HP 21
Previously certified
EPA lists HP 21 under Ningbo Hongsheng Fireplace Company (SMG Hearth and Home, LLC) as a previously certified pellet stove.
The listed emission rate is 1.3 grams per hour.
The listed HHV efficiency is 79 percent.
Source: EPA Certified Wood Heater Database, snapshot 2026-10-23.
EPA rows
| Field | Row 1 |
|---|---|
| Status | Previously certified |
| Type | Pellet Stove |
| Subtype | Non-Catalytic Stove |
| Emission | 1.3 grams per hour |
| HHV efficiency | 79 percent |
| Heat output | 14,820–33,548 BTU/hr |
| Firebox | Not applicable |
| CO | Not listed |
| Certified fuel | Wood Pellets |
| Test method | Not listed |
| 2020 NSPS | 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.
- HP 21
Other model lines from this manufacturer
- HP 61 Previously certified
- HP22 ComfortBilt Previously certified
- HP50S Comfortbilt Previously certified
Nearest model lines by EPA figures
Nearest means the smallest absolute difference on that EPA figure, among other Pellet Stove model lines that list it. Ties are ordered by model name.
Emission
- 5780, AP5780, VG5780, SP5780, and SP58 — 1.3 grams per hour
- 6041, 6041I, SP6000 — 1.3 grams per hour
- Ashby-P II — 1.3 grams per hour
- Austroflamm Wega II — 1.3 grams per hour
- Breckwell and Golden Eagle: SP22E, SP22Ei, 5040E and 5040Ei — 1.3 grams per hour
HHV efficiency
- 25-SSP01,25-SSP01S,55-SHSSP01,55SHSSP01S, 55-TRSSP01, and 55TRSSP01S — 79 percent
- 509-1 Optimum — 79 percent
- Element-P II — 79 percent
- FBX S, FBX S+, FBX T, FBX R, FBX BUMP, ZEFIRO — 79 percent
- G2-ABF66WTS, G2-CBF66WTS, G2-HBF66WTS, G2-JBF66WTS, G2-NBF66WTS — 79 percent
Heat output
- P960, P961, P962 — 10,000–38,500 BTU/hr
- Providence, Providence Signature — 12,800–35,700 BTU/hr
- Harman Allure 50 — 9,001–39,105 BTU/hr
- Deerfield — 10,652–37,391 BTU/hr
- Fox Fire — 10,443–38,263 BTU/hr
Ningbo Hongsheng Fireplace Company (SMG Hearth and Home, LLC) hub · EPA Certified Wood Heater Database