Stove Builder International 3.5 Series (Solution 3.5
Stove Builder International 3.5 Series (Solution 3.5 is a non-catalytic wood stove from Stove Builder International certified at 1.6 g/hr particulate emissions with 71% HHV efficiency and a 17,200–57,800 BTU/h output range.
| Appliance type | wood-stove |
|---|---|
| Combustion technology | Non-Catalytic Stove |
| Certified fuel | Cord Wood |
| Covered model numbers | 3.5 Series (Solution 3.5, Osburn 3500, Gateway 3500, Escape 2100, HT-3000, Solution 3.5-I, FW3500, Osburn 3500-I, HES350, Hei350, Blue Ridge 500, Escape 2100-I, CW3500, Blue Ridge 500-I) |
| Emission rate | 1.6 g/hr |
|---|---|
| Carbon monoxide | 1.2 g/min |
| Efficiency (HHV) | 71 % |
|---|
| Heat output (low) | 17200 BTU/h |
|---|---|
| Heat output (high) | 57800 BTU/h |
| Firebox volume | 2.88 cu ft |
| 25C tax credit eligible (≥75% HHV) | No |
|---|---|
| 2020 NSPS compliant | Yes |
| Currently in production | Yes |
| EPA certification number | 142-18 |
What space does the Stove Builder International 3.5 Series (Solution 3.5 suit?
- Its 57,800 BTU/h peak output covers roughly 1,650–2,300 sq ft at the 25–35 BTU/h-per-square-foot rule of thumb — see the sizing calculator to adjust for your insulation and climate.
- The 2.88 cu ft firebox puts it in the mid-size home class.
- Rough fuel use: about 2.9 cords per season at the midpoint of its output range (8 burn-hours/day, 150-day season, 22 MMBtu/cord — see methodology).
- Certified burning Cord Wood — the test fuel closest to real-world firewood.
Similar wood stoves
- Travis Industries Large Flush Wood Hybrid Fyre Insert (1.9 g/hr)
- Stove Builder International 3.3 Series Osburn 3300 (0.95 g/hr)
- Jotul North America (Jotul U.S.A., Inc.) F45V2 (1.8 g/hr)
- Woodstock Soapstone Company Fireview Soapstone Stove 205b (1.6 g/hr)
- Jotul North America (Jotul U.S.A., Inc.) F35 (1.2 g/hr)
- New Buck Corporation (Buck Stove Corp.) Model 81 (1.1 g/hr)
Frequently asked questions
Is the Stove Builder International 3.5 Series (Solution 3.5 EPA certified?
Yes, the Stove Builder International 3.5 Series (Solution 3.5 is on the EPA's current list of certified wood heaters (certification number 142-18) and meets the 2020 NSPS Step 2 emission limits.
What is the Stove Builder International 3.5 Series (Solution 3.5's emission rate?
The Stove Builder International 3.5 Series (Solution 3.5 is certified at 1.6 grams of particulates per hour (tested with cord wood). Real-world emissions depend heavily on fuel moisture and operation — the lab figure assumes seasoned fuel and correct air settings.
How many square feet can the Stove Builder International 3.5 Series (Solution 3.5 heat?
Roughly 1,650–2,300 sq ft, estimated from its 57,800 BTU/h peak output at 25–35 BTU/h per square foot. Insulation, climate, ceiling height, and floor plan move this figure substantially in both directions.
Does the Stove Builder International 3.5 Series (Solution 3.5 qualify for a federal tax credit?
No — the federal 25C credit for biomass stoves was terminated for property placed in service after December 31, 2025. The Stove Builder International 3.5 Series (Solution 3.5's certified efficiency is 71% HHV, which did not meet the credit's ≥75% HHV threshold while it existed. State and local incentive programs may still apply — check your state energy office and air district.
Sources
- cfpub.epa.gov (retrieved 2026-07-23)