Vertical vs Horizontal: Choosing the Right Laminar Flow Hood
A laminar flow hood (LFH) is an essential tool used in scientific and industrial applications to create a controlled, clean environment. To safeguard sensitive experiments and processes are from contamination filtered air moves in a smooth, unidirectional flow, maintaining a particle-free zone.
Two main types, vertical and horizontal, are available. The difference between them is the direction of air flow through the hood—clean air will either flow horizontally or vertically. Each orientation offers distinct advantages depending on the application. Selecting the right system depends on your specific experimental setup and requirements.
Most systems are designed with a fixed orientation, requiring you to decide on the air flow direction before purchase. However, the Ossila Laminar Flow Hood is interchangeable, allowing you to assemble it in both the vertical and horizontal orientation.
Laminar Flow Hood

The Difference Between Orientations
In horizontal laminar flow hoods, the filters are fixed to the back wall of the unit. Air is pulled from the back of the hood through the filter. The filtered air travels parallel to the work bench across the length of the hood and exits through the front opening. Whereas, in a vertical system, the filtered air is directed vertically through the workspace. At the work bench, the air flow is redirected out of the front panel. In these hoods, the filters are on the top panel of the unit.
When to Choose a Horizontal System
Generally, horizontal systems are best suited to simple benchtop-based experiments, which do not use hazardous materials, where reducing contamination is a priority. Examples include media plate preparation, growing plant or mammal tissue cultures, small electronics inspection, or thin film deposition.
Advantages
- Placing your hands inside a horizontal LFH will not disrupt the laminar flow. The air flow travels parallel to the workbench and flows around your hands.
- Contaminants introduced by hands or gloves are quickly removed from the workspace. In the vertical configuration, contamination on your gloves could be carried onto the samples underneath. This does not happen with horizontal air flow, so there is a low risk of the user contaminating the sample.
- Low air turbulence near the work surface creates ideal clean air conditions for conducting workbench experiments or reactions.
Disadvantages
- Air flow, along with any contaminants, is directed towards the user. Even if working with non-hazardous materials, this can be uncomfortable or hazardous.
- Large or bulky equipment can block the laminar air flow and reduce the hood effectiveness.
- Risk of sample contamination from other items within the hood.
- Harder to access and change filters than a vertical LFH.
When to Choose a Vertical System
If you need to maintain low contamination levels while using large or bulky equipment, a vertical system is the right choice. They are also a good choice if you prefer more user protection. For example, if you are working with powders, the vertical configuration prevents materials from being blown directly at you. Some relevant uses for vertical LHFs include non-hazardous microbiological applications, large electronics inspections, and non-hazardous chemical reactions and procedures.
Advantages
- Large or bulky equipment will not interrupt the downward laminar flow. You can use larger equipment such as a spin coater, sonicator, or UV ozone cleaner with this configuration.
- Air flow is not directed immediately into the room, which offers greater comfort and safety to the user.
- Easier access for HEPA filter maintenance and replacement.
- Reduced risk of cross-contamination from other materials in the workspace. In horizontal LFHs, samples positioned at the front of the hood may be susceptible to contamination from materials at the back of the hood.
- The useable workspace is maximized as the filters are positioned above the work bench.
Disadvantages
- Placing your hands into the workspace can disrupt the air flow, reducing the effectiveness of the hood.
- Air flow in a vertical LFH is more turbulent than in a horizontal LFH, especially at the work surface.
- Downward air flow can disturb smaller samples or open solutions in the workspace, as the air flow is aimed directly at the bench.
- Contaminants on your gloves or airborne particles can be carried onto samples on the work bench. The risk of user contamination is increased with a vertical air flow.
An Interchangeable Option
Our interchangeable laminar flow hood offers versatile configuration options, allowing you to switch between vertical and horizontal orientations to suit your specific experimental needs. The benchtop design means reconfiguration for a range of different applications is easy.
Our system provides the same functionality as two separate units available elsewhere on the market, making it a cost-effective solution that delivers a uniform, clean air flow. With the Ossila Laminar Flow Hood, the focus is always on successful experimental outcomes, not budget constraints.


Laminar Flow Hood

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We tested for air and surface contamination in our laminar flow hood. Our system can maintain a contaminant-free environment for up to 24 hours.
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Two main types, the vertical laminar flow hood and the horizontal laminar flow hood, are available. The difference between the vertical and horizontal configuration is the direction of air flow through the hood.
Read more...