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Filter Replacement Access

FFU Type

Terra Part #PriceShips in
115 VPowder-Coated Steel2'x4'HEPATop SideDuctless 6601-24A-HV 77029 $1,4471-3 Days2
120 VPowder-Coated Steel2'x2'HEPARoom-Side w/ Dust Collector PanDuctless 6601-22B-HVR 77262 $1,4471-3 Days3
120 VPowder-Coated Steel2'x3'HEPARoom-Side w/ Dust Collector PanDuctless 6601-23B-HVR 77264 $1,4471-3 Days4
120 VPowder-Coated Steel2'x3'HEPATop SideDuctless 6601-23-HV 56381 $1,4471-3 Days5
120 VPowder-Coated Steel2'x3'ULPATop SideDuctless 6601-23-UV 56384 $1,6071-3 Days6
120 VPowder-Coated Steel2'x4'HEPARoom-Side w/ Dust Collector PanDuctless 6601-24B-HVR 77266 $1,4471-3 Days7
120 VPowder-Coated Steel2'x4'HEPATop SideDuctless 6601-24-HV 56380 Request Quote5-9 Days8
120 VPowder-Coated Steel2'x4'ULPATop SideDuctless 6601-24-UV 56383 $1,6071-3 Days9
120 VStainless Steel2'x4'HEPATop SideDuctless 6601-24-HVSS 68732 $2,2731-3 Days10
120 VStainless Steel2'x4'ULPATop SideDuctless 6601-24-UVSS 68736 $2,4221-3 Days11
230 VPowder-Coated Steel2'x2'HEPARoom-Side w/ Dust Collector PanDuctless 6601-22B-HVR-220 77263 $1,5921-3 Days12
230 VPowder-Coated Steel2'x3'HEPARoom-Side w/ Dust Collector PanDuctless 6601-23B-HVR-220 77265 $1,5921-3 Days13
230 VPowder-Coated Steel2'x4'HEPARoom-Side w/ Dust Collector PanDuctless 6601-24B-HVR-220 77267 $1,5921-3 Days14
240 VPowder-Coated Steel2'x2'HEPATop SideDuctless 6601-22-HV-220 59317 $1,5921-3 Days15
240 VPowder-Coated Steel2'x2'ULPATop SideDuctless 6601-22-UV-220 59318 $1,6071-3 Days16
240 VPowder-Coated Steel2'x3'HEPATop SideDuctless 6601-23-HV-220 59319 $1,5921-3 Days17
240 VPowder-Coated Steel2'x3'ULPATop SideDuctless 6601-23-UV-220-CE 59326 $1,9151-3 Days18
240 VPowder-Coated Steel2'x4'HEPATop SideDuctless 6601-24-HV-220 59321 $1,5921-3 Days19
240 VPowder-Coated Steel2'x4'ULPATop SideDuctless 6601-24-UV-220 59322 $1,6071-3 Days20
240 VPowder-Coated Steel2'x2'HEPATop SideDuctless 6601-22-HV-220-CE 59323 $1,7551-3 Days21
240 VPowder-Coated Steel2'x2'ULPATop SideDuctless 6601-22-UV-220-CE 59324 $1,9891-3 Days22
240 VPowder-Coated Steel2'x4'HEPATop SideDuctless 6601-24-HV-220-CE 59327 $1,7551-3 Days23
240 VPowder-Coated Steel2'x4'ULPATop SideDuctless 6601-24-UV-220-CE 59328 $1,9151-3 Days24
120 VPowder-Coated Steel2'x3'HEPATop SideDuctless 6601-23A-HV 77047 $1,4471-3 Days25
Filter Replacement Access
FFU Type
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:
Item is in stock and ready for immediate shipping
Free shipping in contiguous USA
Custom-configured product: Terra will quote.
Custom-configured product: Terra will quote.
Select a product line for product summary

Product Details

• Exhaust flow fan filter units convert any room into a negative pressure isolation/containment room

• Filtered exhaust system also ideal for containing dust generated during maintenance or construction

• Mounts into ceiling bay to remove sub-micron particles and provide safe exhaust

• Medical grade filters are leak tested in accordance with IEST standards and meet UL 900

• PSC variable speed motor provides precise, fully adjustable airflow control

• Low-profile design is ideal for rooms with limited ceiling space.

