What is Laminar Hood/Laminar Air Flow?

May 17th, 2014 by Acmas Leave a reply »

Laminar Hood sometimes also known as Laminar Air Flow is an enclosed bench designed to prevent contaminations like biological particles (SPM) or any particle sensitive device. This closed cabinet is usually made up of stainless steel without any gap or joints where spores might collect.

Air is drawn through a High Efficiency Particulate Air (HEPA) filter and blown in a very smooth flow or streamline flow (when a fluid flows in a parallel layer with no disruption between the layers)

Laminar Hoods are equipped with a shortwave ultraviolet germicidal lamp to sterilize the shell or cabinet or the surface of the Hood. The Hoods should be turned on about 10-20monutes before being used to kill the germs. It is important to switch off this light during use as it may cause mutations and may give any exposed skin sunburn and may cause cataracts too. It is required to wipe down the cabinet surface with ethanol before and after use and it’s also required to keep the hood free of clutter as possible because this will interfere with the laminar flow air pattern.

Components of the Laminar Hood are

  • A Blower
  • High Efficiency performance Air filter
  • A Plenum Chamber (Pressurized housing containing air at positive pressure)

Why you need Laminar Hood?

  • It provides clean air to the working area.
  • It provides a constant flow of air out of the work area to prevent room air from entering.
  • The air that flows out from the Hood, removes contaminants introduced into the work area by personnel.

The most important  part of a laminar flow hood  is a High Efficiency Particulate Air filter (HEPA). Room air is taken into the unit and passed through a pre-filter to remove gross contaminants (lint, dust etc). The air is then compressed and channeled up behind and through the HEPA filter in a laminar flow fashion. The HEPA filter removes nearly all of the bacteria from the air.

What Safety Precautions should be taken for the Laminar Hood?

  • Large objects should never be placed near the back of the hood. These objects contaminate everything downstream and disrupt the laminar flow pattern of air too, which normally suspends the contaminants and removes them from the area.
  • Waste and other items should never enter the hood. All calculations should be done before entering the hood. And clutter should be less.
  • Hands should be cleaned by ethanol.Do not touch your hair, face or clothing while working.
  • Excess dust should be removed from items before introducing them into the hood.

Comments are closed.