diff --git a/src/regionModels/surfaceFilmModels/submodels/thermo/phaseChangeModel/standardPhaseChange/standardPhaseChange.C b/src/regionModels/surfaceFilmModels/submodels/thermo/phaseChangeModel/standardPhaseChange/standardPhaseChange.C
index c9f03a7bd2fd5c333011ed8316ec9a1ee1d5c958..95e9fcddf6d8936da023b4ff4a0a43cefd7b0e8f 100644
--- a/src/regionModels/surfaceFilmModels/submodels/thermo/phaseChangeModel/standardPhaseChange/standardPhaseChange.C
+++ b/src/regionModels/surfaceFilmModels/submodels/thermo/phaseChangeModel/standardPhaseChange/standardPhaseChange.C
@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2018 OpenFOAM Foundation
-    Copyright (C) 2020 OpenCFD Ltd.
+    Copyright (C) 2020-2022 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -82,7 +82,7 @@ standardPhaseChange::standardPhaseChange
     deltaMin_(coeffDict_.get<scalar>("deltaMin")),
     L_(coeffDict_.get<scalar>("L")),
     TbFactor_(coeffDict_.getOrDefault<scalar>("TbFactor", 1.1)),
-    YInfZero_(coeffDict_.getOrDefault<Switch>("YInfZero", false))
+    YInfZero_(coeffDict_.getOrDefault("YInfZero", false))
 {}
 
 
@@ -95,7 +95,7 @@ void standardPhaseChange::correctModel
     scalarField& availableMass,
     scalarField& dMass,
     scalarField& dEnergy,
-    YInfType YInf
+    const YInfType& YInf
 )
 {
     const thermoSingleLayer& film = filmType<thermoSingleLayer>();
diff --git a/src/regionModels/surfaceFilmModels/submodels/thermo/phaseChangeModel/standardPhaseChange/standardPhaseChange.H b/src/regionModels/surfaceFilmModels/submodels/thermo/phaseChangeModel/standardPhaseChange/standardPhaseChange.H
index 8f131df48b4658712ac7fae2713e451bed1470e7..cd1f4d1bb2998ebee2626330e0f68a3664e7a566 100644
--- a/src/regionModels/surfaceFilmModels/submodels/thermo/phaseChangeModel/standardPhaseChange/standardPhaseChange.H
+++ b/src/regionModels/surfaceFilmModels/submodels/thermo/phaseChangeModel/standardPhaseChange/standardPhaseChange.H
@@ -34,8 +34,8 @@ SourceFiles
 
 \*---------------------------------------------------------------------------*/
 
-#ifndef standardPhaseChange_H
-#define standardPhaseChange_H
+#ifndef Foam_standardPhaseChange_H
+#define Foam_standardPhaseChange_H
 
 #include "phaseChangeModel.H"
 
@@ -58,7 +58,7 @@ class standardPhaseChange
 {
 protected:
 
-    // Protected data
+    // Protected Data
 
         //- Minimum film height for model to be active
         const scalar deltaMin_;
@@ -71,7 +71,7 @@ protected:
         const scalar TbFactor_;
 
         //- Switch to treat YInf as zero
-        Switch YInfZero_;
+        bool YInfZero_;
 
 
     // Protected member functions
@@ -86,7 +86,7 @@ protected:
             scalarField& availableMass,
             scalarField& dMass,
             scalarField& dEnergy,
-            YInfType YInf
+            const YInfType& YInf
         );
 
         //- No copy construct
diff --git a/src/regionModels/surfaceFilmModels/submodels/thermo/phaseChangeModel/waxSolventEvaporation/waxSolventEvaporation.C b/src/regionModels/surfaceFilmModels/submodels/thermo/phaseChangeModel/waxSolventEvaporation/waxSolventEvaporation.C
index 376d29b3ffbcbda4a62ae10a010b5ed330dda559..0b20fe648f627469d71d9305cdf7ba44a7446445 100644
--- a/src/regionModels/surfaceFilmModels/submodels/thermo/phaseChangeModel/waxSolventEvaporation/waxSolventEvaporation.C
+++ b/src/regionModels/surfaceFilmModels/submodels/thermo/phaseChangeModel/waxSolventEvaporation/waxSolventEvaporation.C
@@ -153,7 +153,7 @@ void waxSolventEvaporation::correctModel
     scalarField& availableMass,
     scalarField& dMass,
     scalarField& dEnergy,
-    YInfType YInf
+    const YInfType& YInf
 )
 {
     const thermoSingleLayer& film = filmType<thermoSingleLayer>();
diff --git a/src/regionModels/surfaceFilmModels/submodels/thermo/phaseChangeModel/waxSolventEvaporation/waxSolventEvaporation.H b/src/regionModels/surfaceFilmModels/submodels/thermo/phaseChangeModel/waxSolventEvaporation/waxSolventEvaporation.H
index a34cb4cc44f0b47b421fc897157705783bf042cd..ef7a2c5511e5dfc06ff6340b2917244631ad999c 100644
--- a/src/regionModels/surfaceFilmModels/submodels/thermo/phaseChangeModel/waxSolventEvaporation/waxSolventEvaporation.H
+++ b/src/regionModels/surfaceFilmModels/submodels/thermo/phaseChangeModel/waxSolventEvaporation/waxSolventEvaporation.H
@@ -34,8 +34,8 @@ SourceFiles
 
 \*---------------------------------------------------------------------------*/
 
-#ifndef waxSolventEvaporation_H
-#define waxSolventEvaporation_H
+#ifndef Foam_waxSolventEvaporation_H
+#define Foam_waxSolventEvaporation_H
 
 #include "phaseChangeModel.H"
 #include "uniformDimensionedFields.H"
@@ -58,18 +58,9 @@ class waxSolventEvaporation
 :
     public phaseChangeModel
 {
-    // Private member functions
-
-        //- No copy construct
-        waxSolventEvaporation(const waxSolventEvaporation&) = delete;
-
-        //- No copy assignment
-        void operator=(const waxSolventEvaporation&) = delete;
-
-
 protected:
 
-    // Protected data
+    // Protected Data
 
         //- Molecular weight of wax [kg/kmol]
         uniformDimensionedScalarField Wwax_;
@@ -100,7 +91,7 @@ protected:
         autoPtr<Function1<scalar>> activityCoeff_;
 
 
-    // Protected member functions
+    // Protected Member Functions
 
         //- Return Sherwood number as a function of Reynolds and Schmidt numbers
         scalar Sh(const scalar Re, const scalar Sc) const;
@@ -112,9 +103,15 @@ protected:
             scalarField& availableMass,
             scalarField& dMass,
             scalarField& dEnergy,
-            YInfType YInf
+            const YInfType& YInf
         );
 
+        //- No copy construct
+        waxSolventEvaporation(const waxSolventEvaporation&) = delete;
+
+        //- No copy assignment
+        void operator=(const waxSolventEvaporation&) = delete;
+
 
 public: