Vermont Casting 1945 installation instructions Appendix Catalytic Combustor

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Defiant Woodburning Stove

Appendix: Catalytic Combustor

In any chemical reaction, including the combustion process, there are certain conditions which must be met before the reaction can take place. For example, a reaction may require a certain temperature, or a certain concentration of the reactants (the combustion gases and oxygen), or a certain amount of time. Catalysts act at a molecular level to change these requirements, though they are not changed themselves during the re- action. In the Defiant’s secondary combustion chamber the catalyst reduces the temperature at which second- ary combustion can start from the 1000° - 1200° F. (540° - 650° C) range to the 500° - 600°F. (260° - 315°

C)range, increasing efficiency, and reducing creosote and emissions.

The catalytic reaction does have some limitations of its own. Primary among these is that the reactants (the gases) come into close physical contact with the catalyst itself.

To ensure the necessary contact, the catalytic element in your Defiant is a ceramic base in the shape of a honeycomb. Each of the honeycomb’s many surfaces carries a coating of the catalyst (usually a noble metal such as platinum or palladium). The large surface area exposed in this way ensures that the combustion gases have the greatest opportunity to come in contact with the catalyst.

Loss of catalytic activity will be apparent in several ways. First you may notice an increase in fuel con- sumption. Second, there will be a visible increase in the rate at which creosote builds up in your chim- ney connector system. You may also notice a heavy discharge of smoke from the chimney. There are a number of catalytic problems which can cause loss of activity:

Blockage

While the honeycomb pattern ensures good contact, it also increases the resistance to flow of the combustion gases, and, because of the many surfaces, provides more places for creosote and fly ash to deposit. It is important to follow the operating instructions in order to minimize these deposits, and to periodically inspect your catalyst for signs of blockage.

Masking and Poisoning

While the catalyst itself does not enter into the combus- tion process, certain elements, such as lead and sulfur, can attach to the active sites on the surface of the hon- eycomb. Though the catalyst is still there, it is covered, or masked, by the contaminant, and cannot function.

To avoid this situation, it is important not to burn any- thing in your Defiant that is a source of these contami- nants. Particularly avoid painted or treated wood, coal,

household trash, colored papers, metal foils, or plastics. Chemical chimney cleaners may also contain harmful elements. The safest approach is to burn only untreat- ed, natural wood.

Flame Impingement

The catalytic element is not designed for exposure to direct flame. If you continually overfire your Defiant, the chemistry of the catalyst coating may be altered, inhibit- ing the combustion process. Do not use your Defiant with the baffle removed or damaged, as it shields the catalytic element from direct flame.

Thermal degradation of the ceramic base may also oc- cur, causing the element to disintegrate. Stay within the recommended guidelines of the Operation section.

Overfiring

At low firing rates, especially with a large load of fuel, the catalytic element can become overloaded with gases which do not burn in the firebox. This puts increased strain on the catalytic element, causing it to operate near or even beyond the high end of its nor- mal temperature range. An immediate sign of this is a low rumbling sound, or a sound like a small gas torch, coming from the stove’s rear chamber. If you frequently hear such a sound, or continually see a bright glow through the baffle, open up the stove’s primary air valve to make the fire burn more cleanly in the firebox, and cut back on the size of your firewood load. Essentially the catalyst is an afterburner, and will last longer under lighter loads.

Mechanical Damage

If the element is mishandled, damage may occur. Always treat the element carefully. Remember the catalyst is made of a ceramic material; treat it as you would fine china. Hairline cracks will not affect the performance of the catalyst, as long as the steel sleeve holds the element in the proper position.

Peeling

The surface coat may peel if the catalytic element is frequently subjected to excessive temperatures. Follow the operating instructions carefully to avoid this type of damage.

General

Every Vermont Castings’ Defiant is equipped with either

aCorning “Long-Life”®or an Applied Ceramics combus- tor. The products are equivalent.

If you must ship your catalytic element for any reason, remember its fragile nature. Place the element in a plastic bag, and package it with a generous amount of shock absorbing material.

