Specialty Laboratory Hoods

Features and Benefits

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Vertical vs. Horizontal Laminar Flow Hoods: A Scorecard for Specifiers

Laminar is derived from the Latin lamina, a thin sheet of material. When used to describe a laboratory hood, the term "laminar flow" refers to air exiting a filter in parallel layers that move at the same speed and in the same direction, vertically or horizontally across the enclosure. Any particles introduced in a laminar flow of air during a work process are predictably swept in the direction of the flow and removed from the enclosure, downstream of critical processes.

Disruption to laminarity results in turbulence, a randomized flow that suspends particles in eddies rather than removing them. Because they can remain in the system, carried by “second-pass” air that swirls around the critical work area, contaminants are deposited unpredictably, often with disastrous results.

Consideration #1: Footprint

Vertical laminar flow (VLF) hoods position the fan filter unit on top of the hood, a space-efficient design that accommodates most facilities as long as overhead clearance isn’t a problem. Horizontal laminar flow (HLF) hoods position the fan on the back of the hood, necessitating as much as 18” or more additional floor or bench space for fan, filter and make-up air flow. In a cleanroom or lab where space is at a premium, that difference alone could determine your choice. Footprint Advantage: VLF Hood

Consideration #2: Air Sash

VLF hoods often have an adjustable sash at the front of the hood to maintain the downward laminar air flow. HLF hoods are generally open at the front of the hood to ensure unrestricted horizontal air flow. The larger opening of an HLF hood makes placement of large objects and instruments easier when compared to a VLF hood although, without a sash to serve as a shield, chemical fumes or powders inside the work area may blow into the operator's face. Sash Advantage: VLF Hood (operator safety); HLF Hood (transferring large materials)

Consideration #3: Laminar Flow

Although both hoods are effective at sweeping particles from the hood, air eventually encounters obstacles that disrupt laminar flow. In most VLF hoods, the work surface creates turbulence, so critical processes must be performed above the surface to avoid contact with “second-pass” air that could contaminate a sensitive operation. Some VLF designs include a perforated floor with sub-surface plenum to reduce this obstruction, but these measures add cost. HLF hoods generally minimize this airflow disruption. However, large objects placed on the work surface can cause swirling or contaminate downstream materials, so critical operations should take place adjacent to the filter face. Laminar Flow Advantage: HLF Hood

We end with a tie; your working conditions will help you determine which of these advantages matter most in your operation.

Safety Alert: Under no circumstances should laminar flow hoods be used in the presence of hazardous materials. Use a fume hood or biological safety cabinet for safe biohazard containment.

