If, during mop-up / overhaul, you want to get rid of any remnant exhaust smells inside a structure, just turn the gas-powered VENTRY Fan around, place it directly in the doorway and blow out. Have as many windows and doors open in the house as possible. This is a good use of negative pressure. The fan will suck the air out of the structure, blow it outside, and pull 100% fresh air into and through the structure. This is only to be done after all the smoke is removed, so as not to damage the fan.

Placing the fan in the doorway facing outside, with as many windows open as possible in the house, will pull out any remaining carbon monoxide from a structure and pull 100% fresh air through the house. (Wait until the smoke is gone so that it will not be pulled through the engine and cause damage.)

Of course, you can also use Electric Fans which completely eliminate any carbon monoxide issues arising from the fan use.