Hearthstone Quality Home Heating Products Clydesdale 8492 vs Hearthstone Quality Home Heating Products Green Mountain 40 Series: Green Mountain 40 (8640)

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 1.16 g/hr. They tie on efficiency at 79% HHV. The Hearthstone Quality Home Heating Products Clydesdale 8492 produces more peak heat (32,588 vs 31,581 BTU/h), suiting roughly 950–1,300 sq ft. The Hearthstone Quality Home Heating Products Clydesdale 8492 has the larger firebox (2.35 vs 1.32 cu ft), which generally means longer burns between reloads.

Hearthstone Quality Home Heating Products Clydesdale 8492 Hearthstone Quality Home Heating Products Green Mountain 40 Series: Green Mountain 40 (8640)
Appliance type wood-stove wood-stove
Combustion technology Hybrid Hybrid
Certified fuel Crib Wood Crib Wood
Emission rate 1.16 g/hr 1.1 g/hr
Efficiency (HHV) 79 % 79 %
Heat output (low) 14829 BTU/h 13876 BTU/h
Heat output (high) 32588 BTU/h 31581 BTU/h
Firebox volume 2.35 cu ft 1.32 cu ft
Carbon monoxide 1.1 g/min 0.52 g/min
25C tax credit eligible (≥75% HHV) Yes Yes
2020 NSPS compliant Yes Yes
Currently in production Yes Yes
EPA certification number 305-22 210-19
Covered model numbers Clydesdale 8492 Green Mountain 40 Series: Green Mountain 40 (8640), Craftsbury 2 (8392), Hipster 14 (AMB8240)

Frequently asked questions

Which burns cleaner, the Hearthstone Quality Home Heating Products Clydesdale 8492 or the Hearthstone Quality Home Heating Products Green Mountain 40 Series: Green Mountain 40 (8640)?

The Hearthstone Quality Home Heating Products Green Mountain 40 Series: Green Mountain 40 (8640): 1.1 g/hr certified particulate emissions versus 1.16 g/hr for the Hearthstone Quality Home Heating Products Clydesdale 8492.

Are the Hearthstone Quality Home Heating Products Clydesdale 8492 and Hearthstone Quality Home Heating Products Green Mountain 40 Series: Green Mountain 40 (8640) 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.