Apprentice answerHow can you tell if an exterior intake louver is installed the wrong way
2nd YearRoof Curbs, Louvers & Exterior AirStop / Verify
Stop before siding/sealing finishes. Louvers have drainage/weather orientation; verify label/blade direction and reinstall per manufacturer/detail if water can be driven into the building.
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Plain-English answer
An exterior louver is not just a grille. It sheds rain, blocks debris, and directs air. If the blades pitch the wrong way, the louver can collect water and dump it into the wall, plenum, or mechanical room.
Verify the manufacturer orientation, drain sill, bird screen side, airflow direction, and wall flashing before cover. The likely fix is to pull and reinstall the louver correctly, then reseal/flashing per the approved exterior wall detail.