Hearthstone Quality Home Heating Products Green Mountain 40 Series: Green Mountain 40 (8640) vs Stove Builder International 1.4R Series: Osburn 950 N

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 1.7 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 Stove Builder International 1.4R Series: Osburn 950 N produces more peak heat (71,279 vs 31,581 BTU/h), suiting roughly 2,050–2,850 sq ft. The Stove Builder International 1.4R Series: Osburn 950 N has the larger firebox (1.67 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 1.4R Series: Osburn 950 N 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 1.4R Series: Osburn 950 N
Appliance type wood-stove wood-stove
Combustion technology Hybrid Non-Catalytic Stove
Certified fuel Crib Wood Cord Wood
Emission rate 1.1 g/hr 1.7 g/hr
Efficiency (HHV) 79 % 74 %
Heat output (low) 13876 BTU/h 18785 BTU/h
Heat output (high) 31581 BTU/h 71279 BTU/h
Firebox volume 1.32 cu ft 1.67 cu ft
Carbon monoxide 0.52 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 210-19 412-26
Covered model numbers Green Mountain 40 Series: Green Mountain 40 (8640), Craftsbury 2 (8392), Hipster 14 (AMB8240) 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 Hearthstone Quality Home Heating Products Green Mountain 40 Series: Green Mountain 40 (8640) or the Stove Builder International 1.4R Series: Osburn 950 N?

The Hearthstone Quality Home Heating Products Green Mountain 40 Series: Green Mountain 40 (8640): 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 Hearthstone Quality Home Heating Products Green Mountain 40 Series: Green Mountain 40 (8640) 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.