Osburn
Model: Osburn 3500
The Osburn 3500 insert is one of the largest wood inserts you can buy — up to 2,700 square feet of heat and 22-inch logs, with burns up to ten hours. For big masonry fireplaces that deserve big heat.
Features
- Glass air-wash system
- Firebox lined with refractory bricks for better heat distribution
- Stainless-steel secondary-air system improving gas combustion
Specifications
| Fuel type | Dry cordwood (16" recommended) |
|---|---|
| Recommended heating area (ft²) | 1,000 - 2,700 |
| Overall firebox volume (ft³) | 3.5 |
| EPA loading volume (ft³) | 2.88 |
| Maximum burn time | 10 h |
| Maximum heat output (dry cordwood) | 110,000 BTU/h (32.2 kW) |
| Overall heat output rate | 17,200 BTU/h (5.0 kW) to 57,800 BTU/h (16.9 kW) |
| Average overall efficiency (dry cordwood) | 71 % (HHV) / 76 % (LHV) |
| Optimum overall efficiency | 77 % |
| Optimum heat transfer efficiency | 75 % |
| Average particulate emissions rate | 1.6 g/h |
| Average CO | 73 g/h |
| Combustion technology | Non-catalytic |
| High-efficiency certified appliance | Yes, EPA 2020 approved |
| Maximum log length | 22" |
| Log positioning | Loading over width and over depth |
| Chimney diameter | 6" |
| Flue outlet diameter | 6" |
| Type of chimney | Liner - ULC-S635, CAN/ULC-S640, UL1777 |
| Minimum chimney height (feet) | 15' |
| Baffle type | C-Cast or equivalent |
| Shipping Weight | 540 lb (245 kg) |
| Door type | Single, glass with cast iron frame |
| Glass type | Ceramic glass |
| Glass surface – dimensions (Width X Height) | 19" X 11 3/4" |
| Premium quality blower included (CFM) | 144 |
| Overall dimension (Height) | 24 7/8" |
| Overall dimension (Width) | 30 3/8" |
| Overall dimension (Depth) | 29" |
| Door opening – dimension (Height) | 9 7/8" |
| Door opening - dimension (Width) | 19" |
| Firebox – dimension (Height) | 12 7/8" |
| Firebox – dimension (Width) | 22 7/8" |
| Firebox – dimension (Depth) | 20 1/8" |
| Steel thickness – body | 3/16" |
| Steel thickness – top | 5/16" |
| Fireplace opening – minimum (Height) | 26 1/4" |
| Fireplace opening – minimum (Width) | 31" |
| Fireplace opening – minimum (Depth) | 18 3/8" |
| USA standard (emissions) | EPA |
| Canadian Standard (emissions) | CSA B415.1-10 |
| USA standard (safety) | UL 1482, UL 737 |
| Canadian standard (safety) | ULC S628 |
| Tested and listed as per applicable standards | By an accredited laboratory (CAN/USA) |
| Warranty | Limited lifetime |
| Model number | OB03510 |
Options & Accessories
Downloads & Resources
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