My maintenance person has been using really cheap filters of one brand, encasing them in a metal frame of another frame, duct taping them so they'll stay together, and just undoing the door with slide locks. They are using a 13" filter, but the unit is 14", and I can't seem to find a 13" filter anywhere. We were also informed by an outside source we need at least a Merv8, but all I've seen are 700 and 1500, so I guess I'll have to find them online somewhere. It took a while (15 mins). The maintenance man just undoes the slide bar, but I took off the end bar (2 screws) and opened the whole end, and fiddled it in. Is this the correct way to do this ? Thanks for any info you can help me with this problem.:confused: