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Austin Air Replacement Pre-Filter (F400)

Austin Air Replacement Pre-Filter (F400)


Genuine Austin Air Permafilt Pre-Filter (F400) replaces the outer pre-filter that comes with Austin Air standard-size air purifiers. This is the large particle pre-filter that can be seen through the sides of the unit. Lasts for years if maintained. Available in black or white.  Package contains one (1) Permafilt Pre-Filter.

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MSRP: $34.00
Sale Price: $27.49

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Works with Models:
Austin Air Allergy Machine (HM405), Bedroom Machine (HM402), HealthMate (HM400), HealthMate Plus (HM450), and Pet Machine (HM410)

Genuine Austin Air Permafilt Pre-Filter (F400) replaces the pre-filter that comes with Austin Air standard-size air purifiers. Long-life pre-filter traps large-sized particles that can easily be seen with the eye during the first stage of Austin Air's multi-stage filtration process. In performing this role, the pre-filter helps to prolong the life of the inner filters, especially the HEPA filter. Pre-Filter lasts for years under normal operating conditions and with regular care.  Package contains one (1) Permafilt Pre-Filter.

Because it can be seen through the air cleaner's grille, choose the Black pre-filter for Black-Silver-Blue units or the White pre-filter for Sandstone-White units.


  • Austin Air Permafilt Pre-Filter (F400) captures large particles, like dust, hair, soot and pet dander
  • Protects life of HEPA and other inner filters
  • Lasts for years with proper care, under normal conditions
  • Designed to be vacuumed from outside of unit to avoid costly 3-month filter changes
  • Fits all standard-size Austin Air purifiers:
    • Allergy Machine (HM405)
    • Bedroom Machine (HM402)
    • HealthMate (HM400)
    • HealthMate Plus (HM450)
    • Pet Machine (HM410)

Care Instructions:

  • Clean the pre-filter when dirty, simply by vacuuming the outside grille of the air purifier with the brush attachment of your vacuum on a monthly basis to reduce surface buildup and prolong the life of the pre-filter.

  • The pre-filter can last for years with regular cleaning, although replacing annually is an option for the cleanest air. Either way, this pre-filter avoids regular filter changes often required with other air purifiers, for cost savings and long-term value.

Changing the Pre-Filter:

  • Please see Owner's Manual tab for full instructions on filter changes, including a one‐page quick reference sheet.

Click here to view the Austin Air Owner's Manual.

Click here for a one-page set of instructions on filter changes for the Austin Air.


Rated 5.00 out of 5 based on 2 reviews.

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The Austin Air Filter is the best room air cleaner I've ever found. Maintenance is so easy. The pre-filter needs to be changed every 6 months, and then I vacuum the main filter. I have 4 of these around the house (I have severe allergies) and 2 of them have already gone over their 5 year estimated lifetime. All other air filters make you change the pre-filter every 3 months and the main filters yearly - they are too expensive and it's too dirty a job, plus they don't work near as well as the Austin Air Filter.
I've had my Austin Air for years. It's a quiet running air cleaner compared to other HEPA cleaners, and it's easy to maintain. High quality. If it broke, I would go buy another one. I've had mine for over 10 years now, I think, and still running fine.