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Terra Part #PriceShips in
120Powder-Coated Steel2'x4'HEPARoom-Side 6601-24A-HR 68472 $1,5561-3 Days2
364 in stock
120Powder-Coated Steel2'x4'HEPATop Side 6601-24-H 49135 $1,2791-3 Days3
266 in stock
120Powder-Coated Steel2'x4'ULPARoom-Side 6601-24A-UR 68479 $1,8471-3 Days4
30 in stock
120Powder-Coated Steel2'x4'ULPATop Side 6601-24-U 49142 $1,4401-3 Days5
47 in stock
120Powder-Coated Steel2'x2'HEPARoom-Side 6601-22A-HR 68473 $1,5561-3 Days6
76 in stock
120Powder-Coated Steel2'x2'HEPATop Side 6601-22-H 49139 $1,2791-3 Days7
118 in stock
120Powder-Coated Steel2'x2'ULPARoom-Side 6601-22A-UR 68474 $1,8471-3 Days8
Only 4 left in stock
120Powder-Coated Steel2'x2'ULPATop Side 6601-22-U 49146 $1,4401-3 Days9
Only 6 left in stock
120Powder-Coated Steel2'x3'HEPARoom-Side 6601-23A-HR 68477 $1,5561-3 Days10
Only 4 left in stock
120Powder-Coated Steel2'x3'HEPATop Side 6601-23-H 49137 $1,2791-3 Days11
353 in stock
120Powder-Coated Steel2'x3'ULPARoom-Side 6601-23A-UR 68478 $1,8471-3 Days12
Only 2 left in stock
120Powder-Coated Steel2'x3'ULPATop Side 6601-23-U 49144 $1,4401-3 Days13
48 in stock
120Stainless Steel2'x4'ULPARoom-Side 6601-24A-URSS 68743 $3,2141-3 Days14
Only 2 left in stock
120Stainless Steel2'x4'ULPATop Side 6601-24-USS 62721 $2,8491-3 Days15
Only 5 left in stock
120Stainless Steel2'x2'HEPATop Side 6601-22-HSS 62711 $2,6591-3 Days16
Only 1 left in stock
120Stainless Steel2'x2'ULPARoom-Side 6601-22A-URSS 68739 $3,2141-3 Days17
Only 5 left in stock
120Stainless Steel2'x3'HEPATop Side 6601-23-HSS 62715 $2,6591-3 Days18
Only 6 left in stock
120Stainless Steel2'x3'ULPARoom-Side 6601-23A-URSS 68741 $3,2141-3 Days19
Only 4 left in stock
240Powder-Coated Steel2'x4'HEPARoom-Side 6601-24A-HR-220 68485 $1,8691-3 Days20
103 in stock
240Powder-Coated Steel2'x4'HEPATop Side 6601-24-H-220 49136 $1,4051-3 Days21
149 in stock
240Powder-Coated Steel2'x4'ULPARoom-Side 6601-24A-UR-220 68480 $2,0311-3 Days22
Only 3 left in stock
240Powder-Coated Steel2'x4'ULPATop Side 6601-24-U-220 49143 $1,5811-3 Days23
42 in stock
240Powder-Coated Steel2'x2'HEPARoom-Side 6601-22A-HR-220 68481 $1,8691-3 Days24
17 in stock
240Powder-Coated Steel2'x2'HEPATop Side 6601-22-H-220 49141 $1,4051-3 Days25
18 in stock
240Powder-Coated Steel2'x2'ULPARoom-Side 6601-22A-UR-220 68482 $2,0311-3 Days26
Only 2 left in stock
240Powder-Coated Steel2'x2'ULPATop Side 6601-22-U-220 49147 $1,5811-3 Days27
25 in stock
240Powder-Coated Steel2'x3'HEPARoom-Side 6601-23A-HR-220 68483 $1,8691-3 Days28
12 in stock
240Powder-Coated Steel2'x3'HEPATop Side 6601-23-H-220 49138 $1,4051-3 Days29
25 in stock
240Powder-Coated Steel2'x3'ULPARoom-Side 6601-23A-UR-220 68484 $2,0311-3 Days30
Only 10 left in stock
240Powder-Coated Steel2'x3'ULPATop Side 6601-23-U-220 49145 $1,5811-3 Days31
Only 8 left in stock
240Stainless Steel2'x4'HEPARoom-Side 6601-24A-HRSS-220 68748 $3,6591-3 Days32
Clearance Only 7 left in stock
240Stainless Steel2'x2'HEPATop Side 6601-22-HSS-220 62712 $2,9231-3 Days33
Clearance Only 2 left in stock
240Stainless Steel2'x3'HEPARoom-Side 6601-23A-HRSS-220 68746 $3,5331-3 Days34
Clearance Only 2 left in stock
240Powder-Coated Steel2'x2'ULPATop Side 6601-22-U-220-CE 49330 $1,9431-3 Days35
Clearance Only 4 left in stock
240Powder-Coated Steel2'x3'ULPATop Side 6601-23-U-220-CE 49332 $1,9431-3 Days36
Clearance Only 7 left in stock
120Powder-Coated Steel2'x4'HEPATop Side 6601-24-H2 51421 $1,4731-3 Days37
58 in stock
120Powder-Coated Steel2'x4'HEPATop Side 6600-22 63583 $1,2961-3 Days38
630 in stock
120Powder-Coated Steel2'x3'HEPATop Side 6601-23-H2 64781 $1,2791-3 Days39
Only 9 left in stock
120Powder-Coated Steel2'x2'HEPATop Side 6601-22-H-CA 68444 $1,4231-3 Days40
23 in stock
120Powder-Coated Steel2'x3'HEPATop Side 6601-23-H-CA 68445 $1,4231-3 Days41
Only 6 left in stock
120Powder-Coated Steel2'x4'HEPATop Side 6601-24-H-CA 68446 $1,4231-3 Days42
129 in stock
120Powder-Coated Steel2'x4'HEPATop Side 6601-24-H-NC 69177 $1,0541-3 Days43
463 in stock
120Powder-Coated Steel2'x4'HEPATop Side 6601-24-H-NU 81277 $1,2141-3 Days44
In stock soon
120Powder-Coated Steel2'x4'HEPATop Side 6601-24-H-NC-NU 81281 $1,0011-3 Days45
In stock soon
Filter Replacement Access
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.

