Jotul North America (Jotul U.S.A., Inc.) F35 vs Kuma Stove And Iron Works K-251 Series: Ashwood LE-1

The Kuma Stove And Iron Works K-251 Series: Ashwood LE-1 is the cleaner burner: 1.1 g/hr certified particulate emissions versus 1.2 g/hr. The Kuma Stove And Iron Works K-251 Series: Ashwood LE-1 is the more efficient unit: 78% versus 69% HHV — more heat from every cord. The Jotul North America (Jotul U.S.A., Inc.) F35 produces more peak heat (59,443 vs 30,612 BTU/h), suiting roughly 1,700–2,400 sq ft. The Kuma Stove And Iron Works K-251 Series: Ashwood LE-1 has the larger firebox (2.56 vs 1.57 cu ft), which generally means longer burns between reloads. Combustion technology differs: the Jotul North America (Jotul U.S.A., Inc.) F35 is a non-catalytic stove and the Kuma Stove And Iron Works K-251 Series: Ashwood LE-1 a catalytic stove — see the catalytic vs non-catalytic guide for what that means day to day.

Jotul North America (Jotul U.S.A., Inc.) F35 Kuma Stove And Iron Works K-251 Series: Ashwood LE-1
Appliance type wood-stove wood-stove
Combustion technology Non-Catalytic Stove Catalytic Stove
Certified fuel Cord Wood Crib Wood
Emission rate 1.2 g/hr 1.1 g/hr
Efficiency (HHV) 69 % 78 %
Heat output (low) 13533 BTU/h 11219 BTU/h
Heat output (high) 59443 BTU/h 30612 BTU/h
Firebox volume 1.57 cu ft 2.56 cu ft
Carbon monoxide 1.35 g/min 0.49 g/min
25C tax credit eligible (≥75% HHV) No Yes
2020 NSPS compliant Yes Yes
Currently in production Yes Yes
EPA certification number 317-22 357-23
Covered model numbers F35 K-251 Series: Ashwood LE-1, Wood Classic LE-1, Cambridge LE-1, Cascade LE-1

Frequently asked questions

Which burns cleaner, the Jotul North America (Jotul U.S.A., Inc.) F35 or the Kuma Stove And Iron Works K-251 Series: Ashwood LE-1?

The Kuma Stove And Iron Works K-251 Series: Ashwood LE-1: 1.1 g/hr certified particulate emissions versus 1.2 g/hr for the Jotul North America (Jotul U.S.A., Inc.) F35.

Are the Jotul North America (Jotul U.S.A., Inc.) F35 and Kuma Stove And Iron Works K-251 Series: Ashwood LE-1 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.