My filter is 4" thick and yours is 5". Will it fit?

This is a common question.

Air filters are typically sold using nominal dimensions, which are rounded or approximate measurements used for labeling and marketing. The actual dimensions of the filter can vary slightly and are determined by the manufacturer of your filter cabinet.

A great example is Honeywell filters. Honeywell was one of the pioneers of the media or deep pleat filter design, which is often labeled as 4" or 5" thick. However, the actual thickness of a Honeywell filter is 4-3/8", and in fact, none of the printed dimensions are exact. This is completely normal and expected.

Because Honeywell helped shape the standard for media filter cabinets, many other brands—such as Lennox, Bryant, and Carrier—designed their cabinets to fit Honeywell-style filters. So even if the dimensions seem off at first glance, the filters are likely the correct fit for your system.

We understand it can be confusing, but once you know the manufacturer of your filter cabinet, identifying the correct filter becomes much easier.

If you’re unsure or need help finding the right filter, click here to contact us—we’re happy to assist!

Best regards,