Can I put my generator in the garage if I vent it?
It is not recommended by generator manufacturers to ever run a generator in a garage.  There are many safety considerations, the foremost being carbon monoxide exposure.  Even with ventilation, a small leak could cause toxic exposure as the gas could enter the home or business.  Remember, carbon monoxide is odorless and colorless.  In addition, carbon monoxide can be flammable.  A spark could cause a fire.