Catalytic 

Wood-Burning 

Technology

Presented By:
Agenda

 Catalytic Combustors in Wood Stoves

 Historical Look

 How Catalytic Combustors Function

 Catalytic Stove Operation

 Catalytic Combustor

 EPA Requirements

 Education, Facts and Fiction

 Warranty

 Efficiencies and Clean Burning

 Home Heating Comparison
Agenda

 Catalytic Combustors in Wood Stoves

 Historical Look

 How Catalytic Combustors Function

 Catalytic Stove Operation

 Catalytic Combustor

 EPA Requirements

 Education, Facts and Fiction

 Warranty

 Efficiencies and Clean Burning

 Home Heating Comparison
Environmental Evolution

Woodstove & Fireplace Inserts:

 ~1978 – First wood stoves manufactured with a 

catalytic combustor

 1980 - Emissions of 40 to 60 grams per hour of 

particulate matter(PM) per hour

 1985 – EPA emission standards 

 Regulatory negotiations

 1988 – Phase I – 5.5 grams PM per hour 

 New mfg – July 1988

 1990 – Phase II – 4.1 grams PM per hour 

 New mfg – July 1990 All sales – July 1992

 2009 – EPA Re-Opens NSPS Regulations on woodburning appliances for revision
Agenda

 Catalytic Combustors in Wood Stoves

 Historical Look

 How Catalytic Combustors Function

 Catalytic Stove Operation

 Catalytic Combustor

 EPA Requirements

 Education, Facts and Fiction

 Warranty

 Efficiencies and Clean Burning

 Home Heating Comparison
What Is Catalyst

 Definition: A catalyst is a substance which lowers the 

activation energy for a given reaction, without being 

consumed by the reaction.

 To oxidize organic 

compounds, HEAT is the 

activation energy 

necessary to complete the 

reaction.
Combustion Reaction

 Catalysts create a Combustion Reaction

 Also Referred to As “Oxidation”Reaction

 Carbon in any compound Combines with Oxygen to 

form Carbon Dioxide and Water

 2 CO + O2  2 CO2

 C3H8 + 5 O2  3 CO2 + 4 H2O
VOC Destruction

VOC – Volatile Organic Compounds
Combustor Components

 Carrier-physical supports for active metal catalyst

 Catalyst Coatings –Precious 

(noble) metals or base 

metal elements which are 

“active in the combustion 

reaction”. Some catalyst 

manufactures also use a 

pre-coating, also known as a 

washcoat.
Cell Density

CPSI- cell opening per square in of ceramic
The Catalytic Stove 

Evaluating a Catalyst Wood Stove

 Catalytic Stove design
The Catalytic Stove 

 A combustor-equipped stove operates like any other –

only more efficient

 You load it, light it, and adjust it to maintain it just as you 

would any wood stove
The Catalytic Stove 

What to Watch

 Achieving Catalytic Light-Off

 Maintaining Catalytic Burning Conditions

 Recommended Fuels

 Understanding Stove Limitation

Visit the CHC website for Detailed Instructions.

www.chc-hpba.org
Maintaining Catalytic Burn Conditions

 During start-up a medium to high fire rate must be 

maintained for ~20 minutes with bypass open

 During refueling, fire the stove for ~10 minutes to 

ensure proper temperatures for catalytic activity to 

continue with bypass open

Visit the CHC website for Complete instructions.

www.chc-hpba.org

The Catalytic Stove 
Importance of the Firing Procedure

 Keep a healthy combustor

 Prevent plugging

 Prevent peeling of the coating

 Prevent thermal cracking

 Prevent deactivation

The Catalytic Stove 
Troubleshooting

Damage Prevention

 DO NOT:

 Drop combustor

 Run water through the combustor

 Remove the metal band from the combustor

 Remove combustor from manufacturer's holder

 Scrape the inside walls of the combustor

 Use compressed air to clean the combustor

Visit the CHC website for Advice.

www.chc-hpba.org
Care Guidelines 

Cleaning Procedures

 “Hot” Fire Cleaning 

 Minor Cleaning Procedure

 Major Cleaning Procedure

Visit the CHC website for Complete Instructions.

www.chc-hpba.org
Agenda

 Catalytic Combustors in Wood Stoves

 Historical Look

 How Catalytic Combustors Function

 Catalytic Stove Operation

 Catalytic Combustor

 EPA Requirements

 Education, Facts and Fiction

 Warranty

 Efficiencies and Clean Burning

 Home Heating Comparison
Environmental Evolution

Woodstove & Fireplace Inserts:

Current Standards:

“Questionable” Durability of the catalyst was cited as 

the reason for 2 Standards.

