The Dri-Eaz HEPA 500 Carbon Pre-Filter (F397) is the optional activated carbon stage for the Dri-Eaz DefendAir HEPA 500 air scrubber. It equips the HEPA 500 to capture a wide variety of volatile organic compounds (VOCs), including soot and smoke, food odours, fumes from paint and paint thinners, sewer odours, and many other compounds.
No modification of the DefendAir is required — users simply place the carbon filter inside the cabinet in front of the HEPA filter and then re-secure the cover. The capacity of the carbon filter will vary widely depending on conditions, but it should be replaced when its effectiveness declines.
Important: For Existing HEPA 500 Machines
Legend Brands (Dri-Eaz) has discontinued the DefendAir HEPA 500 air scrubber but continues to supply its filters for existing machines. This filter is for owners of a HEPA 500 already in service. If you are buying a new air scrubber, see our Air Scrubbers range.
N.B. This filter is interchangeable with the XPOWER X-3400 Air Scrubber Carbon Filter.
Carbon Is for Odour, HEPA Is for Particles
Activated carbon adsorbs gases and odour molecules. It does not replace the HEPA filter, which captures the particles. On smoke and sewage jobs you want both: the carbon filter in the first position, the 2nd stage pre-filter behind it, and the HEPA filter last. Dri-Eaz describes the combination of carbon and HEPA filtration as especially effective against airborne soot and the odours it carries.
Features
- Captures a wide variety of volatile organic compounds (VOCs & MVOCs).
- Utilises Extruded Activated Carbon — carbon pellets, manufactured to a uniform size, to help ensure maximum airflow and maximum contact.
- Works by adsorption, carbon filtration’s natural ability to attract and hold gas and liquid molecules on its surface.
- 450 g of carbon has over 450,000 square metres of available surface — equivalent to the area covered by more than 60 football fields.
- Media: Utilises Extruded Activated Carbon — 1 kg of carbon pellets, manufactured to a uniform size, to help ensure maximum airflow and maximum contact.
- Filter Frame: Sturdy frame won't flex or leak.
A note on the two carbon figures above: the 450 g figure illustrates how much surface area activated carbon has; the carbon content of this filter is listed by CCW as 1 kg. Dri-Eaz does not publish the carbon weight of the F397, so treat 1 kg as CCW's figure until Dri-Eaz confirms it.
Specifications
| Brand | Dri-Eaz (Legend Brands) |
| Dri-Eaz part number | 100053 (F397) |
| CCW SKU | F397 |
| Fits | Dri-Eaz DefendAir HEPA 500 air scrubber |
| Also interchangeable with | XPOWER X-3400 Carbon Filter (X-3400-CF35), as listed by CCW |
| Media | Extruded activated carbon pellets |
| Carbon content | 1 kg (CCW figure — not published by Dri-Eaz) |
| Position in the machine | First filter position, ahead of the 2nd stage pre-filter and the HEPA filter |
| Sold as | Each (Dri-Eaz packs the F397 in fours in the US) |
| Dimensions | Not published by Dri-Eaz — measure the filter you are replacing if in doubt |
Choosing Your Filter Configuration
The DefendAir HEPA 500 can be configured with a variety of filters to suit your specific air scrubbing requirements. Use the chart below to find the best filtering configuration for the job at hand.
| Filtering application | First filter position | Second filter position | Final filter (HEPA) |
|---|---|---|---|
| Clean water loss air scrubbing. For a relatively clean environment. | (no filter necessary) | 2nd Stage Pre-Filter (F271 or AC36F2) | HEPA filter (F321) |
| Standard air scrubbing. For environments with higher particle loads, such as construction or remodelling sites. | 1st Stage Pre-Filter (F270) | 2nd Stage Pre-Filter (F271 or AC36F2) | HEPA filter (F321) |
| Odour control and air filtration. For the removal of volatile organic compounds (VOCs), food odours, fumes from paint and paint thinners, sewer odours, and many other noxious odours. | Activated Carbon Filter (F397) | 2nd Stage Pre-Filter (F271 or AC36F2) | HEPA filter (F321) |
Filter Descriptions
- 1st Stage Pre-Filter (F270). Synthetic fibre filter media rated at 10% efficiency. Captures the largest particles to help extend the life of the higher efficiency filters inside. More info.
- 2nd Stage Pre-Filter (F271 or AC36F2). Synthetic fibre filter media rated at 30% efficiency. Captures larger particles to help extend the life of the HEPA filter. More info. AC36F2 is CCW's aftermarket pre-filter — check its size against your machine before ordering.
- Activated Carbon Filter (F397). The activated carbon filter allows the removal of a wide variety of compounds, including volatile organic compounds (VOCs), food odours, fumes from paint and paint thinners, sewer odours, and many other noxious odours. Combining activated carbon filtration with HEPA filtration is especially effective in removing airborne soot particles and the odours they create. More info.
- HEPA filter (F321). The HEPA filter has an efficiency rating of 99.97% against 0.3-micron oily aerosol particles. The HEPA filtration standard was developed in the 1940s to control radioactive dust particles in U.S. nuclear laboratories. More info.
When to Change It
- Replace the carbon filter when odour starts passing through — its capacity varies widely with the job, so there is no fixed hour count.
- Dri-Eaz's guidance for all HEPA 500 filters: they are designed to be replaced after use to prevent cross-contamination. Do not clean and reuse them.
- After a sewage, fire or mould job, change the filters before the machine goes to the next site, and bag the used filters on site.
- Wear the PPE the job calls for when changing filters — the used carbon and HEPA hold what the machine removed from the air.
Frequently Asked Questions
Does the carbon filter replace the HEPA filter?
No. Carbon removes gases and odours; the HEPA filter (F321) captures particles. Run the carbon filter with a 2nd stage pre-filter and the HEPA filter, as shown in the chart.
Where does it go in the machine?
In the first filter position, inside the cabinet in front of the HEPA filter. No modification is needed — place it and re-secure the cover.
How long does it last?
It depends on the odour load. Heavy smoke or sewage will use it up far faster than light odour work. Replace it when odour starts coming through, and after any contaminated job.
Can I clean and reuse it?
No. Dri-Eaz says HEPA 500 filters are designed to be replaced after use to prevent cross-contamination, and are not to be cleaned and reused.
Will it fit my XPOWER X-3400?
CCW lists the F397 as interchangeable with the XPOWER X-3400 Carbon Filter. If you are unsure which filter your machine takes, send us the model and a photo of the filter you are replacing.
Is the HEPA 500 still made?
No. Legend Brands has discontinued the machine but still supplies its filters for existing units.
Related Products
- Dri-Eaz HEPA 500 Primary HEPA Filter (F321)
- Dri-Eaz HEPA 500 1st Stage Pre-Filter (F270)
- Dri-Eaz HEPA 500 2nd Stage Pre-Filter (F271)
- Aftermarket Pre-Filter for HEPA 500 & XPower X-3400 (AC36F2)
- Filters & Filter Bags
- Air Scrubbers
Not sure which filters your HEPA 500 needs for the job? Tell us the job type and we will confirm the configuration before you order.
