diff --git a/src/postProcessing/functionObjects/field/Make/files b/src/postProcessing/functionObjects/field/Make/files
index 0abf314f96..f0223c3f94 100644
--- a/src/postProcessing/functionObjects/field/Make/files
+++ b/src/postProcessing/functionObjects/field/Make/files
@@ -14,6 +14,8 @@ fieldValues/faceSource/faceSource.C
 fieldValues/faceSource/faceSourceFunctionObject.C
 fieldValues/cellSource/cellSource.C
 fieldValues/cellSource/cellSourceFunctionObject.C
+fieldValues/faceSourceDelta/faceSourceDelta.C
+fieldValues/faceSourceDelta/faceSourceDeltaFunctionObject.C
 
 nearWallFields/nearWallFields.C
 nearWallFields/nearWallFieldsFunctionObject.C
diff --git a/src/postProcessing/functionObjects/field/fieldValues/faceSourceDelta/IOfaceSourceDelta.H b/src/postProcessing/functionObjects/field/fieldValues/faceSourceDelta/IOfaceSourceDelta.H
new file mode 100644
index 0000000000..3dbf93f1ca
--- /dev/null
+++ b/src/postProcessing/functionObjects/field/fieldValues/faceSourceDelta/IOfaceSourceDelta.H
@@ -0,0 +1,50 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | Copyright (C) 2012 OpenFOAM Foundation
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+Typedef
+    Foam::IOfaceSourceDelta
+
+
+Description
+    Instance of the generic IOOutputFilter for faceSourceDelta.
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef IOfaceSourceDelta_H
+#define IOfaceSourceDelta_H
+
+#include "faceSourceDelta.H"
+#include "IOOutputFilter.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+    typedef IOOutputFilter<faceSourceDelta> IOfaceSourceDelta;
+}
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //
diff --git a/src/postProcessing/functionObjects/field/fieldValues/faceSourceDelta/faceSourceDelta.C b/src/postProcessing/functionObjects/field/fieldValues/faceSourceDelta/faceSourceDelta.C
new file mode 100644
index 0000000000..22af9e4afe
--- /dev/null
+++ b/src/postProcessing/functionObjects/field/fieldValues/faceSourceDelta/faceSourceDelta.C
@@ -0,0 +1,176 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | Copyright (C) 2012 OpenFOAM Foundation
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "faceSourceDelta.H"
+#include "ListOps.H"
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+defineTypeNameAndDebug(Foam::fieldValues::faceSourceDelta, 0);
+
+// * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * * //
+
+void Foam::fieldValues::faceSourceDelta::updateMesh(const mapPolyMesh&)
+{
+    // Do nothing
+}
+
+
+void Foam::fieldValues::faceSourceDelta::movePoints(const Field<point>&)
+{
+    // Do nothing
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::fieldValues::faceSourceDelta::faceSourceDelta
+(
+    const word& name,
+    const objectRegistry& obr,
+    const dictionary& dict,
+    const bool loadFromFiles
+)
+:
+    functionObjectFile(obr, name, typeName),
+    obr_(obr),
+    log_(false),
+    faceSource1_
+    (
+        name + ".faceSource1",
+        obr,
+        dict.subDict("faceSource1"),
+        loadFromFiles
+    ),
+    faceSource2_
+    (
+        name + ".faceSource2",
+        obr,
+        dict.subDict("faceSource2"),
+        loadFromFiles
+    )
+{
+    read(dict);
+}
+
+
+void Foam::fieldValues::faceSourceDelta::writeFileHeader(const label i)
+{
+    const wordList& fields1 = faceSource1_.fields();
+    const wordList& fields2 = faceSource2_.fields();
+
+    DynamicList<word> commonFields(fields1.size());
+    forAll(fields1, i)
+    {
+        label index = findIndex(fields2, fields1[i]);
+        if (index != -1)
+        {
+            commonFields.append(fields1[i]);
+        }
+    }
+
+    file() << "# Time";
+
+    forAll(commonFields, i)
+    {
+        file()<< tab << commonFields[i];
+    }
+
+    file() << endl;
+}
+
+
+// * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //
+
+Foam::fieldValues::faceSourceDelta::~faceSourceDelta()
+{}
+
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+void Foam::fieldValues::faceSourceDelta::read(const dictionary& dict)
+{
+    log_ = dict.lookupOrDefault<Switch>("log", false);
+    faceSource1_.read(dict.subDict("faceSource1"));
+    faceSource2_.read(dict.subDict("faceSource2"));
+}
+
+
+void Foam::fieldValues::faceSourceDelta::write()
+{
