Second reason, catalytic stoves are easier to operate than non-catalytic stoves.
A catalytic combustor begins to burn volatile materials in the exhaust stream at 500 degrees F. Non-catalytic stoves do not begin to perform efficiently until secondary air is introduced to exhaust temperatures that are over 1000 degrees F.
This is a crucial difference for two reasons...
a. The hotter you have to get your fire before you can start operating efficiently, the more heat you send up the chimney.
b. Achieving temperatures of 1000 degrees in the firebox is not easy task for every homeowner.
Getting secondary light-off in a non-catalytic can be difficult for an experienced technician in a test lab, and is much more difficult for a homeowner using cordwood of varying moisture content and density.
To achieve the advertised efficiency in a catalytic stove, all you have to do is close the catalytic by-pass damper when the exhaust stream approaches 500 degrees F. This usually takes 30-35 minutes after kindling a fire, or 15-20 minutes after reloading.
The third reason will be in my next post.