Exhaust Snorkels for Laboratories: Flexible Fume Extraction Explained

Marketing Manager

Not every fume-generating process needs a full fume hood. When you need localized extraction at a specific spot on your bench — for soldering, light chemistry, specimen processing, or laser cutting — an exhaust snorkel provides flexible, point-source fume capture without the cost and space requirements of a fume hood.

Exhaust snorkels (also called snorkel arms, fume extractors, or bench-top extraction arms) are articulating ductwork arms mounted above or beside workstations. They position a capture hood directly at the fume source and connect to the building’s exhaust system.

How Exhaust Snorkels Work

An exhaust snorkel consists of:

  1. Capture hood: A funnel-shaped inlet that draws in contaminated air from the work area
  2. Articulating arm: A jointed, flexible arm that allows the capture hood to be positioned in any direction
  3. Exhaust connection: Connects to ductwork leading to the building’s exhaust fan

The researcher positions the capture hood close to the fume source — ideally within 6–12 inches — and the exhaust system draws contaminated air away through the ductwork.

Types of Exhaust Snorkels

Standard (Original) Snorkels

Made from chrome-plated or powder-coated steel. Suitable for general-purpose fume extraction where chemical exposure is light — soldering, dust collection, odor removal.

Chemical-Resistant Snorkels

Constructed from polypropylene or other chemical-resistant plastics. Required when extracting corrosive acid fumes, solvent vapors, or any chemical that would damage standard steel construction. Essential for chemistry and pharmaceutical labs.

ESD-Safe Snorkels

Made from conductive materials that prevent static buildup. Required in electronics manufacturing, semiconductor labs, and environments with flammable or explosive atmospheres.

Read our detailed comparison: Chemical Resistant vs ESD vs Original Exhaust Snorkels

CFM Requirements

The right airflow (CFM) depends on the application and capture distance:

Application Recommended CFM Max Capture Distance
Soldering 50–75 CFM 6–8″
Light chemistry 75–150 CFM 8–12″
Moderate chemistry 150–250 CFM 10–15″
Heavy fume generation 250–400+ CFM 12–18″

For detailed CFM calculations, read our Exhaust Snorkel CFM Guide.

Installation Options

  • Ceiling-mounted: The most common configuration. Arm drops down from ceiling-mounted ductwork.
  • Wall-mounted: For labs where ceiling mounting isn’t practical.
  • Bench-mounted: Clamps directly to the workstation. Good for retrofits and portable setups.
  • Floor-standing: Mobile units with casters. No permanent installation needed.

Exhaust Snorkel vs. Fume Hood

Factor Exhaust Snorkel Fume Hood
Cost $500–$3,000 $3,000–$25,000
Space required Minimal (ceiling/wall mount) 4–8 feet of bench space
Protection level Localized capture only Full enclosure containment
Flexibility Repositionable to any bench location Fixed location
Best for Point-source, intermittent fumes Continuous chemical work

Important: Exhaust snorkels are NOT a replacement for fume hoods when full containment is required. They’re supplemental extraction for light-duty or intermittent fume sources. For heavy chemical work, always use a chemistry fume hood.

Frequently Asked Questions

How much does an exhaust snorkel cost?

Standard snorkels: $500–$1,200. Chemical-resistant: $800–$2,000. ESD-safe: $700–$1,500. Installation (ductwork connection) adds $500–$2,000 depending on complexity.

Do exhaust snorkels need ductwork?

Yes, for proper fume exhaust. The snorkel arm connects to ductwork routed to the building’s exhaust system. Some applications use carbon-filtered ductless units, but these are limited to specific chemicals.

How far can a snorkel reach?

Standard snorkel arms reach 3–5 feet from the mounting point. The articulating joints allow full 360° positioning within that radius. Longer arms are available for wider coverage.

Shop Exhaust Snorkels

We stock standard, chemical-resistant, and ESD-safe exhaust snorkels from Nederman and other leading manufacturers. Ships fast from our Utah warehouse.

Request a snorkel quote → or call (801) 999-8277.

Walk-In Fume Hoods: When Your Lab Needs Floor-Level Access

Marketing Manager

Standard benchtop fume hoods work for most chemistry applications, but what happens when your apparatus is too tall to fit inside a 48″ hood opening? That’s where walk-in fume hoods come in.

Walk-in fume hoods (also called floor-mounted fume hoods) have sashes that extend to the floor, creating a full-height opening that allows researchers to work with oversized equipment while maintaining complete fume containment.

When Do You Need a Walk-In Fume Hood?

