Laminar flow creates an aseptic, non-turbulent work environment for a variety of applications. This technique for airflow particulate cleanliness has been in wide use to protect animal and human beings, processes, and products since the 1970s. In 2000 the International Standards Organization published performance standards. The term originates from the word laminae, the plural of lamina, referencing the layers of air that flow over one another to guarantee clean layers of air.
It is easy to illustrate both the necessity and the principle of air particulate cleansing if you look at a window when it’s opened. Sunlight falls on tiny dust motes traveling through the room’s air. Now suppose that someone with a viral infection has just sneezed into the room, Laminar Air Flow and the spray that he exhales contains hundreds of thousands of viruses. What if each one of them attaches itself to a dust particle?
Laminar flow hoods remedy that dilemma, and they have many additional applications. But first consider how they work. There are two basic designs: vertical or horizontal hoods.
Vertical hoods channel the room’s air through an intake. A blower directs it toward a HEPA (high efficiency particulate air filter). Some of the air is eliminated via an exhaust vent and leaves the area entirely. Once the air is filtered through the HEPA, it flows back into the room. The air flows constantly through the room, in layers. Suppose we are in the hospital room of a patient, and a hospital technician enters the area. The laminar flow hood will draw contaminants off the technician and immediately cycle them through the HEPA.
Horizontal hoods are typically designed as work benches. Below the work surface you will find a pre-filter that draws the room’s air up to the HEPA. From the HEPA the air is cycled smoothly over the work surface.
General applications for laminar flow include medical, scientific, pharmacologic, robotic, industrial, and aerodynamic applications, such as:
- Directing airflow in the room of a patient who must not come in contact with contaminants. An example is the burn patient, with large exposed areas of flesh.
- Controlling airflow in the room of a patient who is extremely contagious, so that the contaminants he emits will not enter the environment of unprotected individuals.
- Biological laboratories in which contagious bacterial or viral germs must remain contained.
- Pharmacological facilities in which environmental control permits successful compounding of sterile medications or solutions-think chemotherapy-or in intravenous solution preparation.
- Biological testing laboratories, when the integrity of animal or plant specimens must be guaranteed.
- Robotic equipment, whether utilized in the preparation of medical admixtures, high throughput testing, or industrial small part assembly.
- Scientific applications, in which the quality of air emissions must be guaranteed during quality control processes for small computer system interfaces or other instances of equipment sensitivity.
- Industrial uses, including the use of laminar flow to eliminate sound and air vibrations disruptive to sensitive equipment.
- Electronic testing, inspection, and manufacturing.
- Food industry, for aseptic food preparation.