The air in a house is at 25°C and 72 percent relative humidity. Now the air is cooled at constant pressure. The temperature at which the moisture in the air will start condensing is

Question

Quizplus · Accepted Answer

Solved by EES Software. Solutions can be verified by copying-and-pasting the following lines on a blank EES screen. 
T1=25 "C"
RH1=0.72
P_g=PRESSURE(Steam_IAPWS,T=T1,x=0)
RH1=P_v/P_g 
T_dp=TEMPERATURE(Steam_IAPWS,x=0,P=P_v)
"Some Wrong Solutions with Common Mistakes:"
W1_Tdp=T1*RH1 "Using wrong relation"
W2_Tdp=(T1+273)*RH1-273 "Using wrong relation"
W3_Tdp=WETBULB(AirH2O,T=T1,P=P1,R=RH1); P1=100 "Using wet-bulb temperature"

The Air in a House Is at 25°C and 72