+    functionObjectFile::write();
+
+    faceSource1_.write();
+    faceSource2_.write();
+
+    if (Pstream::master())
+    {
+        file()<< obr_.time().timeName();
+    }
+
+    if (log_)
+    {
+        Info<< type() << " output:" << endl;
+    }
+
+    bool found = false;
+    processFields<scalar>(found);
+    processFields<vector>(found);
+    processFields<sphericalTensor>(found);
+    processFields<symmTensor>(found);
+    processFields<tensor>(found);
+
+    if (Pstream::master())
+    {
+        file()<< endl;
+    }
+
+    if (log_)
+    {
+        if (!found)
+        {
+            Info<< "    none" << endl;
+        }
+        else
+        {
+            Info<< endl;
+        }
+    }
+}
+
+
+void Foam::fieldValues::faceSourceDelta::execute()
+{
+    // Do nothing
+}
+
+
+void Foam::fieldValues::faceSourceDelta::end()
+{
+    // Do nothing
+}
+
+
+// ************************************************************************* //
diff --git a/src/postProcessing/functionObjects/field/fieldValues/faceSourceDelta/faceSourceDelta.H b/src/postProcessing/functionObjects/field/fieldValues/faceSourceDelta/faceSourceDelta.H
new file mode 100644
index 0000000000..ba97b9e5a5
--- /dev/null
+++ b/src/postProcessing/functionObjects/field/fieldValues/faceSourceDelta/faceSourceDelta.H
@@ -0,0 +1,179 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | Copyright (C) 2012 OpenFOAM Foundation
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+Class
+    Foam::fieldValues::faceSourceDelta
+
+Group
+    grpFieldFunctionObjects
+
+Description
+    This function object provides a differencing option between two 'face
+    source' function objects.
+
+    Example of function object specification:
+    \verbatim
+    faceSourceDelta1
+    {
+        type            faceSourceDelta;
+        functionObjectLibs ("libfieldFunctionObjects.so");
+        faceSource1
+        {
+            ...
+        }
+        faceSource2
+        {
+            ...
+        }
+    }
+    \endverbatim
+
+    \heading Function object usage
+    \table
+        Property     | Description             | Required    | Default value
+        type         | type name: faceSourceDelta   | yes    |
+    \endtable
+
+SeeAlso
+    Foam::faceSource
+
+SourceFiles
+    faceSourceDelta.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef faceSourceDelta_H
+#define faceSourceDelta_H
+
+#include "functionObjectFile.H"
+#include "faceSource.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+namespace fieldValues
+{
+
+/*---------------------------------------------------------------------------*\
+                       Class faceSourceDelta Declaration
+\*---------------------------------------------------------------------------*/
+
+class faceSourceDelta
+:
+    public functionObjectFile
+{
+
+private:
+
+    // Private data
+
+        //- Database this class is registered to
+        const objectRegistry& obr_;
+
+        //- Switch to send output to Info as well as to file
+        Switch log_;
+
+        //- Face source 1
+        faceSource faceSource1_;
+
+        //- Face source 2
+        faceSource faceSource2_;
+
+
+    // Private Member Functions
+
+        //- Templated function to process common fields
+        template<class Type>
+        void processFields(bool& found);
+
+
+protected:
+
+    // Functions to be over-ridden from IOoutputFilter class
+
+        //- Update mesh
+        virtual void updateMesh(const mapPolyMesh&);
+
+        //- Move points
+        virtual void movePoints(const Field<point>&);
+
+        //- Output file header information
+        virtual void writeFileHeader(const label i);
+
+
+public:
+
+    //- Run-time type information
+    TypeName("faceSourceDelta");
+
+
+    //- Construct from components
+    faceSourceDelta
+    (
+        const word& name,
+        const objectRegistry& obr,
+        const dictionary& dict,
+        const bool loadFromFiles = false
+    );
+
+
+    //- Destructor
+    virtual ~faceSourceDelta();
+
+
+    // Public Member Functions
+
+        // Function object functions
+
+            //- Read from dictionary
+            virtual void read(const dictionary&);
+
+            //- Calculate and write
+            virtual void write();
