Laminar Flow Hood
Laminar flow hoods are designed to supplement cleanrooms; which can be costly to build.
Using a laminar airflow hood can be an low cost solution for companies requiring a sterile and contamination-free or ISO class 5 working environment. A laminar flow hood is used in laboratories, research facilities, and other controlled environments to provide a sterile and particle-free workspace. It is designed to protect sensitive materials and samples from contamination by creating a unidirectional, filtered airflow.
The primary function of a laminar flow hood is to maintain a laminar flow of air, which means the air moves in parallel layers with a constant velocity and in a single direction. This airflow is usually directed downward, from the top of the hood to the work surface, and then out through vents at the base or sides of the hood.
It is important to note that laminar flow hoods are only recommended for work with non-hazardous materials. They do not provide protection for your personnel. If you need the protection of personnel and samples, you need a biological safety cabinet.
There are two main types of laminar flow hoods:
- Horizontal Laminar Flow Hood: In this type, the filtered air flows horizontally towards the user and the workspace. It is commonly used for applications where protection of the product or sample is the primary concern.
- Vertical Laminar Flow Hood: In this type, the filtered air flows vertically downwards towards the work surface. This design is often used in applications where operator protection is essential, as the airflow prevents contaminants from being released into the surrounding environment.
Laminar Flow hood-Horizontal Airflow Diagram
Laminar Flow hood-Vertical Airflow Diagram
1. Horizontal Laminar Flow Hood
These hoods are typically wider especially when the filter is in the back of work zone, so they require more clearance and more floor space compared to a vertical flow hood.
They are usually preferred for plant tissue culture, electronics inspection and assembly, food industry, Forensic analysis and pharmacy drug preparation. They will not have a front sash so the air stream is going toward the operator.
Horizontal Laminar Flow Single Filter
Horizontal Laminar Flow Double Filters
2. Vertical Laminar Flow Hood
Vertical laminar flow hoods are often selected because they work like a laminar flow clean room but on a smaller scale. These filters are typically positioned in the ceiling directing the clean air downward, purging particles out of the work zone and through a front-access opening.
They feature front sash for personnel protection and act as a physical barrier when working with chemicals. Vertical flow hoods are preferred in microbiology , tissue culture, data recovery, Pharmaceutical Compounding, medical laboratories, Obtics, Electronic assembly, etc.
Benchtop laminar Flow Hood
Laminar Flow Booth
Portable Laminar Flow Hood
Laminar Flow Isolator
Laminar Flow Hoods Performance
Regarding the hood cleanliness performance, most popular laminar flow hoods are in two classes: ISO 4 (Class 10) and ISO 5 (class 100). Classifications are based on particle counts taken at a location within the clean zone of a workstation.
e.g. in ISO 5 (Class 100) laminar flow hoods particle count should not exceed a total of 100 particles per cubic foot of a size 0.5 micron and larger.
Laminar flow hoods are equipped with high-efficiency particulate air (HEPA) or ultra-low penetration air (ULPA) filters. These filters can remove airborne particles, including dust, microorganisms, and other contaminants, down to very small sizes, ensuring a sterile and particle-free environment within the hood.
Laminar Flow Hoods Features
- HEPA (High-Efficiency Particulate Air) Filters: Laminar flow hoods are equipped with HEPA filters, which are highly efficient at removing airborne particles, dust, and microorganisms from the air. These filters ensure that the air inside the hood is clean and free from contaminants.
- Unidirectional Airflow: The laminar flow hood provides a controlled, constant, and unidirectional flow of filtered air that moves from the top (or back) of the hood and exits through the front (or bottom). This minimizes turbulence and prevents contaminants from entering the work area.
- Sterile Workspace: The laminar flow of clean air creates a sterile working environment within the hood, which is crucial for applications that require aseptic techniques or work with sensitive samples.
- Vertical or Horizontal Flow: Laminar flow hoods come in two main configurations: vertical flow and horizontal flow. Vertical flow hoods direct the filtered air downward towards the work surface, while horizontal flow hoods direct the air horizontally over the work area.
- Work Surface: Laminar flow hoods have a smooth, flat work surface made of stainless steel or other easy-to-clean materials. The work surface is designed to be free of crevices and seams that could trap contaminants.
- UV Light: Some laminar flow hoods may have built-in ultraviolet (UV) lights. UV light helps to sterilize the interior of the hood when it is not in use, further reducing the risk of contamination.
- Control Panel: The hood typically has a control panel that allows the user to adjust the fan speed, turn on/off the UV light (if present), and monitor the airflow and filter status.
- Airflow Alarm: To maintain the integrity of the sterile environment, laminar flow hoods may be equipped with an airflow alarm that alerts the user if the airflow drops below the required level, indicating a potential issue with the filter or fan.
- Sash or Front Opening: In vertical flow hoods, there is a front sash that can be raised and lowered to access the work area. In horizontal flow hoods, the front opening provides access to the workspace.
- Casters or Leveling Feet: Many laminar flow hoods are designed to be easily portable and may come with casters for mobility. Some models have leveling feet to ensure stability during use.