Switching to typical filter would be a terrible idea. Look's like an old Lennox and as best I can see the filter is properly installed. You want extra filter sticking out at front and rear,that help's seal. Get away from that fiberglass junk,it let's anything smaller than leaves and feathers pass through and clog your coil. Home Depot Supply,a subsidary of home depot carry's exelent spun polyester media in a cut to fit roll that yeilds several filters. Ask customer service counter to order it for you. If they don't know what you are talking about call local apartment comunities to find one that buy's from HDS. They likly don't order this filter but can have it dropped off at their office in a day or two. An emergency filter can be made by removeing center of a typical pleated filter. Keep in mind a 30"x 20" pleated unfolds to about 30"x 40",you might get two filters out of the largest filter on retail shelf.

Thank you very much for your help! I will take your advice and use a polyester media instead.

You are welcome and I uverlooked suggesting you check with lennox dealers and hvac wholesale parts houses for media. Don't let them talk you into fiberglass.

can hammock filter be fitted to trap oil in range hood?

Does anyone know who took this picture and if I can use it in a module I am writing on furnace filters? Did the person who started this conversation take the picture? Looking for permission to use if possible. thanks