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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.
Select a product line for product summary
Product Details
  • Cleanroom FFU provides avg velocity of 90+ FPM, airflow of 640+ CFM at Medium speed
  • Three speed settings (Low/Medium/High) simplify air balancing
  • Internal baffling plate and diffuser panel provide quiet and uniform air flow across the filter face
  • Quiet, low-vibration FFU design: only 49 dBA, measured 30" from filter face @ 90 FPM
  • Minimize cleanroom service downtime with room-side-replaceable (RSR) fan filter units
  • Room-side-replaceable filter units feature a Gel-sealed filter and easy-open clips to allow fast filter replacement from below without breaching the cleanroom ceiling
  • WhisperFlow baffling technology supports uniform air speed across the filter face, ensuring laminar airflow
  • Low-profile design allows cleanroom installation inside rooms with standard 9-foot ceilings
  • Meets IEST Recommended Practices
  • Models with all-stainless steel housing and filter frame meet strictest cleanroom requirements
  • Speak with a Terra sales associate for recommendations on quantities to meet specified requirements
  • Choose from cold rolled steel or all stainless steel housing
  • Choose from room-side-replaceable or top-side-replaceable filter
  • HEPA (High-Efficiency Particulate Air) filters are rated 99.99% efficient at removing particles ≥ 0.3 microns
  • ULPA (Ultra-Low Penetration Air) filters are rated 99.999% efficient at removing particles ≥ 0.12 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
  • Forward-curved centrifugal fans
  • 1/4-20 UNC threaded inserts on corners to allow suspension by guy-wires
  • MERV 7 pre-filter, 30% ASHRAE rated
  • Low-profile design is ideal for cleanrooms with limited ceiling space
  • Filters are leak tested in accordance with IEST standards and meet UL 900
  • See performance data and submittal sheets for additional information
  • Optional Accessories:
  •           Challenge port kit
  •           Power plug adapter
  •           Stainless surface mount frame for installing FFU in ceiling without T-grid
  •           12” ducted inlet connection adapter
  •           Replacement filter
  •           Filter replacement alarm
  •           Eye bolt package
  •           Ionizing bar
  •           Pre-filter safety cover, for CE conformance
  •           Control panel with night mode switch and power distribution modules

