diff --git a/MetroscopeModelingLibrary/Examples/CCGT/GasTurbine_direct.mo b/MetroscopeModelingLibrary/Examples/CCGT/GasTurbine_direct.mo
index fb3b28cf..213954fa 100644
--- a/MetroscopeModelingLibrary/Examples/CCGT/GasTurbine_direct.mo
+++ b/MetroscopeModelingLibrary/Examples/CCGT/GasTurbine_direct.mo
@@ -22,7 +22,7 @@ model GasTurbine_direct
   parameter Real combustionChamber_eta = 0.9999;
 
   // Inputs for calibration
-  output Units.NegativeMassFlowRate source_Q "kg/s";
+  output Units.PositiveMassFlowRate source_Q "kg/s";
   output Real compressor_P_out "barA";
   output Real compressor_T_out "degC";
   output Real W "MW";
@@ -68,7 +68,7 @@ equation
   source_fuel.P_out = P_fuel;
   source_fuel.h_out = h_fuel;
   source_fuel.Q_out = Q_fuel;
-  source_fuel.Xi_out = {0.90,0.05,0,0,0.025,0.025};
+  source_fuel.Xi_out = {0.80,0.05,0,0,0.025,0.025,0.1};
 
   // Parameters
   combustion_chamber.Kfr = combustion_chamber_Kfr;
diff --git a/MetroscopeModelingLibrary/Examples/CCGT/GasTurbine_reverse.mo b/MetroscopeModelingLibrary/Examples/CCGT/GasTurbine_reverse.mo
index 3d0334a7..55452837 100644
--- a/MetroscopeModelingLibrary/Examples/CCGT/GasTurbine_reverse.mo
+++ b/MetroscopeModelingLibrary/Examples/CCGT/GasTurbine_reverse.mo
@@ -22,7 +22,7 @@ model GasTurbine_reverse
   parameter Real combustionChamber_eta = 0.9999;
 
   // Inputs for calibration
-  input Units.NegativeMassFlowRate source_Q(start=500) "kg/s";
+  input Units.PositiveMassFlowRate source_Q(start=500) "kg/s";
   input Real compressor_P_out(start = 16) "barA";
   input Real compressor_T_out(start = 406) "degC";
   input Real W(start = 200) "MW";
@@ -68,7 +68,7 @@ equation
   source_fuel.P_out = P_fuel;
   source_fuel.h_out = h_fuel;
   source_fuel.Q_out = Q_fuel;
-  source_fuel.Xi_out = {0.90,0.05,0,0,0.025,0.025};
+  source_fuel.Xi_out = {0.80,0.05,0,0,0.025,0.025,0.1};
 
   // Parameters
   combustion_chamber.Kfr = combustion_chamber_Kfr;
diff --git a/MetroscopeModelingLibrary/Examples/CCGT/MetroscopiaCCGT/MetroscopiaCCGT_direct.mo b/MetroscopeModelingLibrary/Examples/CCGT/MetroscopiaCCGT/MetroscopiaCCGT_direct.mo
index e134ecda..748a39bd 100644
--- a/MetroscopeModelingLibrary/Examples/CCGT/MetroscopiaCCGT/MetroscopiaCCGT_direct.mo
+++ b/MetroscopeModelingLibrary/Examples/CCGT/MetroscopiaCCGT/MetroscopiaCCGT_direct.mo
@@ -693,7 +693,7 @@ equation
       Q_fuel_source_sensor.Q = Q_fuel_source;
       P_fuel_source_sensor.P_barA = P_fuel_source;
       T_fuel_source_sensor.T_degC = T_fuel_source;
-      source_fuel.Xi_out = {0.90,0.05,0,0,0.025,0.025};
+      source_fuel.Xi_out = {0.80,0.05,0,0,0.025,0.025,0.1};
 