  • Tall apparatus: Distillation columns, reflux setups, and reactor systems that exceed standard hood height
  • Floor-standing equipment: Drum handling, large-scale reactions, or equipment too heavy for a benchtop
  • Loading/unloading: Operations that require rolling equipment in and out of the hood
  • Pilot plant work: Scale-up reactions that need containment but use equipment too large for standard hoods
  • Perchloric acid work: Some perchloric acid setups require walk-in configurations with wash-down systems

Walk-In Fume Hood Specifications

Specification Standard Range
Width 48″ – 96″
Depth 30″ – 48″
Height (opening) 72″ – 84″
Face velocity 80 – 100 fpm
Exhaust volume 800 – 2,500 CFM
Sash type Vertical, horizontal, or combination

Sash Options

  • Vertical sash (full-height): Slides up to the full opening height. Provides maximum access when raised and maximum protection when lowered.
  • Horizontal sliding sash: Panels slide left and right. Allows access to portions of the hood while keeping the rest protected. Better energy efficiency.
  • Combination: Vertical sash with horizontal sliding panels. The most flexible option — vertical sash controls opening height while horizontal panels control which section is open.

HVAC Considerations

Walk-in hoods require significantly more exhaust capacity than standard benchtop hoods:

  • A standard 6′ benchtop hood exhausts approximately 800–1,200 CFM
  • A 6′ walk-in hood can require 1,500–2,500 CFM due to the larger face area
  • Your building’s air handling system must be evaluated before specifying a walk-in hood
  • Make-up air requirements increase proportionally

Our lab design team coordinates with your HVAC engineer to ensure proper airflow. Browse all fume hood types →

Frequently Asked Questions

How much does a walk-in fume hood cost?

Walk-in fume hoods range from $8,000–$25,000 for the hood unit. Installation including ductwork, services, and electrical typically adds $10,000–$25,000. Total installed: $18,000–$50,000+.

Can I convert a benchtop hood to walk-in?

No. Walk-in hoods are purpose-built with different structural, airflow, and sash designs. They must be specified from the start. However, some manufacturers offer convertible models with removable bench sections.

Are walk-in hoods less safe than standard hoods?

When properly designed and used, walk-in hoods provide equivalent containment. The key is maintaining adequate face velocity across the larger opening. This requires higher exhaust volumes and may require additional baffles for uniform airflow.

Get a Walk-In Fume Hood Quote

Tell us about your apparatus and application, and we’ll recommend the right walk-in hood size, sash type, and ventilation requirements.

Request a walk-in hood quote → or call (801) 999-8277.

Biological Safety Cabinets: Class I, II & III Explained

Marketing Manager

Biological safety cabinets (BSCs) are the primary containment devices used in laboratories that work with infectious agents, cell cultures, and hazardous biological materials. Unlike chemical fume hoods, BSCs protect the researcher, the environment, AND the work product simultaneously.

Understanding the differences between BSC classes is essential for selecting the right cabinet for your biosafety level and experimental requirements. Here’s a complete breakdown.

What Does a Biological Safety Cabinet Do?

A BSC uses HEPA-filtered airflow to create three types of protection:

  • Personnel protection: Inward airflow at the front opening prevents aerosols from escaping toward the researcher
  • Product protection: HEPA-filtered downflow air creates a clean work zone that prevents airborne contamination of samples
  • Environmental protection: Exhaust air passes through HEPA filters before being released, preventing biological agents from entering the building or outside environment

BSC Class I

Class I BSCs provide personnel and environmental protection only — they do NOT protect the work product.

  • Airflow: Room air draws inward through the front opening, across the work surface, and out through a HEPA exhaust filter
  • Protection: Personnel ✅ | Product ❌ | Environment ✅
  • Applications: Low-risk work where product protection isn’t needed, such as handling diagnostic specimens or mixing hazardous drugs
  • BSL rating: BSL-1, BSL-2

Class I cabinets are relatively rare in modern labs because Class II cabinets provide all the same protection PLUS product protection.

BSC Class II

Class II BSCs are by far the most common type, providing all three types of protection. They use a combination of inward airflow and HEPA-filtered vertical (downflow) air to protect the researcher, the product, and the environment.

