What is a catalyst?

By definition, a catalyst is not consumed or used up.

The nature of a catalytic reaction is often defined as:
“A substance, usually present in small amounts related to the reactants, that modifies and especially increases the rate of a chemical reaction without being consumed in the process.”

The catalyst in a catalytic woodstove appliance is a coated ceramic honeycomb through which the exhaust gas is routed. The catalytic coating lowers the ignition temperature of the gases as they pass through. This allows catalytic woodstove appliances to operate at low firing rates while still burning cleanly.

Because the catalyst causes a restriction to gas flow through the appliance, these units always include a by-pass damper into the flue. The damper is opened when the appliance is loaded and until a hot fire is established, then it is closed, forcing the gases through the combustor for extended clean burn.

Catalytic Stove Design …

Click on the picture for a larger view























Note: It is very important to remember:

Catalytic stoves are designed to burn natural, seasoned dried wood only.

Installation of a new EPA-certified Catalytic Stove.

Improper installation of your woodstove can result in a house fire or cause greater pollution.
If a stove isn't installed properly, it can also affect the draft of the stove. Proper draft is very important in reducing pollution and maintaining high efficiency. Before having your stove installed, be sure to check with local authorities regarding building codes and permits, and notify your fire insurance company.

Below are a few tips that address the importance of proper installation:

1. By using a certified installer, they can determine the proper draft of your stove, make sure all the seals are tight, and ensure that your stove is installed with all safety measures necessary.

2. They will be able to make sure proper flue size and installation is being used.

3. They will make sure that the draft system seals are as tight as possible to prevent smoke from leaking into your house and to contribute to good draft.

Contact your local certified wood stove installer for complete details.

Again, this is very important for your safety and comfort

Understanding wood burning appliances a little better.

Definition of a Wood stove or Wood heater…
Wood heater means an enclosed, wood burning appliance capable of and intended for space heating or domestic water heating that meets all of the following criteria:

An air-to-fuel ratio in the combustion chamber averaging less than 35-to-1 as determined by the test procedure performed at an accredited laboratory, like Omni.

A usable firebox volume of less than 0.57 cubic meters (20 cubic feet);

A minimum burn rate of less than 5 kg/hr (11 lb/hr) as determined by the test procedure prescribed in §60.534 of the U.S. EPA Federal Register and performed at an accredited laboratory;

A maximum weight of 800 kg (1,760 lb). In determining the weight of an appliance for these purposes, fixtures and devices that are normally sold separately, such as flue pipe, chimney and masonry components that are not an integral part of the appliance or heat distribution ducting, shall not be included.

How can I tell if a woodstove is EPA-certified?

All certified woodstoves offered for sale will have a permanent and a temporary label indicating that the stoves are EPA-certified. The temporary label will also contain information that you will find useful when shopping for a new stove.

The label will tell you generally how clean and how efficient each woodstove is. However, because regulations require all new stoves to burn much cleaner and more efficiently than unregulated woodstoves, there should not be significant differences in efficiency and emissions performance among the certified catalytic models. This holds true for the non-catalytic models as well.

The label will also indicate which stoves are equipped with catalytic combustors.

Perhaps the most important information on the label you will need when selecting a stove is the heat output range. Use this information to help select the right size stove for the space you will be heating.

Sample temporary labels:

Why does the U.S. EPA regulate woodstoves?

Residential woodstoves are one of the nation's largest sources of particulate matter (smoke). Wood smoke also contains significant amounts of carbon monoxide, hydrocarbons, and many other organic compounds. These pollutants are known to cause respiratory and cardiovascular illness and contribute to atmospheric visibility problems and property damage. The EPA regulations require woodstove manufacturers to produce stoves that emit less pollution.
As consumers replace their older woodstoves with cleaner, more efficient, new stoves, the quality of the air will improve, particularly in residential neighborhoods where wood burning stoves are popular.

Click on the picture for a larger view

Be sure and ask your local stove dealer about the high efficient, clean burning catalytic stoves and watch for my future articles on "Buying an EPA-Certified Woodstove"

Why catalytic stoves are required to have lower emission limits?

It is best stated in the 1988 September issue, of one of the industry's leading magazines and I quote word for word from the article:

The article reads:
The EPA is on record stating catalytics represent the "best demonstrated technology" the industry has today. In other words, it's the federal agency's policy that combustors are the best solution to the wood smoke problem.
The EPA points to the following factors:
-More than 60 manufacturers use combustors in their stove designs.
-Catalytics deteriorate, but the EPA figures consumers can expect to squeeze more than 10,000 hours out of the combustor.
The deterioration of combustors is an improvement point, because the agency compared the lifetime performance of catalyst and non-catalyst units.
They note that catalytics burn cleaner than non-cats during a stove’s early years.
However, the emissions put out by a catalytic stove increases as the combustor ages. Both types of units burn about as clean, when averaged over the lifetime of the stoves, according to the EPA.
(end of article)

This is why the EPA's Phase I and Phase II emission limits, on wood burning stoves, are set the way they are.
However, catalytic stove technology has came a long way since this article was written.
Catalytic stove designs have changed since 1988. The catalytic combustor is now well protected from firebox flames in all catalytic stove models.