Model	Horizontal Laminar Flow (HLF) Station	Vertical Laminar Flow (VLF) Station	ValuLine™ VLF Station	ValuLine Whisperflow Hood	Portable CleanBooth
Flow	Horizontal	Vertical	Vertical	Vertical	Vertical
Nominal Widths	7', 6', 4' (2.1 m, 1.8 m, 1.2 m)	8', 6', 5', 4' (2.4 m, 1.8 m, 1.5 m, 1.2 m)	8', 6', 5', 4' (2.4 m, 1.8 m, 1.5 m, 1.2 m )	6', 5 ', 4', 3 ', 2 ' (1.8 m, 1.5 m, 1.2 m, .9 m, .6 m)	6', 4' (1.8 m, 1.2 m)
Nominal Overall Depth and Height	44"D x 63"H (1118 mm x 1600 mm)	41"D x 90"H (1041 mm x 2286 mm)	41"D x 90"H (1041 mm x 2286 mm)	24”/30”D x 41”H (610/762 mm x 2286 mm)	30"D x 82"H (762 mm x 2083 mm)
Nominal Working Space	30"D x 28"H (762 mm x 711 mm)	27"D (686 mm); height depends on workbench used	27"D (686 mm); height depends on workbench used	24”/30”D x 23”H (610/762 mm x 584 mm)	24"D (610 mm); height depends on workbench used
Construction Material / Options	Powder coated steel frame exterior 304 Stainless steel interior	Powder coated steel 304 stainless steel Acrylic or SD PVC shield options	Powder coated steel 304 stainless steel Acrylic or SD PVC shield options	304 stainless steel frame 304 SS, acrylic or SD PVC panels	Powder Coated Steel Frame
Work Surface Options	Stainless steel work area Optional electropolished finish.	Workbench sold separately; many top materials available. 2-piece frame isolates fan vibration.	304 Stainless Steel work surface included	Placed on user-furnished bench (stands available)	Workbench sold separately; many top materials available. 2-piece frame isolates fan vibration.
Blower Type	Integrated Fan/Filter Unit	Integrated Fan/Filter Unit	Integrated Fan/Filter Unit	Integrated Fan/Filter Unit	Integrated Fan/Filter Unit
Air Flow,	7' (2.1 m) 6' (1.8 m) 4' (1.2 m)	8' (2.4 m) 6' (1.8 m) 5' (1.5 m) 4' (1.2 m)	8' (2.4 m) 6' (1.8 m) 5' (1.5 m) 4' (1.2 m)	6'(1.8 m) 5'(1.5 m) 4' (1.2 m) 3 ' (.9 m)	6' (1.8 m) 4' (1.2 m)
CFM (m³/hr)	1130 (1920) 960 (1632) 650 (1104)	1300 (2209) 960 (1632) 840 (1427) 650 (1104)	1300 (2209) 960 (1631) 840 (1427) 650 (1104)	960 (1632) 840 (1427) 650 (1104) 558 (948)	960 (1632) 650 (1104)
Filter Types	HEPA or ULPA	HEPA or ULPA	HEPA or ULPA	HEPA or ULPA	HEPA or ULPA
Prefilter	Washable Polyurethane Foam	Washable polyurethane Foam	Washable polyurethane Foam	Washable polyurethane Foam	Washable polyurethane Foam
Portability / Installation Access	Not portable	Not portable. Wider than standard door frame	Not portable. Wider than standard door frame	Portable	Portable: CleanBooth frame uses casters.
Front Sash Configuration Options	Take-up air slots and plenums on three sides of the work area	Motorized sliding shield (allows simplified disassembly and transport) Strip shield curtains Or no shield	Counterweighted sliding shield (disassembly requires technical capabilities) Strip shield curtains Or no shield	Tilt-Up	Uses softwall panel kits: vinyl, anti-static vinyl, or non-outgassing polyurethane
Lighting	LED	LED	LED	LED	Optional fluorescent lighting
Noise Level, Measured 30" (762mm) from filter face at 90 FPM (.46m/s)	<50 dBA	<50 dBA	<50 dBA	<50 dBA	<50 dBA
Airflow Monitor Options	Minihelic gauge monitors backpressure across filter	Includes touch screen controls with backpressure indicator	Optional: air velocity meter and differential pressure gauge for filter backpressure	Optional swing-vane anemometer	Optional: air velocity meter and differential pressure gauge for filter backpressure
Power Requirements	120 VAC, 50/60 Hz or 220VAC, 50 Hz	110 VAC, 50/60 Hz or 220VAC, 50 Hz	110 VAC, 50/60 Hz or 220VAC, 50 Hz	110 VAC, 50/60 Hz or 220VAC, 50 Hz	120 VAC, 50/60 Hz or 220VAC, 50 Hz
Price Range	$9,300 – $14,300+	$6,000 - $14,000+	$5,000 - $10,000+	$1500	$2,000 - $4,500+
Application Synopsis	Large working space Airflow design reduces turbullence Quiet, reliable fan/filter modules Differential pressure gauge monitors filters Clean, easy-to-sterilize internal surfaces	Large working space and overhead clearance Economical Quiet, reliable fan/filter modules Optional counterweighted shield requires overhead clearance for disassembly	Large working space and overhead clearance Economical Quiet, reliable fan/filter modules Optional counterweighted shield requires overhead clearance for disassembly	Portable Economical, variety of panel materials Quiet, reliable fan/filter modules Easy cleaning	Large working space and overhead clearance Economical Quiet, reliable fan/filter modules Portability

Critical Environment Solutions

Terra's mission is to help customers in highly regulated industries transform the world with critical environment solutions that improve health, safety, performance, and yields. These environments may comply with stringent UL, ISO, IEST, ASTM and OSHA standards and local requirements.

