What are the most obtainable common 4" Media filter sizes ?

[mixer440]

From my own unscientific survey, it seems that the 20x20x4" one are most obtainable at the usual hardware stores. Then maybe 16x20 and 16x25 ?????

[jtrammel]

20x25x4,16x25x4 and 20x20x4 are the most commom

[mixer440]

20x25x4,16x25x4 and 20x20x4 are the most commom

Thanks "j". Just wondering for a new system. 20x20 may not fit with existing return and furnace, but installer said probably 16x25 or 16x20 for the 4". Interestingly, one hardware store I called said that the 4" filters are either slightly under 4" or about 4 3/16". So is the typical installed filter cabinet/holder going to accommodate these differences ?

[RyanHughes]

Thanks "j". Just wondering for a new system. 20x20 may not fit with existing return and furnace, but installer said probably 16x25 or 16x20 for the 4". Interestingly, one hardware store I called said that the 4" filters are either slightly under 4" or about 4 3/16". So is the typical installed filter cabinet/holder going to accommodate these differences ?

If you search online there are typically generic replacement media filters that will fit your cabinet. Some may fit better than others, so it's important to look at the "true" dimensions and compare them to the OEM replacement filter.

[jtrammel]

Yes, some are nominally 4" (~3 3/4") or 5" (~4 1/2")