What is the Difference Between Non-catalytic and Catalytic Wood Stove Inserts?

When you begin to shop for one of the wood stove inserts, you will find that you can choose between  a catalytic or non-catalytic burner.  Both types are certified according to the EPA’s standards.  And both types burn more efficiently than the older models.  But, there are differences.

Cross section of a non-catalytic stove, showing combustion air/exhaust flow patterns, large baffle and high level combustion air supply.

Cross section of a catalytic stove, showing combustion air/exhaust flow patterns, the catalytic element, and the bypass damper.

Non-Catalytic Combustion Design in Wood Stove Inserts

Non-catalytic wood stove inserts have three characteristics that create the conditions necessary  for complete combustion.  Their features include:

Firebox insulation or lining that keeps temperatures high
A large baffle that produces a longer, hotter gas flow path by deflecting gases back into the flames so that they burn more completely
Preheated combustion air or heated secondary air supplies introduced through small holes above the fuel in the firebox.  This ensures that enough oxygen is present and the temperature remains high

Catalytic Combustion Design in Wood Stove Inserts

In catalytic combustion the smoke exhaust is passed through a coated ceramic honeycomb inside the stove where the smoke gases and particles ignite and burn.  Catalytic stoves are capable of producing a long, even heat output.

The catalytic stoves have a lever operated catalyst bypass damper, which is opened for starting and reloading.

Note:  A  catalyst is a substance that affects every action without being consumed in the process.  In wood burning stoves, exhaust gases can be routed through a catalytic combustor – a ceramic honeycomb coated with a metal such as platinum or palladium.  Smoke gases and particles pass through the combustor and ignite at a much lower temperature (250 degrees C) then they would without the combustor (500 degrees C).  The result is that harmful substances are more completely burned.  The fuel produces more heat through an extended clean burn.  However, catalyst can deteriorate over time and must be replaced.

Catalytic stoves will create more heat that is a long, even heat output.

Disadvantages to choosing the catalytic stove include the initial financial outlay.  Catalytic burners are more expensive.  You also must have more technical knowledge to operate this stove.  Another disadvantage of the catalytic burner is that the honeycomb will degrade over time and must be replaced.  But, if used properly, the catalyst can last for more than six years.

The catalyst could bread down in as little as two years if:

• The stove is over fired
• Garbage is burned in the firebox
• The stove is not cleaned on a regular basis

Overall, the non-catalytic burner will provide a brighter, more attractive fire.  You will also have to perform less maintenance and less technical knowledge is required.

Here is a good example of a non-catalytic burner.

This is the EPA approved Napolean Deluxe  Wood Burning Fireplace Insert – EPI-1402

This is what Bud from SE Pennsylvania has to say about this model:

This is the best money I ever spent. I work for an oil refinery and new the heating oil prices would be high this year. I have alot of trees on my property so wood is free. A couple of small logs and I get heat for hours. Load it up and it burns all night, 9 to 10 hours. The dual fans are quiet and installation was easy.

And from Jenn in MI:

We have a very large living room that was always cold with the use of a grate heater, and now with the insert the room is very warm. We have even turned off our furnace and have been able to circulate the heat throughout the house, to cut down on the heat bill. I would highly recommend this item!