My Flagstaff 8528RESS has a front compartment door where my batteries are installed as well as two small side doors (one of each side) where propane tanks are installed. These three compartments are somewhat sealed from the basement area. These three areas all have open floor areas that will drain fluids directly onto the earth ground.
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However these areas will be prone to Battery fumes or Propane fumes and you would not want to install a Power Inverter in either of these three locations. Power Inverters may create sparks with its switching modes electronics and you are warned not to install close to batteries or any other dangerous flammable fumes that may be present...
If your front areas are like mine I would install a Power Inverter like you have referred to in the sealed basement area and use wall vents if one is needed...
Roy Ken