Laminar flow hood is an equipment that is commonly used in laboratories for scientific and medical research purposes. It is also used in some industrial facilities to work with sensitive material like semiconductors and other microelectronics. Its main purpose is to create a contamination free environment that is needed to work with laboratory samples and chemicals, or industrial materials like the ones mentioned above.
As the name suggests, a laminar flow hood produces a smooth laminar stream of air that blows away all particles in a specific area. By doing so, it creates a sterile atmosphere in the area where lab operations can be performed on the samples and specimens. The direction of air flow in these hoods can either be vertical (top to bottom) or horizontal (rear to front). Accordingly, such hoods are called vertical or horizontal laminar flow hoods.
What is a vertical laminar flow hood?
A vertical laminar flow hood is a special type of workbench. It is enclosed from all sides barring the front. At the front, a sash is placed at the top half, leaving an open space at the bottom half. A High Efficiency Particulate Air (HEPA) filter is fitted at the top of the hood. The filter takes in impure air from its surroundings, then processes it by obstructing all particles present in the air. Only clean air flows out of the filter, which is projected downwards on the workbench.
As the air moves from the top to bottom, it blows away all the contaminants present in the workspace. These contaminants are swept to the bottom of the workbench then out from the opening at the front. Some particles at the rear end of the bottom of the workbench may not flow outside. So there’s a small opening at the bottom rear end, which leads those trapped particles to the back of the hood all the way up to the filter. This overall mechanism ensures that the entire workspace has a sterile, uncontaminated environment.
Advantages of Vertical Laminar Flow Hoods
Below, some benefits of a vertical laminar flow hood are listed:
– These hoods are taller in height, but they don’t have much depth. So they can be installed even in labs with less floor space.
– Laminar flow hoods are designed to protect the specimen, not the operator. Yet, the positioning of sash at the top half of a vertical laminar flow hoods protect the operator’s face from direct contact with the contaminated air.
– Vertical flow of air does not create much turbulence when it hits objects in the workspace. So large equipments can also be worked with inside vertical laminar flow hoods.
Things to consider when using Vertical Laminar Flow Hoods
– Toxic specimen and chemicals should not be used in these hoods as the operator is not protected.
– The HEPA filter should be inspected and maintained from time to time for efficient performance.
– The workspace should not be loaded with many items, and only the minimum required equipment and samples should remain inside. This is to ensure that the flow of air is not disturbed throughout the operation.