     // Air Filter
       // Quantities definition
diff --git a/MetroscopeModelingLibrary/Examples/CCGT/MetroscopiaCCGT/MetroscopiaCCGT_reverse.mo b/MetroscopeModelingLibrary/Examples/CCGT/MetroscopiaCCGT/MetroscopiaCCGT_reverse.mo
index a3f03037..f8dd9374 100644
--- a/MetroscopeModelingLibrary/Examples/CCGT/MetroscopiaCCGT/MetroscopiaCCGT_reverse.mo
+++ b/MetroscopeModelingLibrary/Examples/CCGT/MetroscopiaCCGT/MetroscopiaCCGT_reverse.mo
@@ -399,7 +399,7 @@ equation
       Q_fuel_source_sensor.Q = Q_fuel_source;
       P_fuel_source_sensor.P_barA = P_fuel_source;
       T_fuel_source_sensor.T_degC = T_fuel_source;
-      source_fuel.Xi_out = {0.90,0.05,0,0,0.025,0.025};
+      source_fuel.Xi_out = {0.80,0.05,0,0,0.025,0.025,0.1};
 
     // Air Filter
       // Quantities definition
diff --git a/MetroscopeModelingLibrary/Fuel/BoundaryConditions/Source.mo b/MetroscopeModelingLibrary/Fuel/BoundaryConditions/Source.mo
index b49880a7..31c108a3 100644
--- a/MetroscopeModelingLibrary/Fuel/BoundaryConditions/Source.mo
+++ b/MetroscopeModelingLibrary/Fuel/BoundaryConditions/Source.mo
@@ -17,6 +17,8 @@ model Source
   Real amC4H10 "C4H10 molecular mass";
   Real amCO2 "CO2 molecular mass";
   Real amN2 "H2O molecular mass";
+  Real amH2 "H2 molecular mass";
+
 
   // Fuel composition
   Utilities.Units.MassFraction X_CH4(start=0.848);
@@ -25,6 +27,7 @@ model Source
   Utilities.Units.MassFraction X_C4H10_n_butane(start=0.00668);
   Utilities.Units.MassFraction X_N2(start=0.024);
   Utilities.Units.MassFraction X_CO2(start=0.025);
+  Utilities.Units.MassFraction X_H2(start=0.0);
 
   // Mole fractions
   Real X_molar_CH4(start=0.92);
@@ -33,6 +36,7 @@ model Source
   Real X_molar_C4H10_n_butane(start=0.002);
   Real X_molar_N2(start=0.015);
   Real X_molar_CO2(start=0.01);
+  Real X_molar_H2(start=0.0);
 
   // Mean molecular mass
   Real mean_molecular_mass(start=17);
@@ -46,6 +50,7 @@ equation
   amC4H10 = 4*amC + 10*amH;
   amN2 = 2*amN;
   amCO2 = amC + 2*amO;
+  amH2 = 2*amH;
 
   // Composition mass fraction
   X_CH4 = Xi_out[1]; // methane
@@ -54,6 +59,7 @@ equation
   X_C4H10_n_butane = Xi_out[4]; // butane
   X_N2 = Xi_out[5]; // nitrogen
   X_CO2 = Xi_out[6]; // carbon dioxyde
+  X_H2 = Xi_out[7]; // carbon dioxyde
 
   // Mean Molecular Mass: this gives the correct results only if the molar fraction is given as an input, if the mass fraction is given, this quantity is useless
   mean_molecular_mass = X_molar_CH4*amCH4 + X_molar_C2H6*amC2H6 + X_molar_C3H8*amC3H8 + X_molar_C4H10_n_butane*amC4H10 + X_molar_N2*amN2 + X_molar_CO2*amCO2;
@@ -65,6 +71,7 @@ equation
   X_molar_C4H10_n_butane = X_C4H10_n_butane/amC4H10 * mean_molecular_mass;
   X_molar_N2 = X_N2/amN2 * mean_molecular_mass;
   X_molar_CO2 = X_CO2/amCO2 * mean_molecular_mass;
+  X_molar_H2 = X_H2/amH2 * mean_molecular_mass;
 
