Exhaust Snorkels for Labs: Source Capture, Selection, and Setup
When working in a lab, you often deal with fumes, dust, or vapors. An exhaust snorkel is a critical tool for safety. It is a flexible, articulated arm designed to capture airborne contaminants at the source.
This method is called localized exhaust ventilation (LEV). The goal is to stop contaminants from reaching your breathing zone or spreading into the lab. It is not a full fume hood. Instead, it is a targeted solution for smaller tasks on an open benchtop. It offers great flexibility and better energy efficiency.
What Are Exhaust Snorkels?
An exhaust snorkel is based on the principle of source capture. This approach is more effective and energy efficient than general room ventilation. Diluting contaminants after they spread is less effective.
By placing the snorkel’s hood near the emission source, you create a focused airstream. This stream immediately pulls harmful substances away from technicians. Think of it like using a vacuum nozzle directly on a spill instead of a fan from across the room. The targeted method is better.
How Snorkels Differ from Fume Hoods
People often ask about the difference between a snorkel and a fume hood. Both are important ventilation tools, but they have different jobs. A fume hood is a large, enclosed box. It provides a physical barrier for experiments with large volumes of hazardous materials.
An exhaust snorkel offers flexibility. It is the perfect tool for tasks on an open bench that produce smaller, localized fumes or particles. Because it only pulls a small amount of air from the room, it is a more energy conscious choice for the right applications. A detailed localized exhaust snorkel overview can help you see how these systems fit into a total lab safety plan.
How to Choose the Right Exhaust Snorkel
Selecting the right exhaust snorkel requires a careful process. You must match the equipment to the specific hazards and your team’s workflow. Following a step-by-step approach ensures you choose a snorkel that meets safety and practical needs.
1. Define the Hazard Profile
First, identify what you need to capture. The type of contaminant is the biggest factor in your choice of material and design.
- Chemicals and Solvents: If you work with acids, bases, or volatile organic compounds (VOCs), you need a chemical resistant snorkel. These are typically made from polypropylene to prevent corrosion.
- Particulates and Dust: For fine powders or dust, a standard snorkel is usually sufficient. The main concern is having enough airflow to capture particles effectively.
- Static Sensitivity: In labs with sensitive electronics, static discharge can damage components. An ESD safe snorkel uses conductive materials to ground static electricity safely.
2. Assess Capture Point Geometry
Next, look at your workstation’s physical layout. The snorkel must reach the fume source without blocking the user or other equipment.
Measure the distance from the mounting point to all possible work spots. Snorkel arms have a specific maximum reach, so ensure your choice can cover the entire work zone. More joints in the arm provide more flexibility for precise positioning.
3. Calculate Required Airflow (CFM)
Airflow, measured in cubic feet per minute (CFM), determines performance. This number relates to capture velocity. Capture velocity is the air speed needed to pull contaminants into the ductwork.
The required CFM depends on the contaminant and the process. Heavier particles or fumes released with force require higher capture velocity. As a rule, place the capture hood as close as possible to the source, usually within one duct diameter. A ventilation engineer can help determine the exact CFM your application needs.
4. Select the Mounting Configuration
How the snorkel attaches to your lab affects usability and stability.
- Ceiling Mount: Ideal for labs with high ceilings or when bench space is limited. This option offers the greatest range of motion.
- Wall Mount: Saves space and provides a stable base for benches against a wall.
- Bench Mount: The most stable option for a fixed workstation, but it takes up some bench space.
Your choice depends on your lab’s construction, exhaust duct locations, and workflow flexibility.
5. Choose Necessary Accessories
Finally, select accessories to optimize the snorkel for your tasks. The capture hood is the most critical accessory.
- Dome or Bell Hoods: Best for capturing fumes that rise, like from heated processes.
- Flat Screen Hoods: Use these to capture fumes across a wider, flatter area.
- Slotted Hoods: Designed to pull fumes horizontally.
Also consider add ons like airflow dampers. These let users adjust the CFM at their workstation. This is useful when multiple snorkels are running at once.
Comparing Exhaust Snorkel Materials and Features
The materials and design of an exhaust snorkel determine its safety, performance, and lifespan. A standard arm perfect for soldering fumes could fail quickly if exposed to acids. Understanding the core differences between the main snorkel types is essential.
Standard (Original) Snorkel Arms
The standard lab snorkel arm is a versatile choice for general purpose fume and dust capture. These arms have anodized aluminum tubes and polypropylene joints. They offer a balance of light weight and strength.
