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Filter Replacement Access

Full Seam Welded

Terra Part #PriceShips in
120Powder-Coated Steel2'x3'HEPARoom-SideNo 6601-23-HRS-EC 63076 $1,7820-2 Days2
Only 1 left in stock
120Stainless Steel2'x2'ULPARoom-SideYes 6601-22B-URSS-EC-LT 79254 $4,7065-9 Days3
120Stainless Steel2'x2'ULPARoom-SideNo 6601-22B-URSS-EC 73539 $3,4871-3 Days4
18 in stock
120Stainless Steel2'x2'ULPATop SideNo 6601-22A-USS-EC 72879 $3,6351-3 Days5
12 in stock
120Stainless Steel2'x4'ULPARoom-SideYes 6601-24B-URSS-EC-LT 79295 $5,1761-3 Days6
In stock soon
120Stainless Steel2'x4'ULPARoom-SideNo 6601-24B-URSS-EC 73541 $3,4871-3 Days7
17 in stock
120Stainless Steel2'x4'ULPATop SideNo 6601-24A-USS-EC 72946 $3,6351-3 Days8
79 in stock
120Stainless Steel2'x3'HEPARoom-SideNo 6601-23A-HRSS-EC 70982 $3,3341-3 Days9
Clearance Only 1 left in stock
120Stainless Steel2'x3'ULPARoom-SideYes 6601-23B-URSS-EC-LT 79274 $4,7065-9 Days10
120Stainless Steel2'x3'ULPARoom-SideNo 6601-23B-URSS-EC 73540 $3,1705-9 Days11
120Stainless Steel2'x3'ULPATop SideNo 6601-23A-USS-EC 72892 $3,6351-3 Days12
12 in stock
120Powder-Coated Steel2'x2'HEPARoom-SideNo 6601-22B-HR-EC 72770 $2,1971-3 Days13
26 in stock
120Powder-Coated Steel2'x2'HEPATop SideNo 6601-22A-H-EC 72775 $1,7851-3 Days14
74 in stock
120Powder-Coated Steel2'x2'ULPARoom-SideNo 6601-22B-UR-EC 72774 $2,1761-3 Days15
Only 3 left in stock
120Powder-Coated Steel2'x2'ULPATop SideNo 6601-22A-U-EC 72836 $2,1061-3 Days16
In stock soon
120Powder-Coated Steel2'x4'HEPARoom-SideNo 6601-24B-HR-EC 72936 $2,3041-3 Days17
156 in stock
120Powder-Coated Steel2'x4'HEPATop SideNo 6601-24A-H2-EC 72939 $1,9455-9 Days18
120Powder-Coated Steel2'x4'ULPARoom-SideNo 6601-24B-UR-EC 72938 $2,1761-3 Days19
In stock soon
120Powder-Coated Steel2'x4'ULPATop SideNo 6601-24A-U-EC 72945 $2,1061-3 Days20
25 in stock
120Powder-Coated Steel2'x3'HEPARoom-SideNo 6601-23B-HR-EC 72881 $2,1561-3 Days21
21 in stock
120Powder-Coated Steel2'x3'HEPATop SideNo 6601-23A-H-EC 72884 $1,7851-3 Days22
52 in stock
120Powder-Coated Steel2'x3'ULPARoom-SideNo 6601-23B-UR-EC 72883 $2,1761-3 Days23
17 in stock
120Powder-Coated Steel2'x3'ULPATop SideNo 6601-23A-U-EC 72891 $1,9151-3 Days24
20 in stock
120Powder-Coated Steel2'x2'HEPATop SideNo 6601-22A-H-EC-CA 72776 $1,8981-3 Days25
Only 5 left in stock
120Powder-Coated Steel2'x3'HEPATop SideNo 6601-23A-H-EC-CA 72885 $1,8981-3 Days26
Only 7 left in stock
120Powder-Coated Steel2'x4'HEPATop SideNo 6601-24A-H-EC 72940 $1,7851-3 Days27
384 in stock
120Powder-Coated Steel2'x4'HEPATop SideNo 6601-24A-H-EC-CA 72941 $1,8981-3 Days28
27 in stock
Filter Replacement Access
Full Seam Welded
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.
Select a product line for product summary
Product Details
  • EC brushless motors for quiet, energy-efficient operation and infinitely variable speed control
  • Provides much wider flow range, 110 to 1117 CFM, ideal for applications with high static pressure
  • Connect to automatic smart console for centralized fan control and cleanroom pressure balancing
  • Low-heat and low-noise production only 40 dBA, measured 12" from filter face @ 90 FPM
  • Minimize cleanroom service downtime with room-side-replaceable (RSR) fan filter units
  • Ships in 120V configuration. Can be easily be reconfigured to 230V
  • WhisperFlow® baffling technology supports uniform velocity across the face of the filter for truly laminar air flow
  • Choose from powder-coated steel or all stainless steel housing
  • Choose from room-side-replaceable or top-side-replaceable filter
  • 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
  • Forward-curved centrifugal fans
  • Generate less vibration, noise and heat than standard FFUs with AC motors
  • Ethernet ports for remote monitoring and control
  • Models with all-stainless steel housing and filter frame meet strictest cleanroom requirements
  • Includes a Merv 7 pre-filter and main HEPA or ULPA filter to help meet ISO cleanliness standards
  • HEPA filters remove particles down to 0.3 µm at 99.99% efficiency
  • ULPA filters remove particles down to 0.12 µm at 99.999% efficiency
  • Complies with Title 24 and ErP 2015 Directive
  • Brushless EC motors have internal micro-processors
  • Internal baffling plate and diffuser panel provide quiet uniform air flow across the filter face
  • 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.

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

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.

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).

Smart Fan Filter Unit with EC Motor

Smart WhisperFlow® Fan Filter Units are quiet, energy-efficient and easily adjustable, either manually or via automatic smart console, for centralized fan speed control and cleanroom pressure balancing.

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.
  • 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.
  • 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).
  • 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.
  • Challenge Port; for Fan/Filter Unit

    Challenge port for Fan/Filter Units simplifies filter leak testing and connection of Filter Backpressure Alarm (shown mounted on SS FFU, order separately).
  • 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.
  • 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).
  • 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.
  • 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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