Osburn Horizon Fireplace
Beyond the size. This wood fireplace offers peace of mind due to the combination of energy efficiency and clean heating, and its clean design suits any type of decor.
Large fireplace. Behind its large double glass door sits a 4.73 cubic foot combustion chamber (4.28 cu ft EPA loading volume) that takes logs up to 25" — the longest log of any Osburn appliance.
Low emissions. This energy efficient fireplace complies with the EPA’s clean-air standards at only 1.6 g/h of particulate emissions, in particular through the intelligent air control mechanism, a patented design that optimizes combustion quality.
High efficiency. The Horizon heats 1,000 to 2,800 square feet and burns for up to 11 hours, the longest burn time in the Osburn range.
Features
- Blower included, up to 176 CFM
- Heats 1,000 to 2,800 sq ft with up to 95,000 BTU/h
- 4.73 cu ft firebox that takes logs up to 25"
- Maximum burn time of 11 hours
- EPA 2020 approved, non-catalytic, 1.6 g/h average particulate emissions
- Double ceramic glass doors with cast iron frames and glass air-wash system
- Moulded refractory bricks
- Stainless-steel secondary-air system
- Limited lifetime warranty
What to Order With It
The Horizon Wood Fireplace needs a faceplate and brick panels to be complete. Choose from each required group below.
Osburn and Valcourt are both built by SBI and share many parts, so some links below open our Valcourt listing for the same part number.
Required – faceplate:
Required – brick panels:
Optional:
Performance
| Maximum heat output (dry cordwood) |
95,000 BTU/h |
| Overall heat output range |
16,900 – 43,000 BTU/h (5.0 – 12.6 kW) |
| Recommended heating area |
1,000 – 2,800 sq ft (93 – 260 m²) |
| Average overall efficiency (HHV) |
64% |
| Average overall efficiency (LHV) |
69% |
| Optimum overall efficiency |
70% |
| Average particulate emissions |
1.6 g/h (EPA) |
| Average carbon monoxide |
159 g/h |
| Maximum burn time |
11 hours |
| Overall firebox volume |
4.73 cu ft (0.134 m³) |
| EPA loading volume |
4.28 cu ft (0.121 m³) |
| Recommended log length |
16" (406 mm) |
| Blower |
Included, up to 176 CFM |
Clearances to Combustible Material
The Horizon is a built-in wood fireplace, so these are the figures to hand your builder before framing starts. Osburn states them in words rather than by letter, so they are unambiguous:
| Maximum mantel depth |
6" (152 mm) |
| Minimum mantel height above the door opening |
8" (203 mm) |
| Side wall, measured from the door opening |
24" (610 mm) |
| Minimum distance to the wall in front |
36" (914 mm) |
| Minimum ceiling height, measured from the base of the fireplace |
84" (2.13 m) |
| Enclosure — back, sides and floor beneath the fireplace |
0" (zero clearance) |
| Chimney clearance to combustibles |
2" (50 mm) |
Zero clearance at the back, sides and floor is what makes this a true built-in — but the 84" ceiling height from the fireplace base and the 6" maximum mantel depth are hard limits, and both are easy to miss at the design stage.
Heat Distribution Options
| Forced air distribution kit |
VA4460 (optional) |
| Warm air circulation grille, modern style |
AC01378 (optional) |
| Fresh air intake kit |
Optional |
The forced air kit ducts heat to another room, which is worth considering on a fireplace rated to 2,800 square feet — without it most of the output stays in the room the fireplace is in.
Specifications
| Combustion technology |
Non-catalytic |
| High-efficiency certified appliance |
Yes, EPA 2020 approved |
| Fuel type |
Dry cordwood |
| Maximum log length |
25" (east-west) |
| Log positioning |
Loading over width |
| Chimney diameter |
8" |
| Flue outlet diameter |
8" |
| Type of chimney |
UL 103 HT (2100 °F) |
| Minimum chimney height (feet) |
15' |
| Baffle type |
C-Cast |
| Approved for a mobile home installation |
No |
| Shipping Weight |
560 lb (254 kg) |
| Door type |
Double, glass with cast iron frame |
| Glass type |
Ceramic glass |
| Glass surface – dimensions (Width X Height) |
29 3/4" X 13 1/2" |
| Glass air-wash system |
Yes |
| Premium quality blower included (CFM) |
176 |
| Overall dimension (Height) |
43 3/8" |
| Overall dimension (Width) |
50 3/4" |
| Overall dimension (Depth) |
31 3/4" |
| Door opening – dimension (Height) |
12 3/4" |
| Door opening - dimension (Width) |
33" |
| Firebox – dimension (Height) |
17" |
| Firebox – dimension (Width) |
25 3/8" |
| Firebox – dimension (Depth) |
17 7/8" |
| Moulded refractory bricks |
Yes |
| Stainless-steel secondary-air system improving gas combustion |
Yes |
| USA standard (emissions) |
EPA |
| USA standard (safety) |
UL 127 |
| Tested and listed as per applicable standards |
By an accredited laboratory |
| Warranty |
Limited lifetime |
Framing dimensions appear only on the drawings in the installation manual and dimension sheet below — download both before framing.
Manuals/Documents