This design is a good match for non corrosive contaminants, such as:
- Light dust from weighing powders
- Soldering fumes
- Mild solvent vapors
- General odors
Chemical Resistant Snorkels
When processes involve aggressive chemicals, a chemical resistant snorkel for corrosives is necessary. These snorkels are made to withstand chemical attack. The tubes and joints are typically 100% polypropylene. This plastic is known for its resistance to acids, bases, and many solvents.
These are the clear choice for applications like:
- Acid digestions
- Work with volatile organic compounds (VOCs)
- Sample prep with strong solvents
ESD Safe Snorkels
In electronics manufacturing and repair, static electricity can destroy sensitive components. An ESD safe extraction arm for electronics work eliminates this threat.
These snorkels are built with conductive materials and are connected to a ground point. This allows any static charge to dissipate safely. This feature protects microchips and circuit boards from electrostatic discharge (ESD) damage.
Exhaust Snorkel Model Comparison
This table breaks down the key differences between the three main types of exhaust snorkels. Use it as a quick reference to compare specifications.
| Feature | Original/Standard Snorkel | Chemical-Resistant Snorkel | ESD-Safe Snorkel |
|---|---|---|---|
| Typical CFM Range | 35 – 250 CFM, depending on diameter | 35 – 250 CFM, depending on diameter | 35 – 250 CFM, depending on diameter |
| Arm Materials | Anodized aluminum tubes, polypropylene joints | All polypropylene tubes and joints | Aluminum tubes with a conductive powder coat, polypropylene joints |
| Compatible Diameters | 2-inch, 3-inch, 4-inch | 2-inch, 3-inch, 4-inch | 2-inch, 3-inch, 4-inch |
| Best Applications | Soldering, light dust, non-corrosive fumes, general lab use | Acid/solvent vapors, corrosive environments, chemical analysis | Electronics assembly, R&D labs, static-sensitive component work |
| Pros | Cost-effective, lightweight, versatile | Superior resistance to harsh chemicals, durable | Prevents electrostatic discharge, protects sensitive electronics |
| Considerations | Not suitable for corrosive materials. | Higher initial cost, may not be necessary for all tasks | Required only for static-sensitive applications. |
You can explore a full range of exhaust snorkels and accessories here.
Snorkel Use Cases and Decision Scenarios
Theory and specifications are one thing. Seeing how snorkels perform in a working lab is another. These arms solve specific safety problems at the bench. A few common scenarios show why choosing the right snorkel is so important.
Scenario 1: Electronics Soldering Station
- Challenge: Soldering creates harmful flux fumes and poses a risk of electrostatic discharge (ESD) to sensitive components.
- Solution: An ESD safe snorkel. It captures fumes at the source while its conductive construction grounds static electricity.
- Placement: Position the hood 4 to 6 inches above the solder joint. A stable bench mount is ideal for repetitive tasks.
Scenario 2: Small Volume Acid Titration
- Challenge: Working with small amounts of acid on an open bench creates corrosive vapors that are an inhalation hazard.
- Solution: A chemical resistant snorkel made from polypropylene. It will not degrade from exposure to acid fumes.
- Placement: Place the hood near the beaker to create a zone of negative pressure that pulls vapors away from the user.
Scenario 3: Pharmaceutical Powder Weighing
- Challenge: Weighing fine powders can create airborne dust that should not be inhaled. Air currents must be minimized to avoid disturbing sensitive scales.
- Solution: A standard snorkel with a wide, bell-shaped hood.
- Placement: Position the hood just above and behind the weighing station. This captures rising dust without creating turbulence near the balance.
Scenario 4: Art Restoration and Solvent Use
- Challenge: Art restorers often use small amounts of solvents to clean artifacts. These tasks require precise control and fume capture in a non-traditional lab setting.
- Solution: A standard snorkel with good articulation and a small, targeted hood.
- Placement: A ceiling or wall mounted arm offers the most flexibility to position the hood near the artifact without touching it.
Scenario 5: University Teaching Lab
- Challenge: A teaching lab has multiple workstations where students perform various experiments with mild chemicals or biological samples.
- Solution: Multiple standard snorkels, perhaps one for every two students. They offer a cost effective way to provide source capture for general use.
- Placement: A combination of ceiling and wall mounts can cover all stations without cluttering the benches.
Integrating Snorkels with Benches and Casework
Proper installation is a critical final step. A snorkel must be integrated into your lab’s space and ventilation system. This requires planning for ductwork, your building’s exhaust system, and snorkel placement. Good integration results in a clean workspace with effective source capture.