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Contents Defiant Welcome Save These Instructions for Future ReferenceInstallation Accessories Table of ContentsStory of the Defiant Specifications Defiant, ModelOutside Air InstallationChimney Height Prefabricated Chimneys What Kind of Chimney to UseMasonry Chimneys Chimney SizeSecuring the Single-wall Connector to a Masonry Chimney Chimney Connector GuidelinesSingle-wall Chimney Connectors Freestanding InstallationsFireplace Installations Above the FireplaceThrough the Fireplace Wall Pass-ThroughsFloor Protection for Fireplace Installation Floor ProtectionSafe Ways to Reduce Clearances Keep the Stove a Safe Distance from Sur Rounding MaterialsWall Shields Fireplace and Mantel Trim Shields Fireplace and Mantel Trim ClearancesDefiant Clearance Chart Stove Clearance Unprotected Surfaces Protected SurfacesDefiant Clearance Diagrams Unprotected Surfaces Protected SurfacesStove Heat Shields Distance from the Center of the Flue Collar to the Wall Defiant With Rear Heat Shield onlyInstall Stove Legs AssemblySet Up Your Stove Install the Optional Bottom Heat ShieldOperation Defiant ControlsDamper Directs Air Flow Within the Stove Single Air Control Regulates Heat Output and Burn TimeTwo Ways to Add Fuel Burn Only High-Quality Wood Infra-Red Reflective Glass Panels For Clear Fire ViewingAndirons Help Protect the Glass Surface Thermometer is a Valuable Guide to OperationDefiant Control Settings Use the Air Control Settings that Work Best for YouHigh-Efficiency Wood Burning With Catalytic Combustion Conditioning Your Stove Starting and Maintaining a Wood FireRefuel While the Embers Are Still Hot Add larger pieces of wood as the fire begins to burnAsh Disposal Indoor/Outdoor Location Draft ManagementSteel Chimney Flue SizingCreosote Draft TestingSingle Venting FuelNegative Pressure ConclusionMaintenance Check the Operation Primary Air Shutter How to Adjust the Door LatchesAdjust the Damper as Needed Tighten the Damper Handle as NeededRemoving and Cleaning the Combustor Inspection and CleaningWhen to Suspect a Combustor Problem Catalytic ElementRemove the bricks and the brick retainer Replace the Stove Gaskets as Needed 30001693Chimney System Annual MaintenanceAdjust the Door Latch If Necessary Permanent Defiant GasketsAppendix Catalytic Combustor Appendix Chimney and Fireplace Hazards For a fireplaceDefiant Woodburning Stove Defiant Woodburning Stove Model Shell Enamel Parts Defiant Color Warranty CFM Corporation

1945 specifications

Vermont Casting, founded in 1975, quickly established itself as a leader in the cast iron stove industry. However, the reference to 1945 in relation to Vermont Casting might allude to the beginnings of the American hearth industry post-World War II. In this pivotal period, the demand for home heating solutions soared, setting the stage for innovations in wood and gas stoves that would shape future designs.

Vermont Casting made a name for itself through a commitment to craftsmanship and durability. The company utilized high-quality cast iron, renowned for its excellent heat retention and even heating properties. This robust material allowed stoves to radiate warmth long after the fire had extinguished, making them an efficient choice for home heating.

One of the standout features of Vermont Casting stoves is their unique design which blends functionality with aesthetic appeal. The company offered both traditional and contemporary styles, appealing to a wide range of consumer tastes. With elaborate decorative patterns and a classic look, Vermont Casting stoves became a centerpiece in many homes, adding warmth not just through heat but also through design.

In terms of technology, Vermont Casting pioneered advancements in combustion efficiency. Their stoves often feature secondary combustion systems that ensure the complete burning of wood, which helps reduce smoke emissions and maximizes heat output. This not only complies with stringent environmental regulations but also makes their products eco-friendly.

Another notable characteristic of Vermont Casting stoves is their versatility. The company produces a range of models that cater to different fuels, including wood, gas, and pellets. This flexibility allows homeowners to choose the best heating solution for their specific needs and preferences.

Vermont Casting also places a strong emphasis on user comfort and ease of use. Many models come equipped with features like airwash systems for cleaner glass, lever handles for easy door operation, and ash pans for convenient cleanup. These thoughtful details enhance the overall user experience, making heating homes more efficient and enjoyable.

As the company has continued to innovate, it has remained committed to sustainability, focusing on creating products that are not only effective but also environmentally responsible. Vermont Casting's dedication to quality, technology, and design has cemented its status as a trusted name in the hearth industry, making it a preferred choice for consumers looking for both performance and style in their heating solutions.
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