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ISO Class


Terra Part # Price Ships in
120 V Powder-Coated Steel 2'x2' HEPA Top Side ISO 5 No 6601-22-H-LP 76564 $1,333 0-2 Days 2
Only 1 left in stock
120 V Powder-Coated Steel 2'x3' HEPA Top Side ISO 5 No 6601-23-H-LP 76563 $1,466 1-3 Days 3
Quick Ship+ 31 in stock
120 V Powder-Coated Steel 2'x4' HEPA Top Side ISO 5 No 6601-24-H-LP 76562 $1,333 0-2 Days 4
13 in stock
120 V Powder-Coated Steel 16" x 24" HEPA Top Side ISO 4 Yes 6601-1624A-H-LP 80864 $1,443 0-2 Days 5
Only 10 left in stock
120 V Powder-Coated Steel 16" x 36" HEPA Top Side ISO 5 Yes 6601-1636B-H-LP 82917 $1,443 0-2 Days 6
Only 3 left in stock
120 V Powder-Coated Steel 16" x 48" HEPA Top Side ISO 5 Yes 6601-1648A-H-LP 80862 $1,443 0-2 Days 7
Only 5 left in stock
120 V Stainless Steel 1'x1' HEPA Top Side ISO 5 Yes 6601-11A-HSS-LP 80865 $1,506 0-2 Days 8
13 in stock
120 V Stainless Steel 2'x2' ULPA Top Side ISO 4 Yes 6601-22A-USS-LP 80861 $2,567 5-5 Days 9
120 V Stainless Steel 2'x3' ULPA Top Side ISO 4 Yes 6601-23A-USS-LP 80860 $2,567 5-5 Days 10
120 V Stainless Steel 2'x4' ULPA Top Side ISO 4 Yes 6601-24A-USS-LP 80859 $2,567 5-5 Days 11
220 V Powder-Coated Steel 2'x2' HEPA Top Side ISO 5 No 6601-22-H-LP-220 81022 $1,392 5-5 Days 12
220 V Powder-Coated Steel 2'x3' HEPA Top Side ISO 5 No 6601-23-H-LP-220 81023 $1,392 5-9 Days 13
220 V Powder-Coated Steel 2'x4' HEPA Top Side ISO 5 No 6601-24-H-LP-220 81019 $1,531 0-2 Days 14
Quick Ship+ 35 in stock
Filter Replacement Access
ISO Class
Item ordered before. Click on bagde to see the order.

Up to 30-day trial periods, free return shipping and on-site training available for qualified equipment.

Request demo from your product specialist or add note to your order or quote request.

Some ship in:
Usually Ships in:
Free shipping in contiguous USA
Custom-configured product. Contact Terra by phone, chat or email for a project-specific quote.
Custom-configured product. Contact Terra by phone, chat or email for a project-specific quote.
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Product Details
Product Details
  • Available ISO Ratings: ISO 5, ISO 6, ISO 7, ISO 8
  • Low profile 8"H fan filter units are ideal for cleanrooms with restricted height areas
  • High Efficiency Particulate Air (HEPA) Filter: 99.99% efficient at 0.3µm particle diameter
  • Variable speed control dial for precise air flow control
  • FDA-approved silicone sealant prevents air leakage without harmful outgassing chemicals
  • Backward-curved fan for optimized efficiency
  • Low profile fan filter units are ideal for cleanrooms with restricted height areas
  • Stands 8"H compared to 13.5"H on standard designs
  • Variable speed control dial to adjust air flow
  • Meets IEST Recommended Practices
  • HEPA (High-Efficiency Particulate Air) filters are rated 99.99% efficient at removing particles @ 0.3 microns
  • Provides years of no-maintenance, 24/7 operation (depending on air quality)
  • Motor: 1/4 HP Direct drive, thermally protected with automatic overload reset
  • Backward-curved centrifugal fans

Unit of Measure: of 1

Marks & Listings: UL, ULC

Fan Filter Units

  • Terra Universal WhisperFlow® Filter Fan Units Terra Universal WhisperFlow® Filter Fan Units
Terra Universal WhisperFlow® Filter Fan Units
Features & Benefits

Features and Benefits

Learn More: Filter Fan Units Prevent Infection

Did You Know?
HEPA/ULPA Filters Do More Than Meet ISO Requirements - they also prevent infection.

Most cleanroom professionals understand that HEPA and ULPA filters capture contaminants that degrade particle-sensitive samples. But they also help remove bacteria, mold spores, and many viruses that contribute to a host of infections.

Most common bacteria are contained by the 0.3-micron pore size of high-efficiency particular air (HEPA) filters. Ultra-Low Penetration Air (ULPA) filters, which are rated 99.999% efficient at retaining particles of 0.12 microns and larger in diameter, capture ultra-fine contaminants, including many large viruses and mold spores.

These filters also remove aerosol-born pathogens - germs that hitch a ride on larger particles and liquid droplets that are captured in a HEPA or ULPA filter. HEPA- or ULPA-based Fan/Filter Units (FFUs) thus can play an important role in infection prevention in surgical theaters, ICUs and other medical settings.

Additionally, HEPA filters can help filter pollen, tiny insects, bacteria, mold, and other fungal spores that might be present during plant tissue culture or cannabis production. Contaminants such as these can find a way in via personnel or normal HVAC units and can blight crops and reduce yields. HEPA Filters help increase crop yields, pass inspection/meet regulations, and reduce contamination.