Mounting Options for Lab Benches
The mount type directly impacts reach, stability, and bench space.
- Ceiling Mounts: Best for high ceilings or when bench space is limited. They provide maximum range of motion.
- Wall Mounts: A good middle ground that saves bench space while offering a stable base.
- Benchtop Mounts: Offer the best stability for dedicated workstations but take up a small footprint.
Ductwork and System Connection
The snorkel arm must connect to your building’s main exhaust system. Ducting design is important for proper airflow.
The length of the duct run and the number of bends add static pressure. This is the resistance the exhaust fan must overcome. Too much static pressure can reduce the snorkel’s CFM and capture velocity. An HVAC engineer can help balance the system to ensure each snorkel gets its designed airflow. This ensures proper function for all hoods and enclosures in the facility.
Maintenance and Lifecycle Guidance
An exhaust snorkel is a critical safety device that requires regular maintenance. A simple inspection schedule ensures its performance and extends its life. Consistent upkeep prevents small issues from becoming major safety failures.
Routine Inspections and Cleaning
A visual and physical check should be part of your lab’s safety walkthrough.
- Check Arm Tension: The arm should move smoothly and stay in position. If it drifts, adjust the tension according to the manufacturer’s guide.
- Inspect Seals: Look at the O-rings and seals in the joints for cracks or wear. A degraded seal can cause air leaks and reduce suction.
- Clean the Capture Hood: Keep the hood free of dust and residue. A mild detergent and water usually work. For a chemical resistant model, ensure the cleaning agent is compatible with polypropylene.
Periodic Airflow Verification
At least once a year, you should verify the system’s airflow. This ensures it still meets its original design specifications for capture velocity.
This task is typically done by an EHS professional using a calibrated anemometer. They measure air speed at the hood’s face and calculate the airflow in CFM. Low numbers could indicate a clog, a fan issue, or a leak. Keeping records of these checks is a key part of any lab safety program and is fundamental to overall fume hood safety.
Frequently Asked Questions About Exhaust Snorkels
What is the main difference between an exhaust snorkel and a fume hood?
A fume hood is a large, enclosed cabinet that provides a physical barrier for hazardous work. An exhaust snorkel is a flexible arm for capturing contaminants at the source on an open bench. Snorkels are for smaller, localized tasks and are more energy efficient.
How do I calculate the right CFM for my application?
The correct CFM (Cubic Feet per Minute) provides enough capture velocity to pull contaminants into the snorkel. The required velocity depends on the hazard. An industrial hygienist or ventilation engineer can help you determine the precise CFM needed for safety and compliance.
Can snorkels be used in cleanrooms?
Yes, but they must be made from non-shedding materials like stainless steel or electropolished aluminum. The system must capture contaminants without disrupting the room’s laminar airflow.
What chemicals can a chemical resistant snorkel handle?
A chemical resistant snorkel is typically made from polypropylene. This material resists a wide range of acids, bases, and organic solvents. However, you should always check your specific chemicals against a polypropylene chemical compatibility chart to ensure safety.
What is the maximum reach of a snorkel arm?
Snorkel arms are available with a reach from about 3 feet to over 8 feet. Measure your workspace to ensure the arm can reach all emission sources. It is wise to choose a model with slightly more reach than you think you need for added flexibility.
Do I need a separate exhaust fan for my snorkel system?
Yes, in almost all cases. A snorkel arm is a passive component. It needs an external fan to create the suction required to pull air through the system. The fan must be sized correctly to handle the system’s static pressure and deliver the necessary CFM at the hood.
How should the capture hood be positioned for best results?
The capture hood should be placed as close to the emission source as possible. A good rule of thumb is within one duct diameter of the source. This maximizes capture efficiency and prevents contaminants from escaping into the workspace.
Are there any standards that govern exhaust snorkel performance?
Yes. Organizations like the American Conference of Governmental Industrial Hygienists (ACGIH) provide guidelines for local exhaust ventilation systems in their Industrial Ventilation Manual. These guidelines offer recommendations for capture velocities for different types of contaminants.
Find the Right Snorkel for Your Lab
Choosing the correct exhaust snorkel is a critical step in creating a safe and efficient laboratory. By carefully considering your specific hazards, workspace layout, and workflow, you can select a source capture solution that protects your team and integrates seamlessly into your facility.
Labs USA stocks a wide range of lab furniture, including lab tables, workstations, shelving, and related ventilation components. We can help you find the right equipment for your needs.
- Compare exhaust snorkels and accessories to find the best fit for your application.
- Request a quote or plan your lab layout with our specialists today.