This question has been the most commonly fielded questions thus far about our new stove. Below is an explanation of just what we mean by "hybrid".
Hy-brid (noun) A thing made by combining two different elements; a mixture. Hybrid is a word that is being used more frequently these days. Automakers are building hybrid gas and electric cars that increase fuel economy. Biologists have created hybrid crops that are more resilient and grow quicker. The marriage of two different technologies or ideas can lead to a product that captures the best parts of its different components. So what exactly is the Woodstock Soapstone Progress Hybrid? What elements have been combined that make this a superior wood stove? These are questions we are asked every day.
The Progress is a true hybrid because it combines a catalytic combustor with a secondary combustion system. Each of these elements is used to reduce wood stove emissions and increase efficiency. Until now, wood stoves have been using either a catalytic combustor or a secondary combustion system to meet EPA emissions standards. Each design is capable of meeting the standards by itself, so why go to the trouble and expense of developing a wood stove that combines these two separate systems? The answer lies in the way each system performs best. A catalytic combustor has the ability to break down the compounds in wood smoke at temperatures as low as 500 degrees F. This allows for more complete combustion (less pollution) at a low to moderate burn rate. The catalytic reaction produces a considerable amount of heat from the wood smoke as well producing a long, clean, and efficient burn. A secondary combustion system requires much higher temperatures ( over 1000 degrees F) to break down the same compounds in the wood smoke. These systems work most effectively at higher burn rates. The idea behind combining these two different systems in one wood stove is to capture a clean and efficient burn throughout the entire burn range.
Seems simple, right? The real trick is getting the two different systems to work effectively together and make the stove as simple to operate as possible. Through the long and winding path of R&D we have designed an air damper system that controls both primary and secondary air to the firebox using a single, simple lever. The ratio of primary to secondary air is pre-set so the user does not have to fiddle with separate knobs or levers to fine-tune the burn. The Progress will automatically deliver unused secondary air to the combustor at lower burn rates, or allow the air to combine with gases in the firebox at higher burn rates for a spectacular secondary burn. At a medium burn rate, the secondary flames and catalytic combustor alternate depending on the conditions in the firebox. Two different systems, working in harmony, make the Progress Hybrid.