The previous air filter location in our furnace room was a joke. It was located behind the service door to the furnace and right below the blower. Every time the blower would kick on, the filter would get sucked up into it leaving huge gaps for unfiltered air to pass through. Upon the recommendation of a plumber/HVAC tech we had out to the house, we decided to replace the air grille that feeds into the furnace with an alternate type that has an air filter attached to it.
Finding an air grille that would fit our existing hole proved to be a challenge and I ended up ordering one online and had it shipped in. The first grille that arrived was damaged in transport. Lucky for me, the company in which I purchased the grille sent me a replacement free of charge. A few days later and I had my new grille.
Overall the project took about an hour to complete. I had to take off the old grille and then notch out the 2×4’s located behind it to accommodate the depth of the new grille. Then it was just a matter of cleaning out the junk the builders left in the air box and wiping down the entire box with cleaner. Not a bad project but not sure if it’s one I would want to tackle again.