US1520, HB1520, VG1520, WC1520, N35, C2235, SWF1035, SWF1035K, King KWF1520, Comfort Glow CGWF4000, DuraHeat DHWF4000

Currently certified

EPA lists US1520, HB1520, VG1520, WC1520, N35, C2235, SWF1035, SWF1035K, King KWF1520, Comfort Glow CGWF4000, DuraHeat DHWF4000 under United States Stove Company as a currently certified forced-air furnace.

The listed emission rate is 0.12 pounds per million BTU.

The listed HHV efficiency is 70 percent.

Source: EPA Certified Wood Heater Database, snapshot 2026-10-23.

EPA rows

EPA result rows for this model line
Field Row 1
Status Currently certified
Type Forced Air Furnace
Subtype Non-Catalytic Stove
Emission 0.12 pounds per million BTU
HHV efficiency 70 percent
Heat output 15,997–53,042 BTU/hr
Heat output maximum Not listed
Firebox 3.95 cu ft
CO 4.6 g/min
Certified fuel Cord Wood
Test method Not listed
2020 NSPS Yes
Thermal storage No

Retail names in the model line

These are the names split from EPA's model cell. They are aliases for this line, not separate listings.

Other model lines from this manufacturer

All model lines on the United States Stove Company hub. This page lists 40 of the other 90 lines.

Nearest model lines by EPA figures

Nearest means the smallest absolute difference on that EPA figure, among other Forced Air Furnace model lines that list it. Ties are ordered by model name.

Emission

HHV efficiency

Heat output

United States Stove Company hub · EPA Certified Wood Heater Database