Osburn Matrix Wood-Burning Fireplace Insert
Osburn Matrix Wood Insert OB02028 – 75,000 BTU Wood-Burning Fireplace Insert with Blower
The Osburn Matrix Wood Insert OB02028 is a non-catalytic wood-burning fireplace insert designed for residential zone heating. It offers a manufacturer-recommended heating area of 500 to 2,100 sq. ft., a maximum heat output of 75,000 BTU/h, a 2.4 cu. ft. firebox, up to 8 hours of maximum burn time, and an included 90 CFM blower.
Model
OB02028
Fuel Type
Dry Cordwood
Heating Area
500–2,100 sq. ft.
Max Output
75,000 BTU/h
Firebox
2.4 cu. ft.
Max Burn Time
8 Hours
Max Log Length
20"
Blower
Included, 90 CFM
Important Installation Notice
The Osburn Matrix OB02028 is designed for installation in a suitable masonry fireplace and must be connected to an approved chimney-liner system. It is not approved for mobile-home or manufactured-home installation.
High-Performance Non-Catalytic Wood Heating
The Matrix is designed for homeowners who want to convert an appropriate existing masonry fireplace into an efficient wood-burning zone-heating appliance.
Its non-catalytic combustion system uses a C-Cast baffle, stainless-steel secondary-air tubes, refractory-lined firebox, and ceramic-glass door to support clean combustion and practical residential heating.
The included 90 CFM blower increases airflow through the insert's heat exchanger and helps distribute warm air into the room.
EPA 2020 compliant: The Matrix OB02028 has a documented average particulate emissions rate of 1.54 g/h.
Osburn Matrix OB02028 at a Glance
Product Type
Wood-Burning Fireplace Insert
Heating Area
500–2,100 sq. ft.
Maximum Output
75,000 BTU/h
Firebox Volume
2.4 cu. ft.
Maximum Burn Time
8 Hours
Blower
Included, up to 90 CFM
Is the Osburn Matrix OB02028 Right for Your Fireplace?
Best For
- Existing masonry fireplaces suitable for a wood insert.
- Homes requiring zone heating across 500–2,100 sq. ft.
- Buyers wanting non-catalytic combustion.
- Installations using a proper stainless-steel chimney liner.
- Homeowners wanting an included 90 CFM blower.
- Buyers wanting a ceramic-glass viewing door and air-wash system.
- EPA 2020-compliant cordwood-burning applications.
Consider Another Product If
- You need a mobile-home-approved insert.
- Your masonry fireplace does not meet the minimum opening dimensions.
- Your chimney cannot support the required liner system.
- You cannot meet required combustible clearances.
- You cannot provide the required hearth or floor protection.
- You need a freestanding wood stove rather than a fireplace insert.
Heating Performance & Efficiency
The manufacturer-recommended heating range is 500 to 2,100 sq. ft., although actual performance depends on home layout, insulation, climate, chimney draft, wood quality, and other heat-loss factors.
| Maximum Heat Output |
75,000 BTU/h (22.0 kW) |
| Tested Overall Heat Output Rate |
14,800–28,600 BTU/h (4.34–8.38 kW) |
| Average Overall Efficiency |
69% HHV / 74% LHV |
| Optimum Overall Efficiency |
77% |
| Average Particulate Emissions |
1.54 g/h |
| Average CO |
89.4 g/h |
| Maximum Burn Time |
8 Hours |
Efficiency distinction: HHV, LHV, and optimum efficiency are different measurement methods and should not be treated as one interchangeable efficiency figure.
Designed for Zone Heating
The Osburn Matrix is intended as a space heater for zone heating. It primarily heats the room where it is installed, with heat extending into connected areas to a lesser degree.
Performance varies based on home size, layout, climate, fuel quality, fireplace location, chimney draft, and other heat-loss conditions.
Heating strategy: The manufacturer's manual recommends maintaining an alternative conventional heating source in the home rather than assuming the insert will serve as the sole heating source in every installation.
Key Features
Non-Catalytic Combustion
Uses secondary combustion without a catalytic combustor.
