My new Carrier AC (model FK4) came with a custom sized AC filter which appears to be made from low quality blue fiber glass. It is about 21 1/8 x 24x1 Does anyone think there will be any problems with installing a standard 20x24x1 filter? I purchased a cheap fiber glass filter as a test from a local home center and it appears to have fit. I would like to purchase a better quality filter but before I spend the money I what to be sure there will be no long range problems.
Any thoughts would be greatly appreciated.