Friday, December 15, 2017

What Happens When Wood Burns? Article 2 of 3

This is the second of three articles on the above subject.

1. Evaporation of water  Posted 12/12/17

2. The emission of smoke

3. The charcoal phase  To be posted1 2/19/17

The emission of smoke:
As the wood heats up above the boiling point of water, it starts to smoke. The smoke is visible result of the decomposition of the solid wood as it vaporizes into a cloud of combustible gases and tar droplets.

The smoke will burn if the temperature is high enough and oxygen is present. When the smoke burns, it produces the bright red flames that are characteristic of wood combustion.

If smoke does not burn in the firebox, it will exit the appliance and into the chimney where it will either condense forming creosote deposits or be expelled as air pollution. Unburned smoke represents an efficiency loss because it contains a large part of the total energy in the wood.

However, catalytic stoves with the use of a catalytic combustor, burns this smoke before it is expelled as air pollution and burns it as a fuel to produce heat that can be 2-3 times hotter than the firebox temperature. This also gives a higher efficiency out of the stove.

At the same time, the catalytic combustor will burn up to 90% of the creosote contained in the smoke.

Tuesday, December 12, 2017

What Happens When Wood Burns? Article 1 of 3

This is the first of three articles that I will be posting on the above subject.

1. Evaporation of water

2. The emission of smoke  (To be posted on 12/15/17)

3. The charcoal phase  (To be posted on 12/19/17)

Evaporation of water:
Up to half the weight of a freshly cut log is water. After proper seasoning the water content is reduced to about 20 percent. As the wood is heated in the firebox, this water boils off, consuming heat energy in the process. The wetter the wood, the more heat energy is consumed.

That is why wet firewood hisses and sizzles and is hard to burn, while properly seasoned wood ignites and burns easily.

Re-fueling with wet or unseasoned wood in a catalytic stove will send moist smoke to the catalytic combustor and cause the combustor to stop working. It will cause the stove to struggle and not operate properly. In addition re-fueling with wet or unseasoned wood and operating the stove with the by-pass closed, can cause damage to the catalytic combustor.

Friday, December 8, 2017

Reasons for smoke spillage.

A survey of households that use wood for heating showed that a large majority of users had experienced smoke spillage at least once. Smoke spillage can be reduced or eliminated through good system design and proper appliance operation.
The smell of wood smoke can be pleasant to some, but inside your home it’s a sign that the wood burning system is not functioning properly. The smoke contains harmful air pollutants which can be irritating or even dangerous in high concentrations. Properly designed, installed and operated wood burning systems do not spill smoke into the house.

There are three main reasons why some wood burning systems smoke:
1. Bad system design: There are design characteristics that can make a wood burning system more likely to spill smoke. Most of these characteristics result in low flue temperature and low draft. Outside wall chimneys and long flue assemblies before exhaust reach the chimney are just a couple.
2. Extreme negative pressure in the house: Energy efficiency practice and new building code rules are making our houses more and more air tight. This makes the house energy efficient, but also makes them sensitive to depressurization when air is exhausted from the house. Other exhaust appliances used in the house can cause extreme negative pressure in the house when they are operating.
3. Improper woodstove firing technique: When a wood fire is starved for air it smolders, producing a relatively cool, smoky fire. The temperatures throughout the system are low. During a smoldering fire, the chimney will not be receiving the hot gas it needs to produce strong draft.

And remember, when refueling first open the by-pass before opening the firebox door.

Tuesday, December 5, 2017

How to rekindle a fire from hot coals

To rekindle a fire from hot coals, rake the charcoal towards the front of the firebox where the combustion air enters. Place the pieces of wood on and behind the coals. Open the air intakes fully and leave them open until the pieces of wood are well-charred.

This illustration shows the arrangement of logs for an extended fire.

Allow the fire to burn with bright turbulent flames until the wood is burning well. This should take about 20 to 30 minutes, depending on the size of the pieces and the moisture content of the wood. If the appliance is catalytic, this will also be ample time for the catalytic combustor to light-off. Now the by-pass can be closed and the air intakes regulated for a nice even burning fire.

Be sure to read the stove's operating manual for complete instructions.

Friday, December 1, 2017

Techniques on Fueling

Techniques for fueling may vary, but shown below are the two most common.

Small pieces of wood arranged loosely in a crisscross pattern burn quickly because the combustion air can reach all pieces at once.

Larger pieces placed compactly burn slowly because there are fewer spaces where the air can penetrate the load.

