The Mechanical Impact of Aerodynamic Stall on Tunnel Ventilation Fans

Table 4

Factors impacting on fan capital and through life cost.

Design point pressure	1.500 Pa
Pressure pulse	500 Pa
Design point flow	85 m^3/s
Fan type	Reversible, 300°C for 2 hours
Running hours per year	4.400 (12 hours a day)
Cost of electricity	0.04 £ per kW/Hour
Cost of capital	8%
Period of assessment	10 years