I would like to add this comment:
I have talked to consumers over the years, that had catalytic units that held up for 10 to 15 years and were still working on the day they called me.
Easy to see why FIRECAT combustors are offered to consumers with a 6 year prorated warranty from the date they buy a new catalytic stove.

A few more related comments:
1. FIRECAT catalytic combustors are made of high temperature, honeycomb ceramic and will take up to 2400 degrees F. before they reach, what I call a glazing point. Naturally, the stove will never reach this kind of operating temperature to destroy the combustor. They are durable and hold up well under proper operating methods.
Flame impingement and thermal shock, not normal operating methods, can be another story altogether. This will be addressed at a later date.

2. FIRECAT combustors are coated with noble metals that act as the catalyst. They never go away or wear out. Only ageing, abuse or improper operating of the stove will stop them from doing their job.

3. FIRECAT combustors can save the stove owner a lot of money over the years.
Consider fuel costs alone. (as much as 1 less cord out of every 3)
By burning low, they will save on fuel costs and best of all with no sacrifice of BTU output.
The FIRECAT combustor will produce temperatures that are at least twice that of the firebox. Therefore, they don't need high flames in the firebox to produce heat to keep warm.
Check out the catalytic stove's efficiency and do some comparing.

Standards for particulate matter emissions under the EPA’s Phase II Program

Unless exempted under §60.530 of the U.S. EPA Federal Register, each wood burning appliance manufactured on or after July 1, 1990, or sold at retail on or after July 1, 1992, shall comply with the following particulate matter emission limits as determined by the test methods and procedures in §60.534 of the U.S. EPA Federal Register:

A wood burning stove equipped with a catalytic combustor shall not discharge into the atmosphere any gases which contain particulate matter in excess of a weighted average of 4.1 g/hr (0.009 lb/hr).

A wood burning stove not equipped with a catalytic combustor shall not discharge into the atmosphere any gases which contain particulate matter in excess of a weighted average of 7.5 g/hr or (0.017 lb/hr).

Wood burning appliances exempt from EPA certification 2012

(Subject to future changes)
1. Stoves built by U.S. manufacturers for export and not sold in the United States.
2. Boilers. (Certification program to start in March of 2008)
3. Furnaces.
4. Cook stoves.
5. Stoves for coal burning only.
6. A wood heater built for research and development purposes.
(No to be sold and no more than 50 per model)


Definitions of appliances exempt from EPA certification…

Boiler…Boiler means a solid fuel burning appliance used primarily for heating spaces, other than the space where the appliance is located, by the distribution through pipes of a gas or fluid heated in the appliance. The appliance must be tested and listed as a boiler under accepted American or Canadian safety testing codes. A manufacturer may request an exemption in writing from the Administrator by stating why the testing and listing requirement is not practicable and by demonstrating that his appliance is otherwise a boiler.

Furnaces… Furnace means a solid fuel burning appliance that is designed to be located outside of ordinary living areas and that warms spaces other than the space where the appliance is located, by the distribution of air heated in the appliance through ducts. The appliance must be tested and listed as a furnace under accepted American or Canadian safety testing codes unless exempted from this provision by the Administrator. A manufacturer may request an exemption in writing from the Administrator by stating why the testing and listing requirement is not practicable and by demonstrating that his appliance is otherwise a furnace.

Cook stoves… Cook stove means a wood-fired appliance that is designed primarily for cooking food and that has the following characteristics:
(1) An oven, with a volume of 0.028 cubic meters (1 cubic foot) or greater, and an oven rack,
(2) A device for measuring oven temperatures,
(3) A flame path that is routed around the oven,
(4) A shaker grate,
(5) An ash pan,
(6) An ash clean-out door below the oven, and
(7) The absence of a fan or heat channels to dissipate heat from the appliance.

Coal burning heater… Coal-only heater means an enclosed, coal-burning appliance capable of space heating, or domestic water heating, which has all of the following characteristics:
(1) An opening for emptying ash that is located near the bottom or the side of the appliance,
(2) A system that admits air primarily up and through the fuel bed,
(3) A grate or other similar device for shaking or disturbing the fuel bed or power-driven mechanical stoker,
(4) Installation instructions that state that the use of wood in the stove, except for coal ignition purposes, is prohibited by law, and
(5) The model is listed by a nationally recognized safety-testing laboratory for use of coal only, except for coal ignition purposes.

What are the advantages of using a catalytic wood?