Never add just one or two pieces of wood to a fire.  Three or more pieces are needed to form a sheltered pocket of glowing coals that reflect heat toward each other and sustain the fire.


Tuesday, November 28, 2017

What makes the FIRECAT combustor so great?

Over the years, I have talked to thousands of consumers that have had FIRECAT catalytic combustors lasting for up to 10 years or more and the units 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 appliance.

Here's why it's such a great product:

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 in later postings.

 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. In other words, the catalytic combustor is your heat source.

When looking to buy a new wood burning stove, check out the catalytic stove's for their efficiency and do some comparing before you buy.

Friday, November 24, 2017

Methods of cleaning the catalytic combustor.

If it becomes necessary to clean the combustor, below are three recommended methods.

Normally the catalytic combustor requires little or no maintenance because it generates such high temperatures, it is basically self-cleaning. However, should the combustor become masked with soot or creosote, it is possible to burn the accumulation off by opening the bypass and building a hot fire. Once the hot fire is created, close the bypass halfway and burn for 30 to 60 minutes with the bypass left in this position.

Never use cleaning solvents to clean the combustor. It would be wise to check and clean the combustor, if necessary, before each burning season and inspect the flue system for any signs of creosote buildup.

A clean flue helps prevent chimney flue fires.

Thursday, November 23, 2017

Tuesday, November 21, 2017

Here's the proven facts.


Today’s catalytic wood burning

appliances deliver 72% or better

heating efficiency.

This means that 72% of the energy

available in the wood is delivered to

the surrounding living area.
In addition to the 72% heating

efficiency, catalytic wood burning

appliances built today will…

- they reduce air pollution by up to


- they reduce creosote build-up. (up to

90% reduction)

- they generate up to 50% more useful

heat from each log.

(this means longer burns per load)

- and they save the consumer up to

1/3 on their fuel cost.
(that's one less cord out of every



It is important to keep the catalytic

combustor in top working condition

for the best efficiency of your wood

burning appliance.

Friday, November 17, 2017

Close-up of the Firecat catalytic combustor.

Please read and understand how it works in your appliance.

Tuesday, November 14, 2017

Learn all you can about your catalytic appliance and its component parts.

Learn and understand the catalytic wood burning appliance and its component parts and what they do as well.

Note that only the bypass damper and the adjustable primary air intake will require adjustments during operation of the stove.

Friday, November 10, 2017

Helpful hints for a healthy combustor in your wood burning appliance.


Never burn foreign matter such as…


painted wood,

large amounts of colored paper,




paneling with glue,

oily products and so on.

Burning these materials will gradually reduce the efficiency of the catalyst.

“Burn only seasoned dried wood”

All catalytic combustors used in EPA certified Phase II stoves have a life expectancy of at least, 10,000 burning hours, when used according to the stove's operating manual. It could be said, that a catalytic combustor’s life is really based on a number of things....

-Operating the stove properly.... (Not burning with firebox door open or perhaps closing the by-pass to soon)

-Proper maintenance habits to both stove and combustor... (Simple things like checking the firebox door gasket)

-Burning proper fuel in the appliance, (This means burning seasoned dried wood only- no foreign matter that could poison the combustor)

-Using a Certified Phase II stove for home heating and not an older stove design. (most stoves built today are designed well and protect the combustor from the firebox flames, the older pre-phase I stoves didn't)

Tuesday, November 7, 2017

What to do when the combustor is not working properly …

-Check your fuel supply for moisture content. Fuel should be seasoned dried wood. Rain and snow are considered moisture and will produce damp smoke and steam. Both harmful to your combustor, especially when refueling and the combustor is burning hot.

 -Check the flue and chimney, making sure the stove’s exhaust system is not blocked nor has any obstructions.

-Make sure the stove is getting the proper draft.

-Check all movable stove parts to be sure they are working freely.

-Make sure the combustor has not fallen out of its holding device.

-Check the combustor for plugged cells. Follow cleaning instructions.

-Check if the combustor has been in the stove for more than six burning seasons, it might be time to replace it.

Be sure to follow the manufacturer’s instructions for proper firing. Different manufacturers and stove models require different procedures.

As a rule of thumb, the catalytic combustor needs a minimum of 500 F. temperature focused on it for a period of 20 to 30 minutes to achieve light-off.  This is done with the bypass in the open position.

Nothing but heat will be going to the combustor at this stage. The catalyst will receive the heat it needs in this period of time.