An air$-$conditioning system operates at a total pressure of $1$ atm, $15\backslash$deg C$,$ and $60$percent relative humidity is first heated to $20\backslash$deg C in a heating section and thenhumidified by introducing water vapor. The air leaves the humidifying section at $25\backslash$deg C and $65$ percent relative humidity. Determine the amount of steam added to the air,and the amount of heat transfer to the air in the heating section.