• 1/4-20 UNC threaded inserts on corners allow suspension by guy-wires.

• Optional all-304 stainless steel BioSafe® housing, filter face grille, filter frame and impeller ensure optimal cleanliness and stand up to alcohol and other cleaning agents.

High Efficiency Particulate Air (HEPA) Filter: 99.99% efficient at 0.3µm particle diameter.

Ultra-Low Particulate Air (ULPA) Filter: </span>99.999% efficient at 0.12µm particle diameter.

• Backward-curved fan optimizes airflow efficiency.

• Removable yellow power cord with 4-pin connector provides easy installation to Terra cleanrooms (connector may be used with an optional wall plug adapter; or may be removed entirely to hard-wire the FFU).

• Optional duct collar attachment allows connection to ducting for safe exhaust outside of room.

• FDA-approved silicone sealant without harmful chemicals seals inside housing to prevent air leakage.

• RSR designs allow quick and safe Bag-in/Bag-out (BIBO) filter replacement from the inside of the room for contact-free removal of filters with potentially hazardous airborne contaminants. Because it eliminates the need for roof access or breaching the cleanroom, an RSR model also greatly reduces maintenance time and related costs.


• (1) MERV 7 pre-filter (30% ASHRAE rated)

See performance data and submittal sheets for additional information.

Optional Accessories:

Power plug adapter

Stainless steel surface mount frame for installing FFU in ceiling without T-grid

12” ducted inlet connection adapter

Replacement filters

Filter replacement alarm

Eye bolt package for cable suspension

Control panel with night mode switch and power distribution modules

All filter sales are final; returns for this item cannot be accepted

Marks & Listings: CE, UL, ULC

Fan Filter Units

  • Terra Universal WhisperFlow® Filter Fan Units Terra Universal WhisperFlow® Filter Fan Units
  • COVID-19 Contamination Control Products by Terra Universal
Terra Universal WhisperFlow® Filter Fan Units

Features & Benefits

Features & Benefits

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
HEPA/ULPA filtration diagram with examples of filtered contaminants

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.

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

COVID-19 Infection Control

Terra’s in-stock ceiling-mounted reverse-flow ducted filter fan units convert any space into a negative pressure isolation room

Dust Collector Pan Helps Prevent Contaminants from Re-Entering Cleanroom

Collector pan accumulates dust particles that dislodge from the HEPA filter, preventing contaminants from re-entering the cleanroom. Collector pan integrates with bag-in/bag-out (BIBO) systems and is easily removed for cleaning or maintenance.

Complete Project Transparency

Terra is dedicated to complete transparency on project status, shipment tracking, and installation scheduling

Wide Selection of Global Shipping Options

Terra offers a broad range of global shipping services including door-to-door and white glove delivery

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

Catalog of CE-Marked Products

Terra offers over 1,700 CE-marked products configured for international voltage requirements

Available Accessories

Popular Accessories

For a full list of accessories, select a product then click Choose Accessories on that product page.
  • 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).
  • 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.
  • Stand for Cleanroom Fan Filter Unit
    Powder coated steel Fan Filter Unit stand supports up to two Fan/Filter Units for horizontal-flow applications (order FFU separately)
  • 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

On a tight schedule? Choose FasTrak 24/7 Priority Service to help meet your critical schedule for Terra-manufactured products, either before or after your order is placed.*

  • FasTrak 24/7 provides a 24/7 commitment to meet the shipping date YOU specify, regardless of quoted lead times.
  • FasTrak 24/7 assigns a dedicated production team plus a dedicated senior expeditor working three shifts to meet your delivery specification.
  • FasTrak 24/7 guarantees* to meet the agreed-to specified ship date.

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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