Hearth and Home Technologies Quadra-Fire 21M-ACC-C vs Stove Builder International 1.4 Series (Osburn 950
The Hearth and Home Technologies Quadra-Fire 21M-ACC-C is the cleaner burner: 1.7 g/hr certified particulate emissions versus 1.8 g/hr. The Hearth and Home Technologies Quadra-Fire 21M-ACC-C is the more efficient unit: 76% versus 74% HHV — more heat from every cord. The Hearth and Home Technologies Quadra-Fire 21M-ACC-C produces more peak heat (29,322 vs 26,500 BTU/h), suiting roughly 850–1,150 sq ft. The Stove Builder International 1.4 Series (Osburn 950 has the larger firebox (1.55 vs 1.48 cu ft), which generally means longer burns between reloads.
| Hearth and Home Technologies Quadra-Fire 21M-ACC-C | Stove Builder International 1.4 Series (Osburn 950 | |
|---|---|---|
| Appliance type | wood-stove | wood-stove |
| Combustion technology | Non-Catalytic Stove | Non-Catalytic Stove |
| Certified fuel | Crib Wood | Cord Wood |
| Emission rate | 1.7 g/hr | 1.8 g/hr |
| Efficiency (HHV) | 76 % | 74 % |
| Heat output (low) | 13585 BTU/h | 12100 BTU/h |
| Heat output (high) | 29322 BTU/h | 26500 BTU/h |
| Firebox volume | 1.48 cu ft | 1.55 cu ft |
| Carbon monoxide | 1.5 g/min | 1.2 g/min |
| 25C tax credit eligible (≥75% HHV) | Yes | No |
| 2020 NSPS compliant | Yes | Yes |
| Currently in production | Yes | Yes |
| EPA certification number | 250-20 | 289-21 |
| Covered model numbers | Quadra-Fire 21M-ACC-C, Discovery-1-C, FF-WP-100 | 1.4 Series (Osburn 950, Escape 1200, Gateway 1400, Solution 1.4, Spark II, Fox, Déco Nano, S250, Harmony 1.4, HES140, Blue Ridge 100) |
Frequently asked questions
Which burns cleaner, the Hearth and Home Technologies Quadra-Fire 21M-ACC-C or the Stove Builder International 1.4 Series (Osburn 950?
The Hearth and Home Technologies Quadra-Fire 21M-ACC-C: 1.7 g/hr certified particulate emissions versus 1.8 g/hr for the Stove Builder International 1.4 Series (Osburn 950.
Are the Hearth and Home Technologies Quadra-Fire 21M-ACC-C and Stove Builder International 1.4 Series (Osburn 950 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.