the problem I was having was the filter has dark gray foam on the ends and the printing is black, so the words "air flow" were not hardly visible.(Id take a pic but dont need to go that far). Since there is nothing stamped in the compartment itself to advise I was left to guess. So I took a photo and enlarged it very big and faintly saw the words air flow with a downward arrow. Add to that the blower motor fan sits below the filter so I've been told it needs to point to that as well. Mystery solved