75,000 BTU Maximum Output
Maximum stated heat output when burning dry cordwood under the specified conditions.
2.4 cu. ft. Firebox
Provides capacity for substantial wood loads in a fireplace-insert format.
20" Maximum Log Length
Supports east-west loading with logs up to 20 inches long.
8-Hour Maximum Burn Time
Actual burn duration varies with wood species, moisture, draft, load size, and heating demand.
90 CFM Blower
Included blower helps move heated air through the room.
Ceramic Glass
Single glass door with a cast-iron frame.
Glass Air-Wash System
Helps reduce deposits on the viewing glass during proper operation.
Secondary-Air System
Uses stainless-steel secondary-air tubes and a C-Cast baffle.
Wood Fuel Requirements
The Matrix OB02028 is designed to burn seasoned natural cordwood.
| Fuel |
Dry Cordwood |
| Maximum Log Length |
20" |
| Common Recommended Log Length |
Approximately 16" |
| Loading Orientation |
East-West |
| Recommended Moisture Content |
Approximately 15%–20% |
The manufacturer's manual states that wood in the approximately 15%–20% moisture range allows the insert to achieve its highest possible efficiency.
Do not burn prohibited materials: Garbage, plastics, treated wood, construction debris, petroleum products, unseasoned wood, and other prohibited fuels should not be burned in the appliance.
Firebox, Door & Construction
| Door Type |
Single Glass Door with Cast-Iron Frame |
| Glass Type |
Ceramic Glass |
| Glass Surface |
19 5/8" W × 11 7/8" H |
| Glass Air-Wash System |
Yes |
| Baffle Material |
C-Cast |
| Secondary-Air Tubes |
Stainless Steel |
| Firebox Lining |
Refractory Brick |
| Body Steel Thickness |
3/16" |
| Top Steel Thickness |
5/16" |
Osburn Matrix OB02028 Dimensions
Overall Insert
-
Width: 36 1/8"
-
Height: 25 1/8"
-
Depth: 23 1/8"
-
Flue Outlet: 6"
Firebox
-
Width: 21"
-
Height: 11 7/8"
-
Depth: 16 3/4"
Door Opening
-
Width: 17 1/2"
-
Height: 8 3/4"
Glass Surface
-
Width: 19 5/8"
-
Height: 11 7/8"
Minimum Masonry Fireplace Opening
Before ordering, verify that the existing masonry fireplace meets at least the manufacturer's minimum opening requirements.
| Minimum Width |
28 7/8" |
| Minimum Height |
23 3/8" |
| Minimum Depth |
19 5/8" |
Opening dimensions are only one part of compatibility. Chimney condition, liner configuration, combustible clearances, hearth protection, draft, fresh-air requirements, and final installation configuration must also be verified.
Chimney & Venting Requirements
The Matrix OB02028 must be connected to a suitable stainless-steel chimney liner according to the manufacturer instructions and applicable codes.
6" Flue Outlet
The insert uses a 6-inch flue outlet.
6" Recommended Connector
The recommended connector diameter is 6 inches.
Continuous Liner
The standard installation uses a continuous chimney liner from the insert to the top of the chimney.
Listed Liner Standards
ULC S635, CAN/ULC-S640, and UL 1777.
Minimum Venting Height
15 ft. (4.6 m) minimum total venting-system height.
Dedicated flue required: Do not connect the Matrix to a chimney flue serving another appliance.
Minimum Clearances to Combustible Materials
| Adjacent Combustible Side Wall |
16" |
| Combustible Side Surround / Mantel |
9" |
| Combustible Top Surround / Mantel Shelf |
27" |
| Minimum Ceiling Height |
84" |
Certification label priority: Information on the certification label affixed to the appliance overrides information published in manuals, catalogs, flyers, magazines, or websites.
Floor Protection Requirements
Canada
-
Front protection: 18"
-
Side protection: 8"
United States
-
Front protection: 16"
-
Side protection: 8"
Installation-specific requirements: Floor protection can change depending on hearth height and installation configuration. Additional non-combustible protection with specified thermal resistance may be required.
