As we know, the laminar flow cabinet is a device to keep the material in the cabinet away from all kinds of contamination, or keep the laboratory worker and laboratory environment away from the infectious or other hazardous materials. The air streams usually blow at the same speed and in the same direction. There are two kinds of the laminar flow cabinet, one is horizontal

laminar flow cabinet and the other one is vertical laminar flow cabinet. 

For a horizontal flow hood, the air moves from the back of the unit through HEPA or ULPA filters to the front of the work surface, it is in a horizontal direction. And for a vertical laminar flow cabinet, the air moves from the top of the unit through filters down to the work surface, it is in a vertical direction. But how to choose a laminar flow cabinet? Which direction is better, the vertical one or the horizontal one?

For the vertical laminar flow cabinet, it takes up less space than the horizontal one, and the filter can be fitted on the top of the cabinet which is very easy to install. In addition, the operator will not be blown by the air as the air direction. What is more, the cabinet will be cleaned thoroughly and it cause less cross contamination on the work surface. But this also reduce the working life of the filters, and we cant put the materials or hands on the other ones because of the direction of the air flow.

For the horizontal laminar flow cabinet, if we put our hands and gloves on the cabinet, it will not causes much contaminating because of the direction of the air flow. And the air flow effects little on the working surface. However, the air flows directly towards the operator’s face, and the larger samples may prevent the air flow from cleaning the little samples.