11 Types Of Fume Hoods In Your Laboratory

Quick Summary

Eleven hood types cover most laboratory work, from general chemistry through perchloric acid, radioisotope, and walk-in designs. The chemistry decides the hood: perchloric acid work needs wash-down capability, radioisotope work needs particular liners, and a general chemistry hood substitutes for neither.

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Not all fume hoods serve the same purpose, and understanding the different types of fume hoods available helps laboratories choose equipment suited to their specific work. Each type is engineered to address particular hazards, whether that involves general chemical handling, corrosive acids, or specialized materials requiring extra containment, and SEFA publishes recommended practices covering how these hoods are built and tested.

1. Conventional Fume Hoods

Conventional fume hoods, sometimes called constant air volume hoods, maintain a fixed volume of exhaust air regardless of sash position. This straightforward design makes them a reliable, cost effective choice for general laboratory use, though the airflow does not adjust automatically as the sash opens and closes, which can affect energy efficiency compared to more advanced options.

2. Bypass Fume Hoods

Bypass fume hoods address one of the main drawbacks of conventional hoods by incorporating a bypass air opening above the sash. As the sash closes, this opening allows additional air to enter, helping maintain a more consistent face velocity across different sash positions. This design improves safety consistency without requiring the more complex mechanisms found in variable air volume systems.

3. Variable Air Volume Fume Hoods

Variable air volume, or VAV, fume hoods adjust exhaust airflow automatically based on sash position, reducing energy consumption when the hood is not in active use with the sash fully open. These hoods are increasingly popular in laboratories focused on energy efficiency, since they can significantly reduce the amount of conditioned air being exhausted compared to constant volume systems.

4. Auxiliary Air Fume Hoods

Auxiliary air fume hoods supplement the room’s air supply with a dedicated stream of outside air directed into the hood, reducing the demand on the building’s general HVAC system. While this design was more common in older laboratory buildings, it can create challenges with humidity and temperature control if the auxiliary air is not properly conditioned before entering the hood.

5. Distillation Fume Hoods

Distillation fume hoods are designed with additional vertical space to accommodate tall glassware and equipment used in distillation processes. These hoods often include specialized service fittings for water, gas, and vacuum lines, supporting the specific setup requirements of distillation work without sacrificing safety or accessibility.

6. Radioisotope Fume Hoods

Radioisotope fume hoods are constructed with seamless, easily decontaminated interior surfaces and specialized ventilation to safely handle radioactive materials. These hoods often include additional shielding and are designed to minimize crevices where radioactive contamination could accumulate, supporting both worker safety and regulatory compliance for laboratories working with isotopes.

7. Perchloric Acid Fume Hoods

Perchloric acid presents unique hazards because it can form explosive residues within standard ductwork over time. Perchloric acid fume hoods are constructed with special coatings and washdown systems that allow the interior and ductwork to be regularly rinsed with water, preventing dangerous perchlorate crystal buildup that could otherwise pose a serious explosion risk.

8. Walk-In Fume Hoods

Walk-in fume hoods extend to floor level, allowing large equipment or bulky apparatus to be wheeled directly into the hood rather than lifted onto a standard countertop. This design supports laboratories working with oversized equipment while maintaining the same containment principles found in standard bench top hoods.

9. Ductless Fume Hoods

Ductless, or filtered, fume hoods recirculate filtered air back into the laboratory rather than exhausting it outside the building. These hoods rely on activated carbon or HEPA filtration to capture contaminants and are often chosen for laboratories where installing exhaust ductwork is impractical, though they require diligent filter monitoring and are not suitable for all chemical applications.

10. High Performance Low Flow Fume Hoods

High performance, low flow fume hoods are engineered to provide effective containment at reduced face velocities, typically between seventy and ninety feet per minute compared to the standard range of most conventional hoods.

This design reduces energy consumption significantly while maintaining safety, making these hoods an increasingly popular choice for laboratories prioritizing sustainability alongside worker protection.

11. Biological Safety Cabinets

While technically distinct from chemical fume hoods, biological safety cabinets are often grouped alongside laboratory fume hoods due to their similar containment function.

These cabinets use HEPA filtration to protect against biological hazards rather than chemical vapors, and different classes of biological safety cabinets offer varying levels of protection depending on the specific biosafety requirements of the work being performed.

Maintaining Whichever Fume Hood You Choose

Regardless of which type ultimately fits your laboratory, ongoing maintenance plays a central role in ensuring continued protection for your staff.

Regular certification testing, prompt attention to any performance issues, and training every new user on proper operation all help extend the useful life of your equipment while keeping your laboratory in compliance with relevant safety expectations.

Establishing a clear maintenance schedule from the moment a new fume hood is installed makes this ongoing responsibility far easier to manage over time.

How LOC Scientific Supports Your Fume Hood Selection

As a company that designs, sells, and installs laboratory furniture, fume hoods, and accessories, LOC Scientific brings hands-on experience to every fume hood recommendation we make. We understand that choosing the right fume hood involves balancing safety requirements, budget, and the specific demands of your research or testing processes.

Our team works with you to identify the type of fume hood best suited to your laboratory, then supports you through installation and beyond with responsive customer service you can count on. Talk to the team at LOC Scientific today for expert guidance tailored to your specific needs.

Frequently Asked Questions