Laminar flow hoods are a crucial device for filtering the airflow continuously across laboratory spaces to eliminate particulate contamination of the samples. The term ‘laminar’ itself means layered flow that indicates that the flow of air is calm along constant streamlines; flowing within the enclosed bench at the same speed and direction. Industries varying from medical research to electronics may sometimes demand a clean and sterile environment to conduct its experiments and research. The laminar flow hoods are a one-stop solution for providing a contaminant-free atmosphere to its workers.

The two variants of laminar flow hood

There are two types of flow hood configurations that are classified according to the direction of airflow - Horizontal and vertical. Either of them is designed to remove maximum particulate build-up on stagnant air zones to provide a clean, sterile workspace. With turbulent flows, there is always a greater risk of cross air contamination whereas a laminar flow allows all the air to sweep through the unit space uniformly and is then passed through HEPA or ULPA filters for capturing dust and unwanted particles.

What are the major dissimilarities between them?

Horizontal laminar flow hood: This system has been designed to facilitate the airflow horizontally starting from behind the HEPA filter to the front direction providing 99.99% particle-free results. These filters are located on the reader end and air flows along the work surface without hindrance. But, this configuration has considerable setback as the user stands downstream of the device getting exposed to the air received on the front end carrying any unfiltered contaminant. They are used with low hazard level filtration materials. This type of flow hood requires greater bench depth and floor space to fit in the rear-mounted filters.

Horizontal laminar flow hoods are ideal for you if your task demands maximum particulate protection for the samples. While both fume hoods require less turmoil on the work surface, horizontal ones render slightly fewer disturbances giving better filtration results. Smaller pieces of equipment and utensils are generally kept to avoid any kind of flow hindrance; larger ones would block the movement of air causing turbulence.

Vertical laminar flow hood: These flow hoods are designed for facilitating the vertical flow of air from the top area passing through HEPA filters mounted on ceilings. The air moves downwards reinforcing the gravitational pull on the particulates sweeping them out through holes or front access areas. This operation is based on the laws of Newtonian motion, where air moves quickly causing the dust to separate and settle on the work floor. This mechanism provides enhanced protection and does not expose you directly to leftover contaminants in the air. They are used with hazard level 2&3 materials but level 4 requires sealed bio-safe cabinets. This system is more popular than the horizontal one owing to limited space requirements and lesser bench depth.

The vertical laminar flow hoods are ideal for working with larger equipment and when soldering fumes and fine powder need to be used for taller workspace.

Why should you choose a particular product?

To make the right choice of flow hoods for your clean bench it is necessary to understand the benefits it offers as well as its drawbacks. A good comparison would enable you to conclude what is preferable for your work.

Vertical laminar flow hood:

PROS

  • lower turbulent effects of airflow while hitting larger samples or processing equipment
  • The filter is placed on top which makes it easier to access.
  • Greater protection of the operator because the sash creates a barrier and prevents the air to get discharged directly at the worker's face.
  • Lower cross-contamination
  • The flow hood is shallow and requires minimum floor space.

CONS

  • Due to the taller workspace, filter changing and servicing would require a step ladder.
  • Needs Overhead clearance for uninterrupted particulate removal.
  • Cannot place any other item on top of other items that would obstruct the airflow.
  • The flow of air is perpendicular to the work surface, while hitting it, may trigger turbulent effects

Author Bio

Cleatech LLC, the leading company manufactures laboratory and cleanroom equipment. Buy the top-quality Laminar Flow Hood and other laboratory equipment such as Flow Wall Modules at Cleatech.com.