Browse our biological safety cabinet selection →

Class II, Type A1

  • Recirculates 70% of air, exhausts 30% through HEPA
  • Can recirculate back to the room or connect to exhaust ductwork
  • Minimum inflow: 75 fpm
  • Suitable for BSL-1 through BSL-3
  • Not for: Volatile chemicals or radionuclides

Class II, Type A2 (Most Popular)

  • Recirculates 70% of air, exhausts 30%
  • Can be canopy-connected to exhaust ductwork for volatile chemical use
  • Minimum inflow: 100 fpm
  • Suitable for BSL-1 through BSL-3
  • Most versatile: Works for microbiology, cell culture, and minute quantities of volatile chemicals when ducted

Class II, Type B1

  • Exhausts 70% of air through HEPA, recirculates 30%
  • Must be hard-ducted to building exhaust
  • Minimum inflow: 100 fpm
  • Suitable for work with small quantities of volatile chemicals and radionuclides

Class II, Type B2 (Total Exhaust)

  • 100% of air is exhausted — no recirculation
  • Must be hard-ducted to building exhaust
  • Minimum inflow: 100 fpm
  • Required for work with larger quantities of volatile chemicals and radionuclides
  • Highest energy consumption of all Class II types

BSC Class III (Glove Box)

Class III cabinets are gas-tight, sealed enclosures with attached rubber gloves for manipulating materials inside. All air entering and leaving passes through HEPA filters. They provide the highest level of protection and are required for BSL-4 (maximum containment) work.

  • Protection: Maximum — gas-tight barrier between researcher and agents
  • Applications: BSL-4 work, extremely dangerous pathogens (Ebola, Marburg)
  • Cost: Significantly higher than Class II ($25,000–$80,000+)

Quick Selection Guide

Your Application Recommended BSC
Cell culture, microbiology, PCR Class II, Type A2
Diagnostic specimen handling Class II, Type A2
Minute volatile chemical + bio work Class II, Type A2 (ducted)
Small-quantity volatile/radionuclide Class II, Type B1
Larger volatile chemical + bio work Class II, Type B2
BSL-4 maximum containment Class III

BSC vs. Fume Hood: Key Differences

The most common mistake in lab safety is using a fume hood when a BSC is needed (or vice versa):

  • Fume hoods protect the USER from chemical fumes. They do NOT provide product protection or biological containment.
  • BSCs protect the USER, the PRODUCT, and the ENVIRONMENT from biological hazards. They are NOT designed for large-volume chemical use.

Read our detailed comparison: Biological Safety Cabinet vs. Fume Hood

Frequently Asked Questions

How much does a biological safety cabinet cost?

Class II, Type A2 BSCs range from $5,000–$15,000 depending on size and features. Type B1 and B2 cost more ($10,000–$25,000) due to harder ductwork requirements. Installation adds $2,000–$8,000.

How often should BSCs be certified?

Annually, or after any move, repair, or filter change. NSF/ANSI 49 requires field certification by a qualified technician using standardized test protocols.

Can I use a BSC as a fume hood?

No. BSCs are not designed to handle volatile chemical fumes. Using a BSC as a chemical fume hood can damage the HEPA filters and compromise containment. Use a chemistry fume hood for chemical work.

Get Expert BSC Selection Help

Not sure which BSC class and type you need? Our lab safety specialists will evaluate your agents, protocols, and lab ventilation to recommend the right cabinet.

Request a free BSC consultation → or call (801) 999-8277.

Chemistry Fume Hoods: Types, Specifications & Selection Guide

Marketing Manager

A chemistry fume hood is the most critical piece of safety equipment in any chemical laboratory. It protects researchers from toxic fumes, vapors, and particulates by drawing contaminated air away from the breathing zone and exhausting it safely outside the building.

Choosing the wrong fume hood can compromise safety, waste energy, and create compliance headaches. This guide covers every fume hood type, the specifications that matter, and how to match the right hood to your lab’s specific needs.

What Is a Chemistry Fume Hood?

A chemistry fume hood is a ventilated enclosure with a movable sash (window) that provides a physical barrier between the user and hazardous chemicals. An exhaust system continuously draws air through the hood face, captures fumes generated inside the hood, and routes them through ductwork to the building’s exhaust system.

The sash can be raised for loading equipment and lowered during experiments to increase containment and reduce energy consumption.

Types of Chemistry Fume Hoods

Constant Air Volume (CAV) Fume Hoods

CAV hoods maintain a constant exhaust volume regardless of sash position. When the sash is lowered, face velocity increases because the same volume of air passes through a smaller opening. These are the simplest and most affordable hoods but use more energy because the fan runs at full speed continuously.

Variable Air Volume (VAV) Fume Hoods

VAV hoods adjust exhaust volume based on sash position, maintaining a consistent face velocity (typically 100 fpm). When the sash is lowered, the fan slows down, reducing energy consumption by 40–60% compared to CAV hoods. VAV systems require a sash position sensor and a variable-speed fan or bypass damper.