Blower Operation
The Matrix OB02028 includes a blower rated at up to 90 CFM.
Its purpose is to increase airflow through the heat exchanger and improve warm-air circulation in the room.
The blower includes a heat sensor and can operate automatically once the insert reaches operating temperature. It can also be operated manually.
Blower sizing note: The blower should not be considered a substitute for properly sizing the fireplace insert to the intended heating area.
EPA Emissions & Safety Standards
EPA Status
EPA Phase II / 2020 Cordwood Standard Compliant
Particulate Emissions
1.54 g/h
Particulate Standard
EPA / CSA B415.1-10
U.S. Safety Standards
UL 1482 and UL 737
Canadian Safety Standard
ULC S628
Testing
Safety tested by an accredited laboratory.
Complete Osburn Matrix OB02028 Specifications
| Brand |
Osburn |
| Model |
OB02028 |
| Product Type |
Wood-Burning Fireplace Insert |
| Combustion Technology |
Non-Catalytic |
| Fuel Type |
Dry Cordwood |
| Recommended Heating Area |
500–2,100 sq. ft. |
| Overall Firebox Volume |
2.4 cu. ft. |
| EPA Loading Volume |
2.02 cu. ft. |
| Maximum Burn Time |
8 Hours |
| Maximum Heat Output |
75,000 BTU/h (22.0 kW) |
| Overall Heat Output Rate |
14,800–28,600 BTU/h |
| Average Overall Efficiency |
69% HHV / 74% LHV |
| Optimum Overall Efficiency |
77% |
| Average Particulate Emissions |
1.54 g/h |
| Average CO |
89.4 g/h |
| Maximum Log Length |
20" |
| Log Orientation |
East-West |
| Flue Outlet |
6" |
| Recommended Connector |
6" |
| Chimney Liner Standards |
ULC S635, CAN/ULC-S640, UL 1777 |
| Baffle Material |
C-Cast |
| Mobile Home Installation |
Not Approved |
| Door Type |
Single Glass Door with Cast-Iron Frame |
| Glass Type |
Ceramic Glass |
| Glass Surface |
19 5/8" W × 11 7/8" H |
| Air-Wash System |
Yes |
| Blower |
Included, Up to 90 CFM |
| Overall Dimensions |
36 1/8" W × 25 1/8" H × 23 1/8" D |
| Door Opening |
17 1/2" W × 8 3/4" H |
| Firebox Dimensions |
21" W × 11 7/8" H × 16 3/4" D |
| Minimum Fireplace Opening |
28 7/8" W × 23 3/8" H × 19 5/8" D |
| Body Steel Thickness |
3/16" |
| Top Steel Thickness |
5/16" |
| U.S. Safety Standards |
UL 1482, UL 737 |
| Canadian Safety Standard |
ULC S628 |
| Shipping Weight |
491 lb (223 kg) |
| Warranty |
Limited Lifetime |
Flame Authority Expert Recommendation
Choose the Osburn Matrix OB02028 when you want a substantial non-catalytic wood-burning insert for an appropriate masonry fireplace and need a documented heating range of 500–2,100 sq. ft.
Its 75,000 BTU/h maximum output, 2.4 cu. ft. firebox, 20" log capacity, 8-hour maximum burn time, ceramic-glass door, C-Cast baffle, stainless-steel secondary-air tubes, refractory firebox, and included 90 CFM blower make it a strong zone-heating option for qualifying installations.
The most important buying step is confirming the complete installation—not just the fireplace opening. Verify the 28 7/8" × 23 3/8" × 19 5/8" minimum masonry opening, 6" liner system, minimum venting height, combustible clearances, hearth protection, chimney condition, and applicable local requirements before ordering.
Also Available with Liner Kit
Official Manufacturer Resources
Installation & Owner's Manual
Manufacturer installation, operation, chimney, liner, clearance, hearth-protection, maintenance, and safety information for the OB02028.
Osburn Matrix OB02028 Specification Sheet
Manufacturer specifications covering heating performance, dimensions, firebox information, emissions, construction, and technical data.
