I've always used cheap 1" fibereglass filters for our unit, the return holds 2-20x20, side by side.
I want to use something a little better than these. Since we have a rooftop unit, adding any other type of filter setup would be a pain.
What would be a decent low restriction 1" filter that we could use? The big box stores have many different choices and they all look restrictive but I'm sure some are a lot worse than others. Thanks.