furnaces, gasification models tend to be much better at achieving low, even heat output, which achieves maximum efficiency. Drafting the flame down into a venturi for secondary gas ignition also means much less wood consumption. Therefore, many of the modern outdoor furnaces have smaller fireboxes while also affording up to a 48 hour burn cycle. WoodMaster CleanFire furnaces meet and exceed EPA requirements with some models affording 92% efficiency. Compare this with most oil fired furnaces which average around 85% efficiency to recognize a modern outdoor wood furnace as a sensible heating option. The major caveat however of gasification furnaces is they typically do not function well with wood containing more than 20% moisture content. Therefore users must exercise sufficient seasoning practices and keep wood dry before use. Some modern furnaces now offer instant phone app technical data, diagnostics, and programming which can also aid overall efficiency. The EPA has also made it attractive to buyers of qualified efficient outdoor furnaces by affording an energy tax credit toward purchase and installation.
We are always happy to discuss your specific outdoor furnace needs and welcome you to contact us at 570-378-3099 with any questions you may have.