no. unfortunately that doesn't answer my question. i already have aftermarket grilles that i like. the problem is that the cold air return grille is not hinged, making replacing the filter difficult. i'm looking for a way to modify it to make this easier. completely different issue. additionally the ones we found that we like were from a company called Reggio: Here is a link that might be useful: Reggio

First, I figured you would not answer any questions and about 8 years ago I did have a blower test and ESP test done and the manual J performed and none of them would show me the results except to say, I needed a 4.5 ton unit which is on the fence, right? And all said they would have used the same duct work and the blower test was 34 out of like 50 (whatever that value is, I just don't remember). He said not bad and usually sees a lot worse, but could be better and they wanted to gut my duct system and go to all metal duct and both companies pricing was about $6,000 to $7,000 again, about 8 years ago. I had other estimates too, but I don't trust most A/C companies around here as I used to do the repair business years ago and it was mainly window units back then and I know how this business overall operates and you and others online are the exception rather than the rule in residential work. Which is great, but surely you know how bad it is? It is way too competitive and other things I know, I'll just say is very embarrassing to say the least. So, as I do the manual J and D calculations myself I am coming up with between 4 and 4.5 ton system, which you are right, so I see it is going to be oversized. But, I will say we had upper 80 degree days last week and the humiditiy was in the mid 40 percent range in my home as did my 4 ton unit performed and was still comfortable. But, I understand the tighter I make the system, doing as designed will bring the temperature down more quickly and will not be able to control the humidity as well and may become more uncomfortable and cycle more often making it less efficient. Your link is what has made me do what I am doing so far and I thank you for sharing some of your knowledge to the public, I wished I had seen it before I made this move. I know this is not a good excuse, but we had two 14,000 btu portable units in the house this summer and still couldn't keep the temperatue in the house from climbing to 80 degrees during peak outdoor temperature and the central system still would run until midnight before it would shut down briefly. I understand between the leaks and being undersized on return I was losing ground from day one as we bought this model home new. It just seems these portable units would have helped a little bit in keeping the temperature reasonable in our home. I even had a third unit ready to install, but we sweated it out through the end of the cooling season and so, how many would it have taken, 5, 6, or 7 units? Thanks.

If a new grill has the same exterior dimensions, won't the old holes will be covered if the new one's screw holes are in different locations? These things are usually screwed in with small diameter self-tapping screws that are easy to screw in so it really isn't necessary to hit the old holes or to make new guide holes first. Or do you have a different concern in mind?

Rule #1. Use the largest popular size filter grill as possible. Rule #2. There is no such thing as too large when it come's to intake side of system. Rule #3 Use pleated filters (Thicker the better but 1" will surfice) If this is just a grill without filter,I'd choose closer to 500 sq inches than 200 but anything over 400 should be plenty.