Here we introduce a formula as follows:

Hs = 1.08×Q(cfm)×ΔT(Temperature difference in ℉)

∴ Q = Hs/(1.08×ΔT)

Eg.:

Rack inlet temp = 18℃(64.4℉)

Rack outlet temp = 24℃(75.2℉)

Under floor static pressure = 0.,025-0.05 in.wg (in.H2O)

*At 3kw/rack (1W = 3.412Btu/h)

Q = 10236/[1.08×(75.2-64.4)] = 878 cfm

*At 5kw/rack

Q = 17060/[1.08×(75.2-64.4)] = 1463 cfm