Hearthstone Quality Home Heating Products Green Mountain 40 Series: Green Mountain 40 (8640) vs Stove Builder International 1.4 Series (Osburn 950
The Hearthstone Quality Home Heating Products Green Mountain 40 Series: Green Mountain 40 (8640) is the cleaner burner: 1.1 g/hr certified particulate emissions versus 1.8 g/hr. The Hearthstone Quality Home Heating Products Green Mountain 40 Series: Green Mountain 40 (8640) is the more efficient unit: 79% versus 74% HHV — more heat from every cord. The Hearthstone Quality Home Heating Products Green Mountain 40 Series: Green Mountain 40 (8640) produces more peak heat (31,581 vs 26,500 BTU/h), suiting roughly 900–1,250 sq ft. The Stove Builder International 1.4 Series (Osburn 950 has the larger firebox (1.55 vs 1.32 cu ft), which generally means longer burns between reloads. Combustion technology differs: the Hearthstone Quality Home Heating Products Green Mountain 40 Series: Green Mountain 40 (8640) is a hybrid and the Stove Builder International 1.4 Series (Osburn 950 a non-catalytic stove — see the catalytic vs non-catalytic guide for what that means day to day.
| Hearthstone Quality Home Heating Products Green Mountain 40 Series: Green Mountain 40 (8640) | Stove Builder International 1.4 Series (Osburn 950 | |
|---|---|---|
| Appliance type | wood-stove | wood-stove |
| Combustion technology | Hybrid | Non-Catalytic Stove |
| Certified fuel | Crib Wood | Cord Wood |
| Emission rate | 1.1 g/hr | 1.8 g/hr |
| Efficiency (HHV) | 79 % | 74 % |
| Heat output (low) | 13876 BTU/h | 12100 BTU/h |
| Heat output (high) | 31581 BTU/h | 26500 BTU/h |
| Firebox volume | 1.32 cu ft | 1.55 cu ft |
| Carbon monoxide | 0.52 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 | 210-19 | 289-21 |
| Covered model numbers | Green Mountain 40 Series: Green Mountain 40 (8640), Craftsbury 2 (8392), Hipster 14 (AMB8240) | 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 Hearthstone Quality Home Heating Products Green Mountain 40 Series: Green Mountain 40 (8640) or the Stove Builder International 1.4 Series (Osburn 950?
The Hearthstone Quality Home Heating Products Green Mountain 40 Series: Green Mountain 40 (8640): 1.1 g/hr certified particulate emissions versus 1.8 g/hr for the Stove Builder International 1.4 Series (Osburn 950.
Are the Hearthstone Quality Home Heating Products Green Mountain 40 Series: Green Mountain 40 (8640) 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.