Horizontal laminar flow hoods direct air, well, horizontally. Air is pushed through a HEPA or ULPA filter positioned on the back wall and moves forward across the work surface until it exits the enclosure.

By sweeping the air across the work surface and towards the operator, horizontal laminar flow hoods provide the highest protection from contaminating particles. No turbulence is caused by vertical air striking a perpendicular surface or the hands of the operator since they’re always further downstream than the materials they are working on.

However, the hood’s size, the filter’s positioning, and the airflow’s direction can also result in some negative consequences. Below, we’ll detail the complete list of pros and cons for these types of hoods: