HORIZONTAL AND VERTICAL LAMINAR FLOW

What is laminar flow ?

Numerous germs are constantly circulating in the atmosphere, and more specifically in work spaces. Most people think that manufacturing products or handling biological or chemical samples is an easy task. But this is not the case, as they must not – under any circumstances – be exposed to the bacteria present in the air.

So if you want to work in an ultra-clean environment to protect your preparations, your staff and the environment, several solutions are available; but the most efficient is no doubt the use of equipment with laminar flow technology.

Schéma de filtration HEPA

What is a HEPA filter?

HEPA refers to the air filtration technology known as High Efficiency Particulate Air. HEPA filters are the most effective method of filtering dirt, pollen, bacteria and any other air particle larger than 0.3 µm out of the air

There are different classes of HEPA filter, offering different levels of performance:

  • H10: this filter blocks at least 85% of particles measuring 0.3 µm
  • H11: the percentage increases to 95%
  • H12: the filter blocks 99.5%
  • H13: at least 99.95% of micro-particles are captured
  • H14: almost all particles are absorbed, with an efficiency rate of 99.995%

The efficiency rate of HEPA H14 filters is between 99.995% and 99.9994% of particles greater than or equal to 0.3 µm (according to EN 1822), creating a class-3 ISO work area.

These filters have become more efficient over the years and meet the growing demand for improved air quality, in particular for technological industries such as aerospace, the pharmaceutical industry, the electronics sector, hospitals and research labs.

What is the cost of a laminar flow hood?

The average cost of a laminar flow laboratory hood is between €3,000 and €10,000. The price varies according to the type of protection (protection of the product or of the handler), the size of the equipment and the options chosen.

When you purchase a laminar flow hood, Erlab offers you the possibility of obtaining a maintenance contract or inspection to check the general condition of the equipment and to ensure it is working properly. It should be noted that absolute filters are very efficient, guaranteeing sterility of the work space and biological protection of users. We recommend replacing the filters every 4 to 5 years, and pre-filters every year, to keep the device in the best possible condition and ensure that it provides the required level of protection. The price for filter supply and replacement is between €150 and €1,500.

Laboratoire - Hotte à flux laminaire

What type of flow to choose for a laboratory hood?

Currently, there are two main types of laminar flow: horizontal flow and vertical flow.

Horizontal unidirectional airflow: Cabinets equipped with horizontal laminar flow allow, for example, the evacuation of particles without turbulence. Air enters the cabinet through a horizontal filtration system and exits through a perforated grille. The airflow thus prevents the accumulation of contaminants generated inside the so-called “clean” area by quickly carrying them towards the return surface.

Vertical unidirectional airflow: Vertical flow allows you to achieve the desired air quality over the surface of your cabinet. In other words, this type of airflow is effective across the entire volume, including its width, height, and depth. However, note that with this model, you won’t be protected from various turbulences. In this case, air is blown from a vertical filtration system and is returned through a vertical plenum equipped with perforated plates. The horizontal flow system is a very convenient system offering the best efficiency/cost ratio.

In summary, you should make your choice based on the positioning and characteristics of your samples. For example, handling a low-thickness product requires a horizontal airflow cabinet. Otherwise, it is better to opt for the other type of cabinet to maximize the evacuation of particles from the point of use.

Erlab Laminar Flow hoods