Koch Filter · BioMAX HEPA

Build Your BioMAX HEPA Filter

Configure a Koch BioMAX HEPA filter to your exact specification. We send the build directly to our Koch representative for confirmation, lead time, and pricing — typically back to you within one business day.

Section 889 / NDAA compliant W-9, COI & PO on request 1-business-day response
  1. 1 Face Size
  2. 2 Cellside
  3. 3 Media & Capacity
  4. 4 Separator
  5. 5 Sealant
  6. 6 Quantity & Submit

Face size 01

Pick a standard size code below, or enter a custom size. The first dimension is the height of the filter and the direction the separators run.

How to read a BioMAX size Quick guide to H × W × D and choosing depth

BioMAX sizes are written Height × Width × Depth in inches. The height direction matters because the corrugated separators inside the filter run vertically along that dimension — installing a filter sideways changes airflow performance.

BioMAX is built in two depths:

  • 5⅞″ depth (H10–H33) — standard mini-pleat. The most common choice. Lower initial cost, fits most existing housings.
  • 11½″ depth (H60–H83) — deeper construction with more media area. Higher dust-holding capacity and longer service life. Used where the housing supports the deeper filter.

Not sure which depth? Check the existing filter you're replacing, or measure the housing's filter slot from front face to back. If you only have a make/model of the AHU, include it in the notes at checkout and we'll confirm with Koch.

Quick start Tap a common configuration, then pick your size below

5⅞″ depth · standard mini-pleat (H10–H33)

11½″ depth · deep mini-pleat (H60–H83)

Need a custom size?

Koch builds BioMAX to exact specifications when standard sizes don't fit. Enter your dimensions below and we'll send the request directly to our Koch rep for a custom quote.

Cellside construction 02

The frame and flange material that holds the media pack. Sometimes called the "case" or "header."

How to choose a cellside DTF vs STF vs Pan vs Wood vs Headered explained
Koch BioMAX construction diagram showing cellside frame, media pack, and separator
BioMAX construction — cellside frame holds the pleated media pack with separators between each pleat.

Three factors decide cellside choice:

  • Flange type — DTF, STF, Pan, Wood, or Headered. This must match how the housing or holding frame grips the filter.
  • Material — galvanized steel is standard. 304 stainless steel for wash-down, food/pharma, or corrosive air. Aluminum where weight matters. Particle board for cleanroom or where metal contamination is forbidden.
  • Gauge — 18 ga is the BioMAX standard. 16 ga is heavier-duty for high-velocity or rough-handling applications.
Koch BioMAX wood and metal frame comparison
Wood (particle board) vs metal cellside frames — both supported in BioMAX.
DTF — Double Turn Flange

The frame is folded back on itself twice. The most common, most rigid construction. Default for nearly all standard housings.

STF — Single Turn Flange

Single-fold frame. Lighter and slightly less rigid than DTF. Used in housings designed specifically for STF.

Pan Style

The filter sits in a metal pan rather than having a flanged perimeter. For ducted plenum mounting and in-line installations.

Wood (Particle Board)

Used in cleanrooms, ceiling grid systems, and applications where metal can't be present. NFR is non-fire-rated; FR is fire-rated.

Non-Tested (Headered)

Header construction without efficiency testing — used as prefilters or final filters where efficiency certification isn't required.

Not sure? Look at the side of the filter you're replacing. A folded metal edge means DTF or STF (DTF is the most common). A flat metal pan means pan style. A wood frame means particle board. If you're stuck, just include a photo or the existing part number in the notes at checkout — we'll confirm with Koch.

Double Turn Flange — DTF

Single Turn Flange — STF

Pan Style

Wood

Non-Tested Filters

Non-tested headers (K, L, M) pair with sealant option 4 (Hotmelt) by Koch convention.

Sealant 05

The bond between the media pack and the cellside frame. The sealant is what guarantees no air bypasses the filter.

