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Furnace · Best-of

Best 4-Inch and 5-Inch Furnace Filter (Deep Media)

Bottom line

The best deep-media filter pairs a true, honestly labeled MERV with low airflow restriction and yearly replacement - it outperforms a 1-inch filter at the same MERV on both airflow and running effort.

If your system has a media cabinet, deep-media filters (4-inch and 5-inch) are the format to buy - and the technically right way to run high MERV. All that extra surface area means strong filtration with little drag on your airflow, and you swap them about once a year instead of every few months. The one requirement is that your air handler has a cabinet to take them.

How we score: We surface the 4-inch and 5-inch deep-media filters and rank them by overall score, which rewards honest MERV labeling and credits deep media for how little it restricts airflow.

  1. 16.0
    Aprilaire 213 (4-inch media, MERV 13)

    The Aprilaire 213 (4-inch media, MERV 13) is a 4-inch deep-media furnace filter rated MERV 13 on the standardized ANSI/ASHRAE 52.2 scale, which captures fine particles including smoke and many bacteria-size particles. It labels its true MERV with no proprietary scale. Its deep media keeps airflow restriction low even at this MERV. Replaced about 1 time a year, it runs roughly $65 per year.

    • True MERV (ASHRAE 52.2): MERV 13
    • Depth: 4 inch (deep media, low airflow restriction)
    • Annual filter cost: $65/yr
  2. 26.0
    Aprilaire 413 (4-inch media, MERV 13)

    The Aprilaire 413 (4-inch media, MERV 13) is a 4-inch deep-media furnace filter rated MERV 13 on the standardized ANSI/ASHRAE 52.2 scale, which captures fine particles including smoke and many bacteria-size particles. It labels its true MERV with no proprietary scale. Its deep media keeps airflow restriction low even at this MERV. Replaced about 1 time a year, it runs roughly $65 per year.

    • True MERV (ASHRAE 52.2): MERV 13
    • Depth: 4 inch (deep media, low airflow restriction)
    • Annual filter cost: $65/yr
  3. 36.0
    Honeywell FC100A1037 (4-inch media, MERV 11)

    The Honeywell FC100A1037 (4-inch media, MERV 11) is a 4-inch deep-media furnace filter rated MERV 11 on the standardized ANSI/ASHRAE 52.2 scale, which captures fine dust, pollen, and pet dander. It labels its true MERV with no proprietary scale. Its deep media keeps airflow restriction low even at this MERV. Replaced about 1 time a year, it runs roughly $39 per year.

    • True MERV (ASHRAE 52.2): MERV 11
    • Depth: 4 inch (deep media, low airflow restriction)
    • Annual filter cost: $39/yr
  4. 46.0
    Lennox Healthy Climate X6673 (5-inch media, MERV 11)

    The Lennox Healthy Climate X6673 (5-inch media, MERV 11) is a 5-inch deep-media furnace filter rated MERV 11 on the standardized ANSI/ASHRAE 52.2 scale, which captures fine dust, pollen, and pet dander. It labels its true MERV with no proprietary scale. Its deep media keeps airflow restriction low even at this MERV. Replaced about 1 time a year, it runs roughly $36 per year.

    • True MERV (ASHRAE 52.2): MERV 11
    • Depth: 5 inch (deep media, low airflow restriction)
    • Annual filter cost: $36/yr

FAQ

Do I need a special cabinet for 4-inch filters?
Yes - so check before you buy. Deep-media filters slot into a media-filter cabinet (Aprilaire, Honeywell, Lennox, and similar) at the air handler, not the standard 1-inch return-grille slot. If your system doesn't have that cabinet, a 4-inch filter won't fit.
Why is deep media better at high MERV?
It comes down to surface area. A 4-inch filter packs far more pleated media than a 1-inch panel, so it can hit MERV 13 while holding back your airflow much less - and last about a year instead of a few months. You get the filtration without the airflow penalty.

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