Compare
2 vs 5 vs 8 kW diesel heater classes
Compare portable diesel air-heater class ceilings against GarageBTU estimates, with verified VEVOR US product examples and an honest NO_MATCH path.
| Class | Approx BTU ceiling | Typical fit | Trade-off |
|---|---|---|---|
| 2 kW portable diesel | ~6,824 BTU/h | Insulated vans, tiny shops, compact cabins under the calculator’s 2 kW result | Undersized for leaky two-car garages |
| 5 kW portable diesel | ~17,060 BTU/h | Small insulated one-car or tight hobby spaces landing in the 5 kW band | Still limited vs hardwired garage heaters |
| 8 kW portable diesel | ~27,296 BTU/h | Larger hobby garages that clear the 5 kW ceiling but stay under 8 kW | Continuous full fire if the shell is worse than assumed |
| NO_MATCH (above 8 kW) | >27,296 BTU/h | Open pole barns, tall shops, poor insulation with large ΔT | Need insulation, zoning, or a building heater — do not force a portable unit |