How to choose a sealant Driven by operating temperature — most builds use option 1 or 2

The sealant choice is driven almost entirely by operating temperature:

  • Polyurethane Foam (1) — the BioMAX standard for DTF and Wood cellsides. Operates up to ~180°F. Use this unless temperature dictates otherwise.
  • Solid Polyurethane (2) — Koch's standard for Pan Style and STF cellsides. Same temperature range as foam, but a denser pour. Will be auto-suggested if you select a Pan or STF cellside.
  • 500°F Silicone Gasket (3) — for elevated process temperatures: industrial ovens, paint booth bake stages, certain pharma sterilization environments.
  • Hotmelt (4) — used on non-tested headered filters. Auto-paired with K/L/M cellsides.
  • 750°F Rope Gasket (5) — for the highest temperature applications. Industrial process exhaust, kiln preconditioning, and high-temp containment.
Koch BioMAX high-temperature configuration with silicone or rope gasket sealant
BioMAX high-temperature build — silicone (500°F) or rope (750°F) gasket replaces standard polyurethane sealant for elevated-temp applications.

Not sure? Is the air going through this filter room temperature, warm, or hot? Room temperature → option 1 or 2 (the standards). If it's coming off an industrial oven, paint booth bake stage, kiln, or any process you'd describe as "hot," tell us roughly how hot and we'll spec the right gasket — 500°F silicone or 750°F rope.

Media & capacity 03

The two decisions here: how efficient the filter is at capturing particles, and how much air it can move at rated efficiency.

Efficiency tiers & capacity explained 95% DOP, true HEPA, ULPA — and Std vs HiCap
  • 95% DOP — captures 95% of 0.3-micron particles. Below true HEPA grade. Used as a final filter where HEPA isn't required, or as a high-grade prefilter protecting downstream HEPA.
  • 99.97% (true HEPA) — the standard HEPA grade. Captures 99.97% of 0.3-micron particles. Efficiency-tested at the factory.
  • 99.99% — higher-efficiency HEPA. Scan-tested with PAO at the factory, meaning every square inch is verified.
  • 99.999% (ULPA) — Ultra-Low Penetration Air. The highest grade Koch builds in BioMAX. Available in Pan Style configuration only. Scan-tested with PAO.
Std Capacity vs HiCap

At the same efficiency, the BioMAX comes in two airflow configurations:

  • Std Capacity — rated at standard face velocity. The most common spec. Default unless airflow is specifically high.
  • HiCap (High Capacity) — more media area packed into the same face size, allowing higher CFM at the same pressure drop. Used where the AHU pushes more air than a standard filter can handle.
Koch BioMAX HC high-capacity configuration with extended media pleat depth
BioMAX HC (High Capacity) — extended pleat depth packs more media area into the same face size, increasing CFM capacity at the same pressure drop.

Not sure? If you just need "a HEPA," that's 99.97% Std Capacity — the most common choice and what 90% of customers want. Pick HiCap only if your existing filter is labeled high-capacity or your AHU runs higher CFM than a standard filter is rated for. ULPA (99.999%) is for semiconductor, pharma fill-finish, and certain biosafety applications — if you need it, you'll know.

99.99% and above are scan-tested with PAO. 99.97% filters are efficiency-tested. 95% DOP filters are not tested. 99.999% only available in Pan Style configuration.

Separator 04

The corrugated material that holds each pleat of media apart from the next, keeping airflow channels open and preventing the media pack from collapsing.

When PVC-coated matters Standard aluminum covers most installs — when to upgrade

The separator sits between every pleat of HEPA media, exposed to whatever air is moving through the filter. In normal indoor air, standard aluminum is fine for the entire service life of the filter.

PVC-coated aluminum is specified when one of the following is true:

  • High humidity — sustained relative humidity above ~70%, condensing environments, or wash-down spaces
  • Salt air — coastal facilities, marine, naval applications
  • Chemical exposure — air carrying acids, bases, halogens, or process chemicals that attack bare aluminum
  • Specification call-out — many federal, military, and pharma specs require PVC-coated separators by default

Not sure? Standard aluminum is fine for normal indoor air — that covers most installations. Pick PVC-coated if your facility is government, military (especially Navy), pharma, or lab; if your spec sheet calls for it; or if your air is humid, salty, or carries chemicals. When in doubt, mention your application in the notes and we'll confirm.

Quantity & details 06

Tell us how many you need and where to send the quote. We'll forward the build to our Koch rep and reply with confirmation, lead time, and pricing.

Quote returned within one business day.