1. Comparison of Phase II EPA Certified Stoves to Low Mass and Masonry Fireplaces
Dan Henry

2. EPA Phase II Certified Controlled Combustion
HEATED CON-VECTION AIR
BAFFLE INSULATION
EXHAUST
BAFFLE
SECONDARY AIR
FIREBRICK
PRIMARY AIR
CONVECTION AIR
AIR CONTROLS
AIRWASH AIR
INCOMING CON-VECTION AIR
ASH PAN ACCESS

3. EPA Phase II Certified Controlled Combustion
Stack Flow Rate
High Burn under 20 cu. ft/ min
Air Limited, Controlled Combustion
Air to Fuel ratios :1
High Firebox Temperatures
Helps to Initiate and Sustain Secondary Combustion
Limited Firebox Volume
1 - 5 Cu. Ft.
Woodstoves are Heating Appliances
Less Frequent Fueling with Full Firebox Loads
Typically 24/7 Burning Cycle
Frequent to Constant Use during Heating Season

4. Low Mass Open Burning Fireplace
DAMPER
SMOKE SHELF
AIR SPACE
UNCONTROLLED AIR FLOW
FIREBRICK PANELS
GRATE

5. Masonry Open Burning Fireplace
SMOKE SHELF
DAMPER
LINTEL
UNCONTROLLED AIR FLOW
FIREBRICK
HEARTH
HEARTH EXTENSION
ASH CLEANOUT

6. Open Burning Fireplace - Masonry or Low Mass
High Stack Flow Rate
Can be in Excess of 200 cu. ft/ min
Free Air Flow, Uncontrolled Air Flow Paths
Air to Fuel Ratios above :1
Relatively Low Firebox Temperatures
Almost Impossible to Initiate and Sustain Controlled Secondary Combustion
Large Firebox Volume
Often > 10 Cu. Ft.
Fireplaces are Aesthetic Devices
Small Fuel Load Relative to Firebox Volume
More Frequent Fueling with One or Two Fuel Pieces Added
Infrequent Use Pattern (Ave days per year)
Typically 3 – 4 Hour Burn Cycle

7. EPA Phase II Certified Controlled Combustion
Open Burning Fireplace - Masonry or Low Mass
Stack Flow Rate
High Burn under 20 cu. ft/ min
Can be in Excess of 200 cu. ft/ min
Air Limited, Controlled Combustion
Air to Fuel Ratios Typically :1
Air to Fuel Ratios Typically above :1
Firebox Temperatures
High to Initiate and Sustain Controlled Secondary Combustion
Below Levels to Initiate and Sustain Controlled Secondary Combustion
Firebox Volume
1 - 5 Cu. Ft.
Often > 10 Cu. Ft.
Appliance Use and Fueling Characteristics
Heating Appliances:
Less Frequent Fueling with Full Firebox Loads
Little or no User Interaction Between Loads
Aesthetic Devices: Small Fuel Loads More Frequent Fueling Frequent User Interaction (Poking)
Burn Duration
Typically a 24/7 Burn Cycle
Typically a 3 to 4 Hour Burn Cycle
Use Patterns
Frequent to Constant during Heating Season
Infrequent Use
Average in Range of 3 – 10 days per year

8. Open Burning Fireplace - Masonry or Low Mass
Design Challenges to Obtain Particulate Emission Improvement in Fireplaces
Reduce Excess Air
Control Air Flow Paths
Increase Firebox Temperatures
Prevent Smoke Spillage from Front of Open Fireplace
Maintain User Expectations for Open Fire
Invisible Technology from Consumer’s Viewpoint
Minimize Incremental Cost Increase to Preserve Sales Opportunities.