% Units
atm = 101325 ; % [Pa]
kJ  = 1000   ; % [J]

% Functions for saturation & absolute humidity
p_sat = @(t) 610.5 * exp( 17.269*t / (237.3+t) ) ; % [Pa]
t_sat = @(p) 237.3 / ( 17.269/log(p/610.5)-1 ) ;   % [°C]
w     = @(p_vap, p) 0.622 * p_vap / (p-p_vap) ;    % [kg_vap/kg_as]
p_vap = @(w, p) p / ( 0.622 / w + 1 ) ;            % [Pa]

% Total mass
m = 1 ;     % [kg_as]

% State 1
p1   = 1*atm ; % [Pa]
t1   = 30   ;  % [°C]
phi1 = 0.70 ;  % [-]

% State 2
p2   = p1 ; % [Pa]
t2   = 5  ; % [°C]

% Dew temperature 1
p_vap1 = phi1 * p_sat(t1) 
t_dew1 = t_sat(p_vap1) 

% Liquid water
w1 = w(p_vap1, p1) 
m_as = m / ( 1 + w1 ) 
p_vap2 = p_sat(t2) 
w2 = w(p_vap2, p2) 
m_liq = m_as * (w1-w2)