   annotation (Icon(graphics={
         Ellipse(
diff --git a/MetroscopeModelingLibrary/MultiFluid/Machines/CombustionChamber.mo b/MetroscopeModelingLibrary/MultiFluid/Machines/CombustionChamber.mo
index 99753496..2cad8d2c 100644
--- a/MetroscopeModelingLibrary/MultiFluid/Machines/CombustionChamber.mo
+++ b/MetroscopeModelingLibrary/MultiFluid/Machines/CombustionChamber.mo
@@ -44,14 +44,15 @@ model CombustionChamber
   Units.MassFraction X_fuel_C4H10_n_butane(start=0.002);
   Units.MassFraction X_fuel_N2(start=0.015);
   Units.MassFraction X_fuel_CO2(start=0.01);
+  Units.MassFraction X_fuel_H2(start=0.01);
 
   Units.MassFraction X_fuel_C(start=0.8) "C mass fraction in the fuel";
   Units.MassFraction X_fuel_H(start=0.2) "H mass fraction in the fuel";
   Units.MassFraction X_fuel_O(start=0) "O mass fraction in the fuel";
 
   // Heating values
-  Units.SpecificEnthalpy HHV = (hhv_mass_CH4*X_fuel_CH4 + hhv_mass_C2H6*X_fuel_C2H6 + hhv_mass_C3H8*X_fuel_C3H8 + hhv_mass_C4H10*X_fuel_C4H10_n_butane)*1e6 "J/kg can be assigned in component modifiers";
-  Units.SpecificEnthalpy LHV = HHV - 2202.92069 *  m_H*(4*X_fuel_CH4/m_CH4 + 6*X_fuel_C2H6/m_C2H6 + 8*X_fuel_C3H8/m_C3H8 + 10*X_fuel_C4H10_n_butane/m_C4H10)*1e4 "J/kg can be assigned in component modifiers";
+  Units.SpecificEnthalpy HHV = (hhv_mass_H2*X_fuel_H2 + hhv_mass_CH4*X_fuel_CH4 + hhv_mass_C2H6*X_fuel_C2H6 + hhv_mass_C3H8*X_fuel_C3H8 + hhv_mass_C4H10*X_fuel_C4H10_n_butane)*1e6 "J/kg can be assigned in component modifiers";
+  Units.SpecificEnthalpy LHV = HHV - 2202.92069 *  X_fuel_H*1e4 "J/kg can be assigned in component modifiers";
 
   // Initialization parameters
   parameter Units.SpecificEnthalpy h_in_air_0 = 5e5;
@@ -72,10 +73,10 @@ equation
   Q_air = sink_air.Q_in;
   Q_fuel = sink_fuel.Q_in;
   Q_exhaust = - source_exhaust.Q_out;
+  h_exhaust = source_exhaust.h_out;
 
   h_in_air = sink_air.h_in;
   h_in_fuel = sink_fuel.h_in;
-  h_exhaust = source_exhaust.h_out;
 
   X_in_N2 = sink_air.Xi_in[1];
   X_in_O2 = sink_air.Xi_in[2];
@@ -89,6 +90,7 @@ equation
   X_fuel_C4H10_n_butane=  sink_fuel.Xi_in[4]; //butane
   X_fuel_N2=  sink_fuel.Xi_in[5]; // nitrogen
   X_fuel_CO2=  sink_fuel.Xi_in[6]; // carbon dioxyde
+  X_fuel_H2=  sink_fuel.Xi_in[7]; // hydrogen
 
   // Final quantities
   X_out_N2 = source_exhaust.Xi_out[1];
@@ -112,7 +114,7 @@ equation
   // Chemical balance
   // Quantity of reactants in fuel
   X_fuel_C  = m_C*(X_fuel_CH4/m_CH4 + 2*X_fuel_C2H6/m_C2H6 + 3*X_fuel_C3H8/m_C3H8 + 4*X_fuel_C4H10_n_butane/m_C4H10 + X_fuel_CO2/m_CO2);
-  X_fuel_H  = m_H*(4*X_fuel_CH4/m_CH4 + 6*X_fuel_C2H6/m_C2H6 + 8*X_fuel_C3H8/m_C3H8 + 10*X_fuel_C4H10_n_butane/m_C4H10);
+  X_fuel_H  = m_H*(2*X_fuel_H2/m_H2 + 4*X_fuel_CH4/m_CH4 + 6*X_fuel_C2H6/m_C2H6 + 8*X_fuel_C3H8/m_C3H8 + 10*X_fuel_C4H10_n_butane/m_C4H10);
   X_fuel_O = 2*m_O*X_fuel_CO2/m_CO2;
 
