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Holmes · air purifier

Holmes HAP9423 replacement filter

Use part HAPF300AH. Interval not published by the maker.

The filter that fits

From the maker's archived page

Holmes aer1 HAPF300AH

aer1 HAPF300AH Allergen Remover Replacement Filter

Part number
HAPF300AHalso sold as HAPF300AH-U4
How many
1 per unit
How often
Interval not published by the maker

Holmes does not say how many filters this unit holds; check the filter slot before ordering more than one.

Buy aer1 HAPF300AH on Amazon

Opens an Amazon search for Holmes aer1 HAPF300AH. Check the listing says HAPF300AH.

See the sources

Does your exact model share this filter?

Holmes labels several versions of the HAP9423. Check the label on your unit.

  • HAP9423 takes HAPF300AH
  • HAP9423-UA same filter · Earlier retail code
  • HAP9423-UAH same filter · 2021 retail code (True HEPA listing)

Look-alike models that take a different filter

Other aer1 units (HAP242, HAP706, HAP9242) take the same aer1 filter family; the HAP759 console takes HAPF600 instead.

Other genuine options from Holmes

Variants and kits the maker sells for this model. Same fit, different media or packaging.

  • aer1 HAPF300AP True HEPA Allergen Performance-Plus Replacement Filter
    HAPF300AP · Find on Amazon
  • aer1 HAPF30AT HEPA-Type Total Air with Dust Elimination Replacement Filter
    HAPF30AT · Find on Amazon
  • aer1 HAPF30AO Odor Eliminator Replacement Filter
    HAPF30AO · Find on Amazon

Sources

Medium confidence: from an archived manufacturer page, a licensed brand store, or a live manufacturer page that names a sibling variant rather than this exact model. Each line is the page we read and the day we read it.

  • Which filter fits web.archive.org Maker's archived page checked Oct 1, 2026
    Holmes HAP9423-UA aer1 Tower Air Purifier ... For Replacement Filter Use aer1 Filter HAPF300AH-U4 (holmesproducts.com returns 403; archive.org copy of 2017-12-28)
  • Model variants web.archive.org Maker's archived page checked Oct 1, 2026
    Holmes aer1 Tower True HEPA Air Purifier with Air Ionizer and Visipure Air Filter Viewing Window (HAP9423-UHA) ... Model: HAP9423-UAH-2 (archive.org copy of 2021-10-26)
Show all 3 sources

Which filter fits

  1. web.archive.org Maker's archived page checked Oct 1, 2026
    Holmes HAP9423-UA aer1 Tower Air Purifier ... For Replacement Filter Use aer1 Filter HAPF300AH-U4 (holmesproducts.com returns 403; archive.org copy of 2017-12-28)
  2. web.archive.org Maker's archived page checked Oct 1, 2026
    aer1 HAPF300AHCS Allergen Remover Replacement Filter (archive.org copy of 2014-08-25)

Model variants

  1. web.archive.org Maker's archived page checked Oct 1, 2026
    Holmes aer1 Tower True HEPA Air Purifier with Air Ionizer and Visipure Air Filter Viewing Window (HAP9423-UHA) ... Model: HAP9423-UAH-2 (archive.org copy of 2021-10-26)