An EPA Phase II
catalytic wood burning stove delivers 72% or better heating efficiency.
This means that 72% of the energy available in wood is delivered into the
surrounding living area.
In addition to the 72% heating efficiency, the catalytic wood burning
stoves of today:
1. Reduce air pollution by up to 90%.
2. Reduce creosote build-up. (Up to 90% reduction)
3. Generate up to 50% more useful heat from each log.
4. Generate longer burns per load.
5. Saves the consumer up to 1/3 on fuel cost. (One less cord out of every 3)

EPA Stove Phases defined:
Pre-Phase I stoves…These stoves could not be manufactured
after June 30, 1988.
However, stoves could be sold at retail level for two more years.
Phase I program…. went into effect on July 1, 1988 and was effective through
June 30, 1990.
Manufacturers could not build stoves after this dead-line.
Again, these stoves could be sold at retail level for two more years.
Phase II program… went into effect on July 1, 1990 and is effective still
today.
Manufacturers must re-certified all models every 5 years under the Phase II
program.

A New Era for the wood burning stoves

In the early 1980’s, it was reported, better than 500 manufacturers were building wood burning stoves. Many were just one man operations, designing and building their stoves in the garages of their homes.
However, it wasn’t long before the Oregon DEQ and US EPA put a halt to just anyone building and selling wood burning stoves. New regulations, standards, and certification programs forced many of the smaller companies out of this type business. This was mainly because they could not meet the new regulations or could not afford the expense to comply. On the other hand, the larger stove manufacturers could afford the expense to comply and remained in business.
It was at this point in time, catalytic combustors played a major role in the survival of many stove manufacturers.

In 1988 one of the industry magazines published an article entitled “A NEW SEASON FOR WOODSTOVES”. Another article written by the US EPA entitled “EPA and You” talked favorably about catalytic combustors and stated, “Expect to see many more of these types of wood burning appliances in coming years”.

Another article published in the September issue, reported more than 120 wood burning stoves had been EPA certified and nearly two-thirds were catalytic units.
By the end of 1989, there were nearly 80 woodstove manufacturers certified to at least the EPA’s Phase I emissions program and 60% of these manufacturers had certified with catalytic wood burning appliances. Some of their catalytic models had emission ratings as low as 1.0 gph and 72% efficiency. The catalytic models had less fuel consumption and creosote reduction of up to 90%.
After June 30, 1990 stove manufacturers could no longer build the Phase I stoves and now had to build stoves to meet the EPA’s Phase II program.
Six months after the Phase II certification went into effect, roughly 70 woodstove manufacturers were already certified to the Phase II program.
Of these 70 stove manufacturers, 41 were certified with catalytic models. This was 58.6% of the stove manufacturers to this point in time. The 1990’s proved to be a super sales year for the manufacturers building catalytic stoves and the dealers selling them.
Throughout the decade magazines published articles about catalytic stoves and the catalytic combustors in them. Articles like, “Keeping Cats Purring”
Articles from dealers and chimney sweeps stating “it is important to remember, that people who buy catalytic products are generally those who are interested in the best possible performance and have greater heating needs” and a chimney sweep in the state of Washington saying, “In general, cats three to five years old are holding up well” and another sweep in North Carolina stating, “He hasn’t had a service call for a combustor during the two years he’s been servicing and selling EPA approved catalytic stoves”.
The catalytic wood burning appliances had established a place in the industry and in the hearts of the consumers using them.

History and the role of catalytic stoves.

To best understand the role of the catalytic stove, we need to go back to the 1970’s when heating costs increased drastically.

It was reported back then … as you can see on this chart,
electric rates increased 215% in that decade,
oil prices increased 272%
and that natural gas increased 483%

To combat these cost increases, many homeowners switched to wood as a fuel for their heating needs.

After all, wood was in abundance and free in most parts of the country.
During this same period of time, hundreds of new stove companies began to spring up across the United States.
Bare in mind, there were no environmental regulations yet in place.

However, the advantages of burning wood did have some draw backs.

Early designed stoves produced…
-much wasted energy...
-harmful air pollution...
-and heavy amounts of creosote

It was in the early 1980’s that the catalytic combustor was found to be an ideal solution aimed at answering...... consumer, manufacturing and environmental problems.
When we stop and think about it, the catalytic combustor was actually a “green product before “green” became popular.

Happy New Year

Happy New Year. I sincerely hope the new year will bring you much happiness and the best of health.

This year I plan to post a little differently than I have in the past. In the past I have made random topic postings. Starting tomorrow, I will begin posting articles on understanding catalytic combustors and catalytic stoves in a manner that will allow anyone to understand catalytic combustors and catalytic wood burning appliances from scratch. In other words, if you’re thinking about buying a new catalytic appliance, you will understand why they are such a good buy and you will also understand how simple they are to operate before ever owning one.

Why am I doing this? Because I have spent 24 years working with woodstove manufacturers, independent stove testing companies and with the U.S. EPA in the wood burning stove industry. I have spent the same period of time working with consumers, dealers and distributors as a sales engineer for Applied Ceramics Inc., the leading manufacturer of catalytic combustors for wood burning appliances. I am retired now and want to continue educating people on what I feel is the best heating value for their money. I too am a consumer and I want the truth when buying a product. I want the same for you and I have no reason to feed you false information, just the facts.

Please stay with me through the year as I post step by step articles every three days on understand everything you should know about catalytic wood burning.

Sincerely,
Tim Cork