Type of Device Washington State Limit EPA Limit

Catalytic Wood Burning Device 2.5 grams per hour 4.1 grams per hour

Non-Catalytic Wood Burning 

Device

4.5 grams per hour 7.5 grams per hour
Environmental Evolution

Woodstove & Fireplace Inserts:

Current Standards:

All catalyst used in an approved EPA wood-burning 

appliance must receive approval from EPA. 

Test result cannot show an increase from the 

appliances certified emission rating of more than 2.5 

g/hr of particulate matter to demonstrate catalyst 

equivalency.
Agenda

 Catalytic Combustors in Wood Stoves

 Historical Look

 How Catalytic Combustors Function

 Catalytic Stove Operation

 Catalytic Combustor

 EPA Requirements

 Education, Facts and Fiction

 Warranty

 Efficiencies and Clean Burning

 Home Heating Comparison
Life of a Combustor

 The anticipate operational life is 12,000 to 50,000 hours.

 Confirmation Studies were performed independently by 

Omni Environmental Laboratories 

 The Omni aging study conducted in December of 2009 

showed limited reduction in activity after multiple seasons 

of use

 Study Parameters

 Results
Results - Stove A

Owner / 

Combustor 

Informatio

n

Fuel Usage

(Cords/Year)

Reduction of 

Particulate Matter

(5H Adjusted (g/hr))

Reduction of 

Carbon 

Monoxide 

(g/hr)

Reduction of 

VOC as 

Carbon 

(g/hr)

New1 n/a 85% 98% 83%

Used 

(5.75 Years)

3 83% 91% 56%

Used 

(8.5 Years)

More than 2 81% 96% 64%

1Aged based on EPA Method 28 Guidelines

Owner / Combustor 

Information

Particulate Matter

(5H Adjusted (g/hr))

Carbon 

Monoxide 

(g/hr)

VOC as 

Carbon (g/hr)

Blank (No Catalyst Coating) 7.80 279.11 23.58

Effects of Catalyst in Stove A
Results - Stove B

Owner / 

Combustor 

Informatio

n

Fuel Usage

(Cords/Year)

Reduction of 

Particulate Matter

(5H Adjusted (g/hr))

Reduction of 

Carbon 

Monoxide 

(g/hr)

Reduction of 

VOC as 

Carbon 

(g/hr)

New1 n/a 83% 93% 74%

Used 

(5.5 Years)

4 to 6 78% 74% 45%

Used 

(9 Years)

3 80% 89% 56%

1Aged based on EPA Method 28 Guidelines

Owner / Combustor 

Information

Particulate Matter

(5H Adjusted (g/hr))

Carbon 

Monoxide 

(g/hr)

VOC as 

Carbon (g/hr)

Blank (No Catalyst Coating) 31.95 335.64 39.45

Effects of Catalyst in Stove B
Results – Summary

1Aged based on EPA Method 28 Guidelines

Stove A New1 Used 

5.75 Years

Used 

8.5 Years

Particulate Matter

(5H Adjusted (g/hr))

85% 

Reduced Emissions

0.14 g/hr Increase from 

New

0.3 g/hr Increase 

from New

Change of Particulate Emission in an Aged Combustor

Stove B New1 Used 

5.75 Years

Used 

8.5 Years

Particulate Matter

(5H Adjusted (g/hr))

83% 

Reduced Emissions

1.9 g/hr Increase from 

New

1.04 g/hr Increase 

from New

Less Than 1 g/hr Average Change in Emissions After 9 Years
Regulations Revisited:

Current Standards:

With An Increase of ~1 g/hr over 9 Years 

A Washington State Approved Catalytic Stove will not reach the 

same emission levels as a Washington State Non-Cat Stove for 

18 Years.

An EPA Approved Catalytic Stove will not reach the same emission 

levels as a Washington State Non-Cat Stove for 30.6 Years

Using the original NSPS Logic of Course

Type of Device Washington State Limit EPA Limit

Catalytic Wood Burning Device 2.5 grams per hour 4.1 grams per hour

Non-Catalytic Wood Burning 

Device

4.5 grams per hour 7.5 grams per hour
Combustor Condition

 Stove A

Blank 

(No Coatings

New 

(Aged 50+ Hours)