   // Mass balance for all species
@@ -131,11 +133,6 @@ equation
         preserveAspectRatio=false,
         extent={{-100,-100},{100,100}},
         grid={2,2})),
-    Window(
-      x=0.03,
-      y=0.02,
-      width=0.95,
-      height=0.95),
     Icon(coordinateSystem(
         preserveAspectRatio=false,
         extent={{-100,-100},{100,100}},
diff --git a/MetroscopeModelingLibrary/Tests/Multifluid/Machines/CombustionChamber.mo b/MetroscopeModelingLibrary/Tests/Multifluid/Machines/CombustionChamber.mo
index 045e3ed1..cbd5211f 100644
--- a/MetroscopeModelingLibrary/Tests/Multifluid/Machines/CombustionChamber.mo
+++ b/MetroscopeModelingLibrary/Tests/Multifluid/Machines/CombustionChamber.mo
@@ -33,14 +33,16 @@ equation
   source_air.Xi_out = {0.768,0.232,0.0,0.0,0.0};
 
   source_fuel.P_out = P_fuel;
-  source_fuel.h_out = h_fuel;
+  source_fuel.T_out = 160 + 273.15;
   source_fuel.Q_out = - Q_fuel;
-  source_fuel.X_molar_CH4=0.92;
+
+  source_fuel.X_molar_CH4=0.82;
   source_fuel.X_molar_C2H6=0.048;
   source_fuel.X_molar_C3H8=0.005;
   source_fuel.X_molar_C4H10_n_butane=0.002;
   source_fuel.X_molar_N2=0.015;
   source_fuel.X_molar_CO2=0.01;
+  source_fuel.X_molar_H2=0.1;
 
   // Parameters
   combustion_chamber.Kfr = combustion_chamber_Kfr;
diff --git a/MetroscopeModelingLibrary/Utilities/Constants/package.mo b/MetroscopeModelingLibrary/Utilities/Constants/package.mo
index 89f9df62..71fcaf56 100644
--- a/MetroscopeModelingLibrary/Utilities/Constants/package.mo
+++ b/MetroscopeModelingLibrary/Utilities/Constants/package.mo
@@ -38,6 +38,7 @@ package Constants "Stores all constants used in MML"
 
   // Atomic/Molecular masses
   final constant Units.AtomicMass m_H = 1.00798;
+  final constant Units.AtomicMass m_H2 = m_H*2;
   final constant Units.AtomicMass m_C = 12.0106;
   final constant Units.AtomicMass m_O = 15.9994;
   final constant Units.MolecularMass m_CH4 = m_C + m_H*4;
@@ -60,6 +61,27 @@ package Constants "Stores all constants used in MML"
   // n-Butane C4H10
   final constant Real hhv_molar_C4H10 = 2879.63 "kJ/mol";
   final constant Real hhv_mass_C4H10 = hhv_molar_C4H10/m_C4H10 "MJ/kg";
+  // Hydrogen H2
+  final constant Real hhv_molar_H2 = 286.13 "kJ/mol";
+  final constant Real hhv_mass_H2 = hhv_molar_H2/m_H2 "MJ/kg";
+
+
+  // Heating values: based on ISO 6976 at 25°C
+  // Methane CH4
+  final constant Real lhv_molar_CH4 = 802.69 "kJ/mol";
+  final constant Real lhv_mass_CH4 = lhv_molar_CH4/m_CH4 "MJ/kg";
+  // Ethane C2H6
+  final constant Real lhv_molar_C2H6 = 1428.83 "kJ/mol";
+  final constant Real lhv_mass_C2H6 = lhv_molar_C2H6/m_C2H6 "MJ/kg";
+  // Propane C3H8
+  final constant Real lhv_molar_C3H8 = 2043.35 "kJ/mol";
+  final constant Real lhv_mass_C3H8 = lhv_molar_C3H8/m_C3H8 "MJ/kg";
+  // n-Butane C4H10
+  final constant Real lhv_molar_C4H10 = 2657.58 "kJ/mol";
+  final constant Real lhv_mass_C4H10 = lhv_molar_C4H10/m_C4H10 "MJ/kg";
+  // Hydrogen H2
+  final constant Real lhv_molar_H2 = 241.72 "kJ/mol";
+  final constant Real lhv_mass_H2 = lhv_molar_H2/m_H2 "MJ/kg";
 