Dedication to Business Ethics

Terra is committed to conducting business according to the highest standard of professional ethics and conduct. To review Terra’s ethics code, please visit: https://www.terrauniversal.com/ethics-policy/

Top-Tier Clients

Terra’s key customers include some of the largest research labs, production facilities and universities in the world

Long-Standing Industry Expertise

For 45 years, Terra has served the life science, academic research, pharmaceutical, biotechnology, medical device, semiconductor and aerospace markets. We intimately understand the cGMP, GLP, ISO, ASTM , IEST and OSHA requirements.

Removable Rear Plenum for Exhaust or Recirculation

An optional adjustable rear plenum mounts on the back wall of a benchtop laminar flow hood to exhaust or recirculate air (flexible ducting not included). Rear exhaust helps minimize turbulence and optimize laminar airflow in the work area.

PCR Clean Workstations

Turnkey laminar-flow ISO 5 PCR Hoods are designed for cloning and amplifying RNA and DNA. They also include UV-C disinfection lamps and pipette shelves.

Polypropylene Laminar Flow Containment Hood

Provides a particle-free environment for work with sensitive materials

Specialty Laboratory Hoods

Labconco Protector ClassMate
Labconco Xpert Balance Enclosure – 8 ft
Labconco Xpert Balance Enclosure – 4 ft
Labconco Xpert Nano Ductless Exhaust Hood
PCR Workstation
Explosion-Proof WhisperFlow Hood
Terra Universal IQ-OQ Process

Labconco’s Protector ClassMate Series of fume hoods has a glass rear panel and sides for total visibility of the work area, ideal for educational labs | 3645-10A displayed Labconco Protector ClassMate Labconco’s Protector ClassMate Series of fume hoods has a glass rear panel and sides for total visibility of the work area, ideal for educational labs.

Labconco’s Xpert Balance Enclosures can be customized to provide additional workspace and conveniences, such as bulk API access and waste ports | 3644-55 displayed Labconco Xpert Balance Enclosure – 8 ft Labconco’s Xpert Balance Enclosures can be customized to provide additional workspace and conveniences, such as bulk API access and waste ports.

Labconco’s Xpert Balance Enclosures provide economical containment of potentially harmful powders or fumes during weighing operations | 3644-52 displayed Labconco Xpert Balance Enclosure – 4 ft Labconco’s Xpert Balance Enclosures provide economical containment of potentially harmful powders or fumes during weighing operations.

Labconco’s Xpert Nano Series of ductless exhaust hoods features an ULPA filtration system for the highest level of protection against nanoparticulates | 3644-57 displayed Labconco Xpert Nano Ductless Exhaust Hood Labconco’s Xpert Nano Series of ductless exhaust hoods features an ULPA filtration system for the highest level of protection against nanoparticulates.

Terra’s PCR Workstation features a built-in UV light for decontamination of the hood following DNA- and RNA-processing | 1692-94 displayed PCR Workstation Terra’s PCR Workstation features a built-in UV light for decontamination of the hood following DNA- and RNA-processing; availble in several materials.

Terra’s Explosion-Proof WhisperFlow Hoods feature a UL-listed stainless steel fan/filture unit and light | 1686-54C-30-SSE displayed Explosion-Proof WhisperFlow Hood Terra’s Explosion-Proof WhisperFlow Lertical Laminar Flow Hoods features a UL-listed stainless steel HEPA fan/filter unit with light, switch, and other sealed electrical components.

This video describes the IQ/OQ process for Equipment and Cleanrooms Terra Universal IQ-OQ Process This video describes the IQ/OQ process for Equipment and Cleanrooms

Technical Resources

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Laminar Flow and Fume Hoods FAQs

Laboratory hoods serve a number of critical purposes in the lab environment.

