Kristiono's First Law of Thermodynamics

Δω = (1/ hfg) [(mda/mcv) ((0.622 hfg фPs)/(Patm – фPs)+ CpTrm) - CP ΔT]

Where,
ф desired level of relative humidity
mda mass of dry air supplied
mcv mass of air in the control volume
hfg specific molar enthalpy of air
ω3 absolute humidity of outlet air (= ambient air)
ω1 absolute humidity of inlet air
T3 outlet temperature
T1 inlet temperature
Cp specific constant pressure heat coefficient of dry air
Trm room temperature
Patm atmospheric pressure
Ps partial pressure of saturated vapour

-no wonder I'm stressed-