Given:
Wall's inside temperature, [tex]T_{wa} = 15^{\circ}C[/tex]
Room air temperature, [tex]T_{air} = 21^{\circ}C[/tex]
Solution:
To calculate percentage max relative humidity, we make use of steam table for saturated pressure of wall and air:
From steam table:
At [tex]T_{wa} = 15^{\circ}C[/tex]:
[tex]P_{wa(sat)} = 1.7057 kPa[/tex]
At [tex]T_{air} = 21^{\circ}C[/tex]:
[tex]P_{air(sat)} = 2.487 kPa[/tex]
Now,
[tex]% Relative Humidity (RH)_{max} = \frac{P_{wa(sat)}}{P_{air(sat)}} \times 100[/tex]
[tex](RH)_{max} = \frac{1.7057}{2.487}\times 100[/tex]
(RH)_{max} = 68.58%
Therefore, max Relative Humidity of the air before the occurrence of condensation in wall is 68.85%
