Supply Air Flow Rate
If the maximum ventilation supply air rate is taken from Table 3.6 to be 10.0 air changes per hour, then the mass flow rate can be calculated.
Volume flow rate (m3/h) = Volume of room (m3) x air change rate (ac/h)
Volume of room (m3) = 15 x 10 x 6 = 900 m3
Volume flow rate (m3/h) = 900 (m3) x 10 (ac/h)
Volume flow rate (m3/h) = 9000 m3/h
Volume flow rate (m3/s) = 9000 / 3600 = 2.5 m3/s.
Mass flow rate = Volume flow rate / specific volume
The specific volume at the supply condition may be approximated at this stage from a psychrometric chart. It is 0.834 m3/kg.
Mass flow rate (Supply Air) = 2.5 / 0.834 = 3.0 kg/s.