Unit of Measure: of 1

Marks & Listings: CE, 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

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.

Gel-Filled Channel on Room-Side Replaceable Filter

Gel-filled channel on room-side replaceable filter forms a tight seal against knife edge on fan housing, allowing fast, simple filter replacement from inside the cleanroom without the need for costly cleanroom shut-down.

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

Airflow Uniformity Improves Laminar Flow

Non-uniform air speeds produce turbulence that can recirculate particles into the air stream. Unique WhisperFlow® FFU baffling system and anodized diffuser plate promotes uniform laminar airflow to minimize turbulence and effectively carry away contaminating particles.

Full Range of Designs, Configurations!

WhisperFlow FFUs come in all styles: room-side replaceable, all-stainless steel, HEPA or ULPA filtration, EC energy-saving fans, reverse flow and more (shown: vapor filtration module with UV sanitation lamp).

WhisperFlow Quiet Operation Reduces Distracting Background Noise

Exposure to loud noises can lower the ability to focus on work and listen selectively, which may also lead to safety issues. Typical AC units can be annoyingly loud, measuring in the range of 70 dB (comparable to a vacuum cleaner). Terra’s WhisperFlow design produces far lower noise levels for a quiet environment comparable to a library. At 90 ft/min output, units measure under 50 dB from only 1 ft away (roughly 75% quieter than 70dB).

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.

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.
  • Energy-Efficient Lighting

    Energy-efficient LED lighting panels and strips help to lower electrical costs and minimize heat build-up in temperature-controlled environments.
  • Power Distribution Modules for Cleanroom FFUs and Lights

    UL-listed power distribution modules include all breakers, transformers and other electrical components for FFU/light connections; allows fast addition or relocation of FFUs or lights without the need for rewiring.
  • Ionizing Bar; 22"L, with Installation Kit, for 24 x 24 Fan/Filter Unit

    Ionizing bar, mounted to Fan/Filter Unit, provides a balanced stream of ions to the work area below to neutralize static charge and prevent electro-static discharge; 22" bar shown installed on 2' x 2' FFU.
  • Night Service Saves Energy, Extends Filter Life!

    Night service switch, shown mounted on Modular Hardwall Cleanroom panel, puts FFUs in low-energy mode during off-hours; saves 25% of fan operating costs and extends filter life.
  • 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).
  • 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.
  • FFU Mounting Frame; Stainless Steel

    Stainless steel Fan Filter Unit (FFU) mounting frame supports FFU on drywall or other rigid ceiling material, viewed from above ceiling panel (FFU not included).
  • Fan Filter Unit Control System

    Provides room-by-room monitoring and control of Smart WhisperFlow FFUs to maintain target pressure differentials for ISO classification; temperature, humidity and particle monitoring and data logging, as well as dynamic fan set-point control, also available.
  • Filter Covers Allow Ceiling Wash-Down

    Ceiling panel covers allow wash-down and sterilization of cleanroom walls and ceilings without damage to filter medium; requires BioSafe glass or stainless steel wall panels, which stand up to biocides.
  • 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).
  • Safely Mount FFU’s Above Floor for Horizontal Laminar Airflow

    The portable FFU base stand can be easily positioned to supply Class 100 horizontal laminar flow into a room or enclosure. It can also be positioned next to sensitive equipment/materials that are mounted close to the floor.
  • 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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