   annotation (
   Icon(coordinateSystem(extent={{-100.0,-100.0},{100.0,100.0}}), graphics={
diff --git a/MetroscopeModelingLibrary/Utilities/Constants/package.order b/MetroscopeModelingLibrary/Utilities/Constants/package.order
index f0bb5020..700b34e6 100644
--- a/MetroscopeModelingLibrary/Utilities/Constants/package.order
+++ b/MetroscopeModelingLibrary/Utilities/Constants/package.order
@@ -21,6 +21,7 @@ kgs_to_lbs
 kgs_to_Mlbh
 kgs_to_lbh
 m_H
+m_H2
 m_C
 m_O
 m_CH4
@@ -37,3 +38,15 @@ hhv_molar_C3H8
 hhv_mass_C3H8
 hhv_molar_C4H10
 hhv_mass_C4H10
+hhv_molar_H2
+hhv_mass_H2
+lhv_molar_CH4
+lhv_mass_CH4
+lhv_molar_C2H6
+lhv_mass_C2H6
+lhv_molar_C3H8
+lhv_mass_C3H8
+lhv_molar_C4H10
+lhv_mass_C4H10
+lhv_molar_H2
+lhv_mass_H2
diff --git a/MetroscopeModelingLibrary/Utilities/Media/FuelMedium/package.mo b/MetroscopeModelingLibrary/Utilities/Media/FuelMedium/package.mo
index 9cab6afe..97e28500 100644
--- a/MetroscopeModelingLibrary/Utilities/Media/FuelMedium/package.mo
+++ b/MetroscopeModelingLibrary/Utilities/Media/FuelMedium/package.mo
@@ -7,15 +7,17 @@ package FuelMedium
         Modelica.Media.IdealGases.Common.SingleGasesData.C3H8,
         Modelica.Media.IdealGases.Common.SingleGasesData.C4H10_n_butane,
         Modelica.Media.IdealGases.Common.SingleGasesData.N2,
-        Modelica.Media.IdealGases.Common.SingleGasesData.CO2},
+        Modelica.Media.IdealGases.Common.SingleGasesData.CO2,
+        Modelica.Media.IdealGases.Common.SingleGasesData.H2},
          fluidConstants={Modelica.Media.IdealGases.Common.FluidData.CH4,
            Modelica.Media.IdealGases.Common.FluidData.C2H6,
            Modelica.Media.IdealGases.Common.FluidData.C3H8,
            Modelica.Media.IdealGases.Common.FluidData.C4H10_n_butane,
            Modelica.Media.IdealGases.Common.FluidData.N2,
-           Modelica.Media.IdealGases.Common.FluidData.CO2},
-         substanceNames = {"Methane","Ethane","Propane","N-Butane,","Nitrogen","Carbondioxide"},
-         reference_X={0.92,0.048,0.005,0.002,0.015,0.01}) annotation(IconMap(primitivesVisible=false));
+           Modelica.Media.IdealGases.Common.FluidData.CO2,
+           Modelica.Media.IdealGases.Common.FluidData.H2},
+         substanceNames = {"Methane","Ethane","Propane","N-Butane,","Nitrogen","Carbondioxide","Hydrogen"},
+         reference_X={0.92,0.048,0.005,0.002,0.015,0.01,0.0}) annotation(IconMap(primitivesVisible=false));
 
   annotation (Icon(graphics={
         Rectangle(