= = Showering often causes tropical conditions in the bathroom (state 1: t1 = 30 C, 91 = 0.9). After some time, the air in the bathroom cooled down (isobaric, p= 1 bar) to the state 2 with 12 = 20 C and x3s = 14.9 g/kgair (saturation water content at t2). As a result, condensate is formed and runs down the window to the floor. By this change of state ( 12), heat Q = 30 kJ is extracted from the air and transferred through the window to the ambient. (2) (3) a) Determine the water content xi in state 1. b) Determine the condensation temperature tc, at which the window starts to steam up. c) Determine the mass of dry air mir being cooled down, and the mass M-12 of the condensate. (5) 5) = Rair = 287.11 J/(kg-K) Rw = 461.50 J/(kg-K) CpAir = 1.004 kJ/(kg:K) Cpw = 1.86 kJ/(kg-K) Cu = 4.19 kJ/(kg:K) 10 = 2500 kJ/kg Saturation pressure of water: t/C 16 18 18.2 20.6 20 22 24 26 28 30 32 ps / mbar 23.4 26.5 29.9 33.6 37.8 42.5 47.6