Laminar Flow Hood vs Fume Hood
In lab environments, laminar flow hoods and fume hoods create workspaces with enhanced ventilation and filtration. However, they have different uses. It is crucial to understand their differences to formulate the correct experimental conditions and guarantee user safety. This article will help you choose between a laminar flow hood and a fume hood.
When to Use a Laminar Flow Hood
Laminar flow hoods (LFH) draw air from the room into the hood workspace. This air is filtered using high-efficiency particulate air (HEPA) filters. The clean air then circulates within the hood before flowing back into the room.
The clean and particle-free environment generated by a laminar flow hood is perfect for conducting low-contamination experiments. Contamination is pushed out of the hood by the flow of filtered air. A laminar flow hood is available in two configurations: horizontal and vertical. The direction of air flow differs between configurations and varies in the way it manages contamination.
Importantly, laminar flow hoods provide little protection for the user. When exiting the hood, the air flow is directed at the user. If you are working with hazardous materials or a large volume of toxic solvents, a laminar flow hood is not the right choice for you.
The purpose of a laminar flow hood is primarily to protect the sample, not the user. Therefore, they are ideal if you need to reduce sample contamination and you are working with non-hazardous materials.
When to Use a Fume Hood
A fume hood draws air from the inside the hood, to remove contaminants and solvent vapours generated in the workspace. There are two types: ducted and ductless. A ducted hood will extract contaminated air into an exhaust duct, and release it into the atmosphere. Ductless fume hoods filter the contaminated air using carbon and HEPA filters before releasing it back into the room. Ductless fume hoods are simpler to install but offer less protection against toxins. In both cases, the contaminated air removed from the hood workspace is replaced with air from the room.
Regardless of type, a fume hood's primary role is to protect the user. These hoods shield you from solvent vapours by actively removing them from your workspace. However, fume hoods provide little protection against sample contamination. In some cases they can make contamination of dust and other particles more likely, as they actively pull air from the room into the workspace. You should use a fume hood if you are working with hazardous materials. If you are unsure if your material should be handled in a fume hood, check the Safety Data Sheet for the material.
While a fume hood will provide some level of protection, the user is still exposed to the substance. For further protection when using very hazardous materials you should use a completely isolated environment, such as a glove box.
Laminar Flow Hood vs Fume Hood: Making the Choice
The table below compares the key properties of laminar flow hoods and fume hoods.
| Laminar Flow Hood | Fume Hood | |
|---|---|---|
| Purpose | Protect samples from contamination | Protect user from hazardous substances i.e., solvent vapours |
| Air Circulation |
Filters incoming air before it enters the hood Air circulates through the chamber, then back into the room |
Air flows from the room through the main chamber Contaminated air is pulled out of the main chamber either through filters or an exhaust duct |
| Weaknesses | Does not protect user from hazardous materials. LFH should not be used with hazardous materials or toxic solvents. | Does not protect samples from contamination. Will drag dust and impurities from the room into the fume hood. |
| Applications |
Non-hazardous microbiology applications Preparing media plates & mammal/plant cultures Fabricating thin films (with non-hazardous solvents) and thin film devices Electronics inspections |
Some hazardous microbiology applications Working with hazardous materials Heavy solvent processing |
A laminar flow hood is ideal for protecting your samples when conducting sensitive experiments. Whereas a fume hood is suited to applications that involve the handling of hazardous or toxic substances. Understanding the purpose of the equipment and how they are different is critical to selecting the right hood for your needs.
Laminar Flow Hoods
- Vertical/Horizontal Models
- Fully Equipped
- High Purity Air
Available Now! £2,500