Nice work Sandman
The term Laminar Flow as it applies to hoods or clean air equipment can typically means air flowing in one direction (unidirectional) with very low turbulence. In a horizontal "Clean Bench" air flows straight out of the hood towards the operator.
Laminar Flow Hoods provide clean air to the working area. They provide a constant flow of air out of the work area to prevent room air from entering. The air flowing out from the hood suspends and removes contaminants introduced into the work area by personnel.
The most important part of a laminar flow hood is a high efficiency bacteria-retentive filter. 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 (High Efficiency Particulate Air filter) in a laminar flow fashion--that is the purified air flows out over the entire work surface in parallel lines at a uniform velocity. The HEPA filter removes nearly all of the bacteria from the air.