natural ventilation pressure

[′nach·rəl ‚vent·əl′ā·shən ‚presh·ər]

(mining engineering)

A pressure difference across the shaft-bottom doors caused by a lack of balance in the two vertical air columns.

References in periodicals archive ?

(2006) investigated the pressure of natural ventilation in the shaft of a road tunnel with results indicating that the natural ventilation pressure induced by the shaft has a significant impact on the efficiency of the ventilation system.

Effects of vertical shaft geometry on natural ventilation in urban road tunnel fires

If I were to write my own network program, the branch input would include: * Junction in and out, * Resistance (friction, shock losses) at standard density, * An average branch air density and specific volume, * A fan number, if a fan is present, * A natural ventilation pressure, if desired, based on the dummy branch technique, * A fixed air flowrate, if desired, and * A constant leakage factor, if desired, to account for compressed air additions (injected at junction in).

With careful input of resistances and natural ventilation pressures based on experience (i.e., knowing or estimating air state points at junctions), an incompressible program can predict air flows accurately enough.

Computers in ventilation: nuts-and-bolts ventilation planning and monitoring for hard-rock mines