Hearthstone Quality Home Heating Products Green Mountain 40 Series: Green Mountain 40 (8640) vs New Buck Corporation (Buck Stove Corp.) Model 91
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 1.3 g/hr. The New Buck Corporation (Buck Stove Corp.) Model 91 is the more efficient unit: 80% versus 79% HHV — more heat from every cord. The New Buck Corporation (Buck Stove Corp.) Model 91 produces more peak heat (43,190 vs 31,581 BTU/h), suiting roughly 1,250–1,750 sq ft. The New Buck Corporation (Buck Stove Corp.) Model 91 has the larger firebox (3.07 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 New Buck Corporation (Buck Stove Corp.) Model 91 a 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) | New Buck Corporation (Buck Stove Corp.) Model 91 | |
|---|---|---|
| Appliance type | wood-stove | wood-stove |
| Combustion technology | Hybrid | Catalytic Stove |
| Certified fuel | Crib Wood | Crib Wood |
| Emission rate | 1.1 g/hr | 1.3 g/hr |
| Efficiency (HHV) | 79 % | 80 % |
| Heat output (low) | 13876 BTU/h | 14206 BTU/h |
| Heat output (high) | 31581 BTU/h | 43190 BTU/h |
| Firebox volume | 1.32 cu ft | 3.07 cu ft |
| Carbon monoxide | 0.52 g/min | 0.6 g/min |
| 25C tax credit eligible (≥75% HHV) | Yes | Yes |
| 2020 NSPS compliant | Yes | Yes |
| Currently in production | Yes | Yes |
| EPA certification number | 210-19 | 239-19 |
| Covered model numbers | Green Mountain 40 Series: Green Mountain 40 (8640), Craftsbury 2 (8392), Hipster 14 (AMB8240) | Model 91, Carolina 92 |
Frequently asked questions
Which burns cleaner, the Hearthstone Quality Home Heating Products Green Mountain 40 Series: Green Mountain 40 (8640) or the New Buck Corporation (Buck Stove Corp.) Model 91?
The Hearthstone Quality Home Heating Products Green Mountain 40 Series: Green Mountain 40 (8640): 1.1 g/hr certified particulate emissions versus 1.3 g/hr for the New Buck Corporation (Buck Stove Corp.) Model 91.
Are the Hearthstone Quality Home Heating Products Green Mountain 40 Series: Green Mountain 40 (8640) and New Buck Corporation (Buck Stove Corp.) Model 91 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.