Hearth and Home Technologies Quadra-Fire 21M-ACC-C vs Hearth and Home Technologies Vermont Castings Defiant 1975-CAT-C
The Hearth and Home Technologies Vermont Castings Defiant 1975-CAT-C is the cleaner burner: 1.3 g/hr certified particulate emissions versus 1.7 g/hr. The Hearth and Home Technologies Vermont Castings Defiant 1975-CAT-C is the more efficient unit: 78% versus 76% HHV — more heat from every cord. The Hearth and Home Technologies Quadra-Fire 21M-ACC-C produces more peak heat (29,322 vs 25,471 BTU/h), suiting roughly 850–1,150 sq ft. The Hearth and Home Technologies Vermont Castings Defiant 1975-CAT-C has the larger firebox (3.25 vs 1.48 cu ft), which generally means longer burns between reloads. Combustion technology differs: the Hearth and Home Technologies Quadra-Fire 21M-ACC-C is a non-catalytic stove and the Hearth and Home Technologies Vermont Castings Defiant 1975-CAT-C a catalytic stove — see the catalytic vs non-catalytic guide for what that means day to day.
| Hearth and Home Technologies Quadra-Fire 21M-ACC-C | Hearth and Home Technologies Vermont Castings Defiant 1975-CAT-C | |
|---|---|---|
| Appliance type | wood-stove | wood-stove |
| Combustion technology | Non-Catalytic Stove | Catalytic Stove |
| Certified fuel | Crib Wood | Crib Wood |
| Emission rate | 1.7 g/hr | 1.3 g/hr |
| Efficiency (HHV) | 76 % | 78 % |
| Heat output (low) | 13585 BTU/h | 11974 BTU/h |
| Heat output (high) | 29322 BTU/h | 25471 BTU/h |
| Firebox volume | 1.48 cu ft | 3.25 cu ft |
| Carbon monoxide | 1.5 g/min | 1.46 g/min |
| 25C tax credit eligible (≥75% HHV) | Yes | Yes |
| 2020 NSPS compliant | Yes | Yes |
| Currently in production | Yes | Yes |
| EPA certification number | 250-20 | 212-19 |
| Covered model numbers | Quadra-Fire 21M-ACC-C, Discovery-1-C, FF-WP-100 | Vermont Castings Defiant 1975-CAT-C |
Frequently asked questions
Which burns cleaner, the Hearth and Home Technologies Quadra-Fire 21M-ACC-C or the Hearth and Home Technologies Vermont Castings Defiant 1975-CAT-C?
The Hearth and Home Technologies Vermont Castings Defiant 1975-CAT-C: 1.3 g/hr certified particulate emissions versus 1.7 g/hr for the Hearth and Home Technologies Quadra-Fire 21M-ACC-C.
Are the Hearth and Home Technologies Quadra-Fire 21M-ACC-C and Hearth and Home Technologies Vermont Castings Defiant 1975-CAT-C 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.