Here is a list of common human pathogens that HEPA/ULPA filters capture and remove from circulation:

Pathogens: Bacteria and Diseases
  • SARS-CoV-2: Coronavirus (COVID-19)
  • Escherichia coli: Gastrointestinal infection
  • Bacillus anthracis : Anthrax
  • Aspergillus brasiliensis: Sinus infections
  • Francisella tularensis: Tularemia
  • Bordetella pertusis : Whooping cough
  • Mycoplasma pneumoniae: Pneumonia
  • Chlamydia pneumoniae: Bronchitis
  • Clamydia psittaci : Psittacosis
  • Klebsiella pneumoniae: Opportunistic infections
  • Haemophilus influenzae : Meningitis
  • Coxiella burnetii: Q fever
  • Pseudomonas aeruginosa: Opportunistic infections
  • Actinomyces israelii: Actinomycosis
  • Legionella pneumophila: Legionaire's disease
  • Thermoactinomyces sacchari: Farmer's lung
  • Alkaligenes: Opportunistic infections
  • Streptococcus pyogenes: Scarlet fever
  • Mycobacterium Tuberculosis: Tuberculosis

Mini 12”x12” FFU for Small Enclosures

Terra’s Mini HEPA FFU removes airborne contaminants to enhance contamination protection in small enclosures.
The LED status indicator glows continuously when the FFU is plugged in and turned on to confirm the system is operational. Variable speed control dial allows for precise air flow control. Durable and corrosion resistant 304 stainless steel housing resists alcohol-based cleaning agents.

Mini FFU Size Comparison

The Mini FFU fits a compact 12”x12” footprint. Perfect for small enclosures such as storage cabinets, gloveboxes, and pass-through chambers. Single pass HEPA-filtration adds an extra layer of protection against particle and microbe contamination.

Diffuser Panel Promotes Air Flow Uniformity and Protects Filter Integrity

Unlike other manufacturers, Terra’s FFUs include a unique perforated panel beneath the filter, acting as a shower head, to guarantee filter protection and laminar air flow uniformity, which prevents localized air swirling, particle build-up and turbulence.

Low Profile FFU Design Only 8-Inches Tall

Low profile fan filter units are ideal for cleanrooms with height constraints. They stand 8 inches tall, compared to a standard FFU that stands 13.5 inches tall. The variable speed control dial allows for precise air flow control.

Protect Against Contaminants and Pathogens

HEPA and ULPA filters help capture many bacteria, viruses (COVID-19), and mold spores that contribute to a host of infections for both humans and plant/animal tissue cultures

Long Running FFU Motors

Terra’s filter fan unit motors are rated for 5 years of continuous, 24/7 operation, if the HEPA filters are consistently replaced. To accurately monitor your HEPA filter’s saturation levels, purchase Terra’s audible and visual filter replacement alarm system.

Clean and Durable Powder Coat Finish

Terra’s signature white powder coat finish provides a high quality, durable barrier to protect against corrosion, plus a clean and attractive aesthetic. The advanced heat-fused formulation exceeds ASTM and ISO paint standards to resist chipping, scratching, fading, and wearing.

Network of International Reps

Terra employs an international network of more than 20 local sales reps trained to provide comprehensive service on Terra's complete catalog of products

Wide Selection of Global Shipping Options

Terra offers a broad range of global shipping services including door-to-door and white glove delivery. Each product is safely packaged in a heat-treated wooden crate that meets international shipping standards.

Products Compliant With Your ISO Rating

High-capacity, durable, ISO-compliant system rated for thousands of operating hours.
Available Accessories
Popular Accessories
For a full list of accessories, select a product then click Choose Accessories on that product page.
  • Energy-Efficient Lighting

    Energy-efficient LED lighting panels and strips help to lower electrical costs and minimize heat build-up in temperature-controlled environments.
  • Cord Adapter, MIN4 PL to 16AWG Power Cord for Terra Fan/Filter Unit

    Four-pin power cord adapter for fan/filter unit allows connection to standard 120VAC/60Hz power receptacle.
  • Filter Replacement Alarm

    The filter replacement alarm monitors filter backpressure and issues an alarm when filter needs replaced (requires selection of fan filter unit with challenge port, order separately).
  • Challenge Port for Fan Filter Unit

    Challenge port for Fan/Filter Units simplifies filter leak testing and connection of Filter Backpressure Alarm (shown with optional pressure gauge; must be ordered with FFU).
  • Replacement Filters

    Purchase replacement filters ahead of time to prevent costly operational interruptions and avoid damage to fan blowers caused by excessive backpressure from long overdue filter replacements.
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Manuals & Resources
Manuals & Resources

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  • FasTrak 24/7 provides a 24/7 commitment to meet the shipping date YOU specify, regardless of quoted lead times.
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Call for pricing. FasTrak service fees cover costs of additional services only, without additional profit.

 * Terra's FasTrak services limited guarantee: to ship on the ESD or date specified OR to refund up to 100% of FasTrak charges. This guarantee covers no direct, special, consequential or other damages and is strictly limited to up to 100% of the amount paid for FasTrak service. When a specified ship date is missed due to factors outside Terra's control (vendor performance, deliveries by shipping companies, etc.) and random factors such as accidents, the credit of up to 100% of the FasTrak 24/7 may not apply. FasTrak service requested after order placement will be quoted and accepted based on available time remaining before required ship date.

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