The starting point for the design of all LEV systems is with capture, the other elements of the system cannot be designed until the air volume necessary for capure has been determined. It is important for employers and operators to be involved at this stage, the designer needs to know every aspect of the process being undertaken and the sources of release throughout.
The proximity of a capture hood to a source of release determines the air volume required to control the process. The cost and power consumption of the system will increase as the air volume necessesary for control increases. A balance must be found where control can be achieved without hindering the process.