DeWalt DXH90FAV 90,000 BTU
#4 in Forced airFull review
For job sites, barns and large garages with fresh air that need more heat than a 65,000 BTU heater. It is a construction heater, not for living spaces.
Amazon $230.77$230.77
The DeWalt DXH90FAV 90,000 BTU is the better propane heater overall, rated 3.5 to 3.1. The DeWalt DXH90FAV 90,000 BTU leads on safety and turndown. The Mr. Heater MH400FAVT 400,000 BTU wins on value. The DeWalt DXH90FAV 90,000 BTU costs $435.07 less ($230.77 vs $665.84).
Mr. Heater MH400FAVT 400,000 BTU
#12 in Forced airFull review
For large construction sites, barns and warehouses that need heat on an industrial scale from a bank of 100 lb tanks. Use it only with plenty of fresh air.
Amazon $665.84$665.84
Prices 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.
Which should you buy?
- Choose the DeWalt DXH90FAV 90,000 BTU for safety (ETL listed, flame-out shutoff vs none stated; no safety listing published) and turndown (turns down to 50,000 BTU vs turns down to 250,000 BTU).
- Choose the Mr. Heater MH400FAVT 400,000 BTU for value ($1.66 per 1,000 BTU ($665.84, 400,000 BTU) vs $2.56 per 1,000 BTU ($230.77, 90,000 BTU)).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every forced air propane heater; a clear win is highlighted. How we rank explains each one.
| Factor weight | DeWalt DXH90FAV 90,000 BTU | Mr. Heater MH400FAVT 400,000 BTU |
|---|---|---|
| Overall rating | 3.5/5 | 3.1/5 |
| Value 25% | 41 $2.56 per 1,000 BTU ($230.77, 90,000 BTU) | 68 $1.66 per 1,000 BTU ($665.84, 400,000 BTU) |
| Safety 30% | 80 ETL listed, flame-out shutoff | 30 none stated; no safety listing published |
| Warranty 15% | 0 1-year warranty | 0 1-year warranty |
| Turndown 15% | 63 turns down to 50,000 BTU | 54 turns down to 250,000 BTU |
| Ignition 10% | 100 electric ignition | 100 electric ignition |
| Fuel options 5% | 50 runs on a bulk tank only | 50 runs on a bulk tank only |
Specifications
| DeWalt DXH90FAV 90,000 BTU | Mr. Heater MH400FAVT 400,000 BTU | |
|---|---|---|
| Heating | ||
| Heat output | 50,000 to 90,000 BTU | 250,000 to 400,000 BTU |
| Type | Forced air | Forced air |
| Use | Job sites and garages | Job sites and garages |
| Heats up to | 2,250 sq ft | 10,000 sq ft |
| Thermostat | No | Yes |
| Fan | Yes | Yes |
| Fuel and power | ||
| Fuel | Bulk tank | Bulk tank |
| Hose included | Yes | Yes |
| Ignition | Electric | Electric |
| Power needed | 120 V outlet | 120 V outlet |
| Safety | ||
| Safety listing | ETL | None published |
| Flame-out shutoff | Yes | - |
| Build | ||
| Dimensions | - | 21.9 x 38.6 x 14.8 in |
| Weight | - | 56.4 lb |
| Warranty | 1 year | 1 year |
| Released | 2012-10 | 2010-01 |