Used 5.75 Years

3 Cords Per Year

Used 8 Years

More Than 2 Cords /Year

All combustors pictured post vacuuming
Combustor Condition

 Stove b

Blank 

(No Coatings

New 

(Aged 50+ Hours)

Used 5.75 Years

3 Cords Per Year

Used 8 Years

More Than 2 Cords /Year

All combustors pictured post vacuuming
Agenda

 Catalytic Combustors in Wood Stoves

 Historical Look

 How Catalytic Combustors Function

 Catalytic Stove Operation

 Catalytic Combustor

 EPA Requirements

 Education, Facts and Fiction

 Warranty

 Efficiencies and Clean Burning

 Home Heating Comparison
Combustor Warranty

 EPA requires each stove and/or catalyst manufacturer 

provide a 6-year pro-rated warranty on original combustors

0.4% of OEM Combustors are replaced in the first 3 years of 

Service (most failures involve over temperature conditions)

Less Than 10% of all OEM Combustors are replaced during the 

EPA Mandated 6 Year Warranty Period

Contact your stove manufacture for more details.
Agenda

 Catalytic Combustors in Wood Stoves

 Historical Look

 How Catalytic Combustors Function

 Catalytic Stove Operation

 Catalytic Combustor

 EPA Requirements

 Education, Facts and Fiction

 Warranty

 Efficiencies and Clean Burning

 Home heating Comparison
Efficiencies:

Where Catalytic Wood Stoves Excel 

 Any Time:

 Uninterrupted continuous low burns are needed

 Infrequent fuel loads are made

 Consumer is an efficiency nut and drives a Prius TM
Efficiencies:

Where Catalytic Wood Stoves Excel 

Example Scenario:

 Let's assume for a moment there are two homes,

located next to one another in the same community 

in a suburb.

 Both Homes Have:

 The same number of occupants 

 Exact same floor plan 

 Same desired indoor temperature during a cold winter day.
Efficiencies:

Where Catalytic Wood Stoves Excel 

Example Scenario:

 Both homeowners also purchase their winter fuel from the 

same supplier on the same day from the same pile of 

cordwood.

 Both homeowners also expect their wood stove to be 

their main source of heat in their homes.
Efficiencies:

Where Catalytic Wood Stoves Excel 

Example Scenario:

Home 1:

A non-catalytic wood stove that is Washington State 

approved at a maximum 4.5 grams/hour and 75% 

efficiency. 

Home 2:

A catalytic stove rated at 1.76 grams/hour and with an 

efficiency rating of 82.5%.
Efficiencies:

Where Catalytic Wood Stoves Excel 

Example Scenario:

It is obvious the catalytic model in Home 2 is much cleaner 

burning overall and is also much cleaner burning as 

discussed earlier, in the low & medium burn settings. The 

catalytic wood stove will therefore produce fewer 

emissions over the winter, but how much less?
Efficiencies:

Where Catalytic Wood Stoves Excel 

Example Scenario:

 To reach the actual answer and to have a total appreciation 

for the very nature of efficient, catalytic wood stoves, look at 

each of the stoves' individual efficiencies.

EFFICIENT

 a. Acting or producing effectively with a minimum of waste, 

expense, or unnecessary effort.

 b. Exhibiting a high ratio of output to input.
Efficiencies:

Where Catalytic Wood Stoves Excel 

Example Scenario:

 There is a 7% difference in efficiency between the 

Appliance in Home 1 vs. Home 2.

 Home 1 with the non-catalytic wood stove will actually 

burn more wood and produce even greater levels of 

particulate over the same winter.

 It isn't enough to just look at grams of particulate 

produced each hour without taking into consideration 

overall efficiency
How Are Stoves Used

COMPARE

PM (g/hr)

(Particulate Matter)

Stoves spend 80% of their 

life in this range

Low Medium Medium High High

Burn Rate (kg/hr) <0.8 0.8 to 1.25 1.25 to 1.9 MAX (3 to 5)

Heat Output (BTU/hr) <10,000 ~12,000 ~15,000 ~40,000+

AVG Washington State 

Certified NON-CAT Stove

3.45 3.85 3.05 2.70

AVG Washington State 

Certified CAT Stove

0.29 0.83 1.24 4.67
On Behalf of the 

Catalytic Hearth Coalition

Thank You !

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