The ROVSUN RS-HCG18K 18,000 BTU is the better propane heater overall, rated 4.5 to 3.9. The ROVSUN RS-HCG18K 18,000 BTU leads on safety and value. The Mr. Heater Big Buddy MH18B wins on fuel options. The ROVSUN RS-HCG18K 18,000 BTU costs $122.27 less ($117.99 vs $240.26).
A low cost 18,000 BTU cabinet heater for well ventilated garages, sheds and patios, with tip, low oxygen and flame out shutoffs. The maker requires good ventilation indoors.
Amazon $117.99For heating a ventilated cabin, ice shack or large tent that a 9,000 BTU Buddy can’t keep warm. Give it the 18 sq in of fresh air at floor and ceiling the maker requires.
Mr. Heater $240.26Prices were last checked October 30, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.
Each factor is scored 0-100 against the same fixed reference points for every portable propane heater; a clear win is highlighted. How we rank explains each one.
| Factor weight | ROVSUN RS-HCG18K 18,000 BTU | Mr. Heater Big Buddy MH18B |
|---|---|---|
| Overall rating | 4.5/5 | 3.9/5 |
| Value 25% | 80 $6.55 per 1,000 BTU ($117.99, 18,000 BTU) | 29 $13.35 per 1,000 BTU ($240.26, 18,000 BTU) |
| Safety 30% | 100 SGS listed, low-oxygen shutoff, tip-over shutoff, flame-out shutoff | 50 low-oxygen shutoff, tip-over shutoff; no safety listing published |
| Warranty 15% | 50 warranty not published (neutral score used) | 100 3-year warranty |
| Turndown 15% | 95 turns down to 6,000 BTU | 100 turns down to 4,000 BTU |
| Ignition 10% | 100 push-button piezo ignition | 100 push-button piezo ignition |
| Fuel options 5% | 50 runs on a bulk tank only | 100 runs on 1 lb cylinders or a bulk tank |
| ROVSUN RS-HCG18K 18,000 BTU | Mr. Heater Big Buddy MH18B | |
|---|---|---|
| Heating | ||
| Heat output | 6,000 to 18,000 BTU | 4,000 to 18,000 BTU |
| Type | Portable | Portable |
| Use | Indoor (ventilated) | Indoor (ventilated) |
| Heats up to | 450 sq ft | 450 sq ft |
| Thermostat | No | No |
| Fan | No | No |
| Fuel and power | ||
| Fuel | Bulk tank | 1 lb cylinder or bulk tank |
| Hose included | Yes | No |
| Ignition | Push-button piezo | Push-button piezo |
| Power needed | None | None |
| Safety | ||
| Safety listing | SGS | None published |
| Low-oxygen shutoff | Yes | Yes |
| Tip-over shutoff | Yes | Yes |
| Flame-out shutoff | Yes | - |
| Build | ||
| Noise | 32 dB | - |
| Dimensions | 17.7 x 15 x 21.9 in | - |
| Weight | 16.5 lb | 17.1 lb |
| Warranty | - | 3 years |
