I know what a return vent and a supply vent are, but what I can't find is if any issues will arise if I use a supply vent cover instead of a return air vent cover. My return on my second floor is an odd size (5.75 x 14). I have modernized all the vents and returns in the house except this one. I'd like to use the aria or something similar so it looks more like the wall. The issue is the return vent size available is 10x14. Before I break out the sheet rock, replace the vent, etc. I was wondering if the supply vent was an option. Had hvac in and all is running smoothly as great so the size doesn't need to be increased. I don't see why it would be an issue as it won't stop at from coming in, but I'm not a professional.