Kuma Stove And Iron Works K-251 Series: Ashwood LE-1 vs Stove Builder International 1.4R Series: Osburn 950 N
The Kuma Stove And Iron Works K-251 Series: Ashwood LE-1 is the cleaner burner: 1.1 g/hr certified particulate emissions versus 1.7 g/hr. The Kuma Stove And Iron Works K-251 Series: Ashwood LE-1 is the more efficient unit: 78% versus 74% HHV — more heat from every cord. The Stove Builder International 1.4R Series: Osburn 950 N produces more peak heat (71,279 vs 30,612 BTU/h), suiting roughly 2,050–2,850 sq ft. The Kuma Stove And Iron Works K-251 Series: Ashwood LE-1 has the larger firebox (2.56 vs 1.67 cu ft), which generally means longer burns between reloads. Combustion technology differs: the Kuma Stove And Iron Works K-251 Series: Ashwood LE-1 is a catalytic stove and the Stove Builder International 1.4R Series: Osburn 950 N a non-catalytic stove — see the catalytic vs non-catalytic guide for what that means day to day.
| Kuma Stove And Iron Works K-251 Series: Ashwood LE-1 | Stove Builder International 1.4R Series: Osburn 950 N | |
|---|---|---|
| Appliance type | wood-stove | wood-stove |
| Combustion technology | Catalytic Stove | Non-Catalytic Stove |
| Certified fuel | Crib Wood | Cord Wood |
| Emission rate | 1.1 g/hr | 1.7 g/hr |
| Efficiency (HHV) | 78 % | 74 % |
| Heat output (low) | 11219 BTU/h | 18785 BTU/h |
| Heat output (high) | 30612 BTU/h | 71279 BTU/h |
| Firebox volume | 2.56 cu ft | 1.67 cu ft |
| Carbon monoxide | 0.49 g/min | 1.3 g/min |
| 25C tax credit eligible (≥75% HHV) | Yes | No |
| 2020 NSPS compliant | Yes | Yes |
| Currently in production | Yes | Yes |
| EPA certification number | 357-23 | 412-26 |
| Covered model numbers | K-251 Series: Ashwood LE-1, Wood Classic LE-1, Cambridge LE-1, Cascade LE-1 | 1.4R Series: Osburn 950 N, Escape 1200 N, Gateway 1400 N, Solution 1.4 N, Spark II N, Fox N, Deco Nano N, S250 N, HES140 N, Blue Ridge 100 N, SP1400 N, SL1400 N |
Frequently asked questions
Which burns cleaner, the Kuma Stove And Iron Works K-251 Series: Ashwood LE-1 or the Stove Builder International 1.4R Series: Osburn 950 N?
The Kuma Stove And Iron Works K-251 Series: Ashwood LE-1: 1.1 g/hr certified particulate emissions versus 1.7 g/hr for the Stove Builder International 1.4R Series: Osburn 950 N.
Are the Kuma Stove And Iron Works K-251 Series: Ashwood LE-1 and Stove Builder International 1.4R Series: Osburn 950 N both EPA certified?
Yes — both appear on the U.S. EPA's current list of certified wood heaters, and every figure on this page comes from their certification records.