QUESTION

a) Describe briefly the two classes of glare that employees may encounter in their work environment due to poor quality of lighting

b) The Fan Laws define the relation of volume flow, pressure and power against the fan speed. How does the volume flow, pressure and power varies with the fan speed ratio if the speed is varied whilst diameter and density remain constant

c) Name the test equipment that a Ventilation Engineer has to use in order to assess the efficiency of a Local Exhaust Ventilation system. Your answer should mention which instruments that measure the corresponding physical parameters.

d) The threshold of hearing corresponds to a reference intensity of 10^-12Wm^-2. If the sound intensity is 1mW/m², find the sound pressure level in decibels

e) Briefly elaborate on three common indices of thermal stress used in assessing employee's comfort in a hot working environment