Ductless (Recirculating) Fume Hoods

Ductless hoods filter contaminated air through activated carbon or HEPA filters and return it to the room. They don’t require ductwork, making them easy to install and relocate. However, they’re only suitable for specific chemicals that the filter media can capture. Read our detailed comparison: Ductless vs Ducted Fume Hoods.

Benchtop Fume Hoods

Compact hoods designed to sit on a lab bench or countertop. Ideal for teaching labs, small research spaces, and facilities with limited floor space. Explore our benchtop fume hood options →

Walk-In Fume Hoods

Floor-mounted hoods with sashes that extend to the floor, allowing researchers to work with tall apparatus and walk-in setups. Essential for distillation columns, reactor systems, and other oversized equipment. See our walk-in fume hood options →

Biological Safety Cabinets (BSCs)

While not technically fume hoods, BSCs are often confused with them. BSCs protect the user, the environment, AND the product (work) using HEPA-filtered laminar airflow. They’re required for work with biological agents, cell cultures, and sterile procedures. Learn about our biological safety cabinets →

Key Fume Hood Specifications

Face Velocity

Face velocity is the speed of air entering the hood at the sash opening, measured in feet per minute (fpm). OSHA recommends 80–120 fpm for most chemistry applications, with 100 fpm being the most common standard. Higher velocities waste energy; lower velocities may not provide adequate containment.

Sash Configurations

  • Vertical rising sash: Slides up and down. Most common type.
  • Horizontal sliding sash: Panels slide left and right. Saves energy because only part of the face is open.
  • Combination sash: Vertical with horizontal panels. Maximum flexibility.

Standard Widths

Width Best For
4 ft (48″) Teaching labs, small setups, limited space
5 ft (60″) General chemistry, most common size
6 ft (72″) Large setups, multiple operations
8 ft (96″) Walk-in applications, oversized apparatus

Interior Materials

  • Epoxy-coated steel: Most common, good chemical resistance, cost-effective
  • Polypropylene: Excellent acid resistance, required for perchloric acid work
  • Stainless steel: Heat and chemical resistant, used for high-temperature applications
  • Fiberglass (FRP): Strong corrosion resistance, lightweight

How to Choose the Right Fume Hood

  1. Identify the chemicals: What will you work with? This determines material compatibility, filtration needs, and whether ductless is an option.
  2. Determine the size: Consider your equipment footprint, bench space, and the number of users.
  3. CAV vs. VAV: VAV saves 40–60% on energy but costs more upfront. For labs with many hoods, VAV pays back quickly.
  4. Check your HVAC capacity: Each ducted hood requires 500–1,500 CFM of exhaust. Verify that your building’s air handling system can support additional hoods.
  5. Consider work surfaces: Lab work surface materials like epoxy, phenolic, and stainless steel each offer different chemical resistance.

Fume Hood Energy & Sustainability

Fume hoods are the single largest energy consumers in most laboratories, accounting for 40–60% of a lab building’s total energy use. Key strategies to reduce energy consumption:

  • Close sashes when not actively working (this alone can save 30%+)
  • Upgrade to VAV systems
  • Install occupancy sensors that reduce airflow when the lab is empty
  • Use combination sashes to minimize open face area

Frequently Asked Questions

How much does a chemistry fume hood cost?

Standard chemistry fume hoods cost $3,000–$15,000 for the hood unit alone. Installation including ductwork, plumbing, and electrical typically adds $5,000–$15,000. VAV controls add $2,000–$5,000 per hood. Total installed cost ranges from $8,000 to $30,000+ per hood.

How often should fume hoods be tested?

ANSI Z9.5 recommends annual face velocity testing at minimum. Many facilities test semi-annually or quarterly. Continuous airflow monitors provide real-time verification between scheduled tests.

What’s the difference between a fume hood and a biosafety cabinet?

A fume hood protects the USER from chemical fumes. A biosafety cabinet (BSC) protects the user, the environment, AND the work product from biological contamination. If you work with pathogens or cell cultures, you need a BSC, not a fume hood. Read our detailed comparison: BSC vs Fume Hood.

Can I use a fume hood for perchloric acid?

Only a dedicated perchloric acid fume hood with a stainless steel or polypropylene interior and integrated wash-down system. Perchloric acid vapors are explosive and corrosive and must never be used in a standard fume hood.

Get Expert Fume Hood Sizing Help

Our laboratory design team will help you choose the right fume hood type, size, and specifications for your application. Free consultations and 3D lab layouts included.

Request a free fume hood consultation → or call (801) 999-8277.