Product protection from particulate contaminants in the lab environment, including microbes

Such hoods, often called laminar flow workstations or clean benches, use a flow of HEPA-filtered air to prevent influx of viable and non-viable particles into the enclosure and to sweep away any contaminants generated by the work process.

Protection of personnel and lab environment from substances generated inside the enclosure

For fume containment, laboratory fume hoods use a ducted ventilation system that maintains negative pressure. Where ducting is impractical, ductless hoods are also available for removal of non-hazardous contaminants (fumes or particles), using either HEPA or activated carbon filters.

Protection of product, operator and environment

Biological safety cabinets combine aspects of both hood types: a laminar flow of micro-filtered air and negative-pressure containment of bio-hazard fumes.

Laminar Flow Hoods

Laminar flow hoods (also called laminar flow clean benches) force air through a HEPA or ULPA filter to create a clean work area free of nearly all contaminating particulates, including bacteria, mold spores and many viruses. These hoods use a vertical or horizontal airflow design. Both provide excellent protection of products from particulates and cross-contamination, but do not protect the operator or environment.

So why choose one over the other? Vertical laminar flow hoods (VLF Hoods) require less floor space, but more overhead clearance. In addition, a sash at the front of the VLF hood provides a barrier between air exiting the hood and the operator’s face. VLF hoods create turbulent air flow when air strikes the work surface, requiring sterile work to be performed above the work surface.

HLF hoods minimize air turbulence (and particle backflow) on the work surface except where equipment disrupts the horizontal airflow. However, they direct the airflow directly at the operator’s face and require more depth to accommodate placement of the fan filter unit at the rear of the hood.

Fume Exhaust Hoods

Laboratory fume hoods draw air from the environment through the opening of the hood, allowing environmental contaminants into the work area. Thus, lab fume hoods do not offer a sterile environment or product protection. Instead, chemical fume hoods are designed to protect the operator from dangerous or irritating fumes and powders generated from work performed inside the hood.

In ducted fume hoods and canopy fume hoods, air passes out of the hood through a duct leading to an in-house ventilation system that contains and/or neutralizes hazardous materials.

In ductless fume hoods, fans draw exhaust air through a series of filters that remove irritating substances before release back into the room. Since these filters are not 100% efficient in removing all substances, ductless fume hoods are not advised in the presence of biohazards; however, they provide a convenient, cost-effective solution for operations involving irritating but non-hazardous fumes in facilities where an in-house HVAC system cannot be accessed.

Biosafety Cabinets

Biological Safety cabinets combine design aspects of both laminar flow and fume hoods. Filtered air is directed downward onto the work surface and then travels into a plenum through openings on the front and sides of the hood. Depending on the classification of the biosafety hood, some percentage of air is recirculated through a HEPA filter while the rest is directed out of the hood through an exhaust system. Thus, biosafety cabinets offer operator, environmental and product protection.

These laboratory safety cabinets (sometimes called IV hoods or compounding hoods) are ideal when preparing sterile medications such as chemotherapeutic agents that may pose a risk to the operator.

BSCs, BSLs, and ISO Classes

When it comes to working with hazardous or potentially infectious material, protecting personnel must be the primary concern. However, offering personnel protection does not have to come at the cost of risking product integrity. Class II BSCs provide protection to both personnel and product simultaneously. They maintain an ISO class 5 clean work area for product manipulation, while ensuring that exhaust air is filtered and ducted out of the environment. Thus, a class II BSC is the ideal solution when working with moderately hazardous material and both personnel and product safety are required.

All Resources 3

Submittal 1

Catalog 1

Tech Resource 1

submittal [pdf]

Submittals and Product Data - WhisperFlow Fan Filter Units

Technical data submittals for Terra Universal fan filter units.

catalog [pdf]

Terra Universal Hoods Vol 8 #16

This mini-catalog features Terra's offerings for laminar flow hoods, fume hoods and biological safety cabinets, including options from both Terra and Labconco.

tech resource [pdf]

Chemical Compatibility Charts