Kuma Stove And Iron Works K-181 Series: Aspen LE-1 vs Kuma Stove And Iron Works K-251 Series: Ashwood LE-1

Both stoves carry the same certified emission rate: 1.1 g/hr. They tie on efficiency at 78% HHV. The Kuma Stove And Iron Works K-251 Series: Ashwood LE-1 produces more peak heat (30,612 vs 29,153 BTU/h), suiting roughly 850–1,200 sq ft. The Kuma Stove And Iron Works K-251 Series: Ashwood LE-1 has the larger firebox (2.56 vs 1.821 cu ft), which generally means longer burns between reloads.

Kuma Stove And Iron Works K-181 Series: Aspen LE-1 Kuma Stove And Iron Works K-251 Series: Ashwood LE-1
Appliance type wood-stove wood-stove
Combustion technology Catalytic Stove Catalytic Stove
Certified fuel Crib Wood Crib Wood
Emission rate 1.1 g/hr 1.1 g/hr
Efficiency (HHV) 78 % 78 %
Heat output (low) 12764 BTU/h 11219 BTU/h
Heat output (high) 29153 BTU/h 30612 BTU/h
Firebox volume 1.821 cu ft 2.56 cu ft
Carbon monoxide 0.45 g/min 0.49 g/min
25C tax credit eligible (≥75% HHV) Yes Yes
2020 NSPS compliant Yes Yes
Currently in production Yes Yes
EPA certification number 346-23 357-23
Covered model numbers K-181 Series: Aspen LE-1, Tamarack LE-1, Aberdeen LE-1, and Alpine LE-1 K-251 Series: Ashwood LE-1, Wood Classic LE-1, Cambridge LE-1, Cascade LE-1

Frequently asked questions

Which burns cleaner, the Kuma Stove And Iron Works K-181 Series: Aspen LE-1 or the Kuma Stove And Iron Works K-251 Series: Ashwood LE-1?

They are tied: both are certified at 1.1 g/hr of particulates.

Are the Kuma Stove And Iron Works K-181 Series: Aspen LE-1 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.