+
+            //- Execute
+            virtual void execute();
+
+            //- Execute the at the final time-loop, currently does nothing
+            virtual void end();
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace fieldValues
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#ifdef NoRepository
+    #include "faceSourceDeltaTemplates.C"
+#endif
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //
diff --git a/src/postProcessing/functionObjects/field/fieldValues/faceSourceDelta/faceSourceDeltaFunctionObject.C b/src/postProcessing/functionObjects/field/fieldValues/faceSourceDelta/faceSourceDeltaFunctionObject.C
new file mode 100644
index 0000000000..aec39668b5
--- /dev/null
+++ b/src/postProcessing/functionObjects/field/fieldValues/faceSourceDelta/faceSourceDeltaFunctionObject.C
@@ -0,0 +1,46 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | Copyright (C) 2012 OpenFOAM Foundation
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "faceSourceDeltaFunctionObject.H"
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+namespace Foam
+{
+    defineNamedTemplateTypeNameAndDebug
+    (
+        faceSourceDeltaFunctionObject,
+        0
+    );
+
+    addToRunTimeSelectionTable
+    (
+        functionObject,
+        faceSourceDeltaFunctionObject,
+        dictionary
+    );
+}
+
+// ************************************************************************* //
diff --git a/src/postProcessing/functionObjects/field/fieldValues/faceSourceDelta/faceSourceDeltaFunctionObject.H b/src/postProcessing/functionObjects/field/fieldValues/faceSourceDelta/faceSourceDeltaFunctionObject.H
new file mode 100644
index 0000000000..ceca4b9938
--- /dev/null
+++ b/src/postProcessing/functionObjects/field/fieldValues/faceSourceDelta/faceSourceDeltaFunctionObject.H
@@ -0,0 +1,54 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | Copyright (C) 2012 OpenFOAM Foundation
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+Typedef
+    Foam::faceSourceDeltaFunctionObject
+
+Description
+    FunctionObject wrapper around faceSourceDelta to allow it to be
+    created via the functions entry within controlDict.
+
+SourceFiles
+    faceSourceDeltaFunctionObject.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef faceSourceDeltaFunctionObject_H
+#define faceSourceDeltaFunctionObject_H
+
+#include "faceSourceDelta.H"
+#include "OutputFilterFunctionObject.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+    typedef OutputFilterFunctionObject<fieldValues::faceSourceDelta>
+        faceSourceDeltaFunctionObject;
+}
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //
diff --git a/src/postProcessing/functionObjects/field/fieldValues/faceSourceDelta/faceSourceDeltaTemplates.C b/src/postProcessing/functionObjects/field/fieldValues/faceSourceDelta/faceSourceDeltaTemplates.C
new file mode 100644
index 0000000000..1cde69473e
--- /dev/null
+++ b/src/postProcessing/functionObjects/field/fieldValues/faceSourceDelta/faceSourceDeltaTemplates.C
@@ -0,0 +1,66 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | Copyright (C) 2012 OpenFOAM Foundation
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+template<class Type>
+void Foam::fieldValues::faceSourceDelta::processFields(bool& found)
+{
+    typedef GeometricField<Type, fvPatchField, volMesh> vf;
+
+    const wordList& fields1 = faceSource1_.fields();
+
+    const dictionary& results1 = faceSource1_.resultDict();
+    const dictionary& results2 = faceSource2_.resultDict();
+
+    Type r1(pTraits<Type>::zero);
+    Type r2(pTraits<Type>::zero);
+
+    forAll(fields1, i)
+    {
+        const word& fieldName = fields1[i];
+        if (obr_.foundObject<vf>(fieldName) && results2.found(fieldName))
+        {
+            results1.lookup(fieldName) >> r1;
+            results2.lookup(fieldName) >> r2;
+
+            if (log_)
+            {
+                Info<< "    field: " << fieldName << ", delta: " << r2 - r1
+                    << endl;
+            }
+
+            if (Pstream::master())
+            {
+                file()<< tab << r2 - r1;
+            }
+
+            found = true;
+        }
+    }
+}
+
+
+// ************************************************************************* //