Osburn Matrix OB02028 FAQs
How much space can the Osburn Matrix OB02028 heat?
The manufacturer recommends the Matrix OB02028 for heating areas from 500 to 2,100 sq. ft. Actual performance depends on home layout, insulation, climate, chimney draft, fuel quality, and installation conditions.
What is the maximum heat output of the Osburn Matrix OB02028?
The maximum stated heat output with dry cordwood is 75,000 BTU/h (22.0 kW).
What size fireplace opening is required?
The minimum masonry fireplace opening is 28 7/8" W × 23 3/8" H × 19 5/8" D.
What size chimney liner does the Matrix OB02028 use?
The insert has a 6" flue outlet and uses an appropriate stainless-steel chimney liner installed according to the manufacturer instructions.
What is the minimum chimney height?
The total venting-system height should never be less than 15 feet (4.6 m), measured from the appliance-supporting floor to the top of the chimney.
What is the maximum log length?
The maximum log length is 20 inches. Logs are loaded east-west.
Does the Osburn Matrix OB02028 include a blower?
Yes. It includes a blower rated at up to 90 CFM.
How efficient is the Osburn Matrix OB02028?
The supplied data lists 69% average overall efficiency HHV, 74% LHV, and 77% optimum overall efficiency.
Is the Osburn Matrix OB02028 EPA 2020 compliant?
Yes. It is identified as compliant with the 2020 cordwood standard and has an average particulate emissions rate of 1.54 g/h.
Is the Matrix OB02028 approved for mobile-home installation?
No. The OB02028 is not approved for mobile-home or manufactured-home installation.
What are the overall dimensions?
The insert measures 36 1/8" W × 25 1/8" H × 23 1/8" D.
What size firebox does the Matrix have?
The overall firebox volume is 2.4 cu. ft., with approximate dimensions of 21" W × 11 7/8" H × 16 3/4" D.
What floor protection is required in front of the insert?
The standard listed protection is at least 18" in Canada and 16" in the United States in front of the door opening, with 8" side protection. Additional thermal protection may be required depending on the hearth configuration.
What wood moisture level is recommended?
The manufacturer's operating information identifies approximately 15%–20% moisture content as the range that allows the insert to achieve its highest possible efficiency.
How long can the Osburn Matrix burn?
The maximum stated burn time is up to 8 hours. Actual burn time varies with wood species, moisture, load size, chimney draft, climate, and heating demand.
What safety standards apply to the Osburn Matrix OB02028?
The supplied information lists UL 1482 and UL 737 for the United States and ULC S628 for Canada.
What warranty does the Osburn Matrix OB02028 have?
The supplied product information lists a limited lifetime warranty, subject to the manufacturer's complete terms and conditions.
Before You Order
Confirm Before Purchase
- You specifically need the Osburn Matrix OB02028.
- Your masonry fireplace meets the minimum opening dimensions.
- Your chimney can accommodate the required 6" liner system.
- Your total venting-system height can meet the minimum requirement.
- You can maintain the required combustible clearances.
- Your hearth and floor protection satisfy the installation requirements.
- You understand that the insert is not mobile-home approved.
- You plan to burn properly seasoned natural cordwood.
- You understand that heating performance depends on the complete installation and home conditions.
- The insert will be installed according to the manufacturer's instructions and applicable local requirements.
Do Not Assume
- That fireplace opening dimensions alone establish compatibility.
- That the insert can be installed without a suitable chimney liner.
- That a chimney flue serving another appliance can also serve the Matrix.
- That the 75,000 BTU maximum figure is the same as the tested overall heat-output range.
- That HHV, LHV, and optimum efficiency are interchangeable ratings.
- That the blower replaces proper appliance sizing.
- That all hearths require exactly the same floor-protection configuration.
- That the model is approved for mobile-home installation.
Final planning check: Use the Osburn Matrix Installation & Owner's Manual and Specification Sheet to verify fireplace opening, dimensions, chimney liner, venting height, clearances, floor protection, fuel requirements, blower operation, emissions, and safety requirements before installation.
