diff --git a/src/postProcessing/functionObjects/field/fieldValues/cellSource/cellSource.C b/src/postProcessing/functionObjects/field/fieldValues/cellSource/cellSource.C
index 9d65cefc57..97cd9393bd 100644
--- a/src/postProcessing/functionObjects/field/fieldValues/cellSource/cellSource.C
+++ b/src/postProcessing/functionObjects/field/fieldValues/cellSource/cellSource.C
@@ -80,10 +80,11 @@ void Foam::fieldValues::cellSource::setCellZoneCells()
     }
 
     cellId_.setSize(count);
+    nCells_ = returnReduce(cellId_.size(), sumOp<label>());
 
     if (debug)
     {
-        Info<< "Original cell zone size = " << cZone.size()
+        Pout<< "Original cell zone size = " << cZone.size()
             << ", new size = " << count << endl;
     }
 }
@@ -109,8 +110,8 @@ void Foam::fieldValues::cellSource::initialise(const dictionary& dict)
     }
 
     Info<< type() << " " << name_ << ":" << nl
-        << "    total cells  = " << cellId_.size() << nl
-        << "    total volume = " << sum(filterField(mesh().V()))
+        << "    total cells  = " << nCells_ << nl
+        << "    total volume = " << gSum(filterField(mesh().V()))
         << nl << endl;
 
     if (operation_ == opWeightedAverage)
@@ -144,7 +145,7 @@ void Foam::fieldValues::cellSource::writeFileHeader()
     {
         outputFilePtr_()
             << "# Source : " << sourceTypeNames_[source_] << " "
-            << sourceName_ <<  nl << "# Cells  : " << cellId_.size() << nl
+            << sourceName_ <<  nl << "# Cells  : " << nCells_ << nl
             << "# Time" << tab << "sum(V)";
 
         forAll(fields_, i)
@@ -172,6 +173,7 @@ Foam::fieldValues::cellSource::cellSource
     fieldValue(name, obr, dict, loadFromFiles),
     source_(sourceTypeNames_.read(dict.lookup("source"))),
     operation_(operationTypeNames_.read(dict.lookup("operation"))),
+    nCells_(0),
     cellId_()
 {
     read(dict);
diff --git a/src/postProcessing/functionObjects/field/fieldValues/cellSource/cellSource.H b/src/postProcessing/functionObjects/field/fieldValues/cellSource/cellSource.H
index 8108f7891c..c271a1c997 100644
--- a/src/postProcessing/functionObjects/field/fieldValues/cellSource/cellSource.H
+++ b/src/postProcessing/functionObjects/field/fieldValues/cellSource/cellSource.H
@@ -133,6 +133,9 @@ protected:
         //- Operation to apply to values
         operationType operation_;
 
+        //- Global number of cells
+        label nCells_;
+
         //- Local list of cell IDs
         labelList cellId_;
 
diff --git a/src/postProcessing/functionObjects/field/fieldValues/faceSource/faceSource.C b/src/postProcessing/functionObjects/field/fieldValues/faceSource/faceSource.C
index b6788e1af2..e19a80dc2a 100644
--- a/src/postProcessing/functionObjects/field/fieldValues/faceSource/faceSource.C
+++ b/src/postProcessing/functionObjects/field/fieldValues/faceSource/faceSource.C
@@ -78,7 +78,7 @@ void Foam::fieldValues::faceSource::setFaceZoneFaces()
 
     faceId_.setSize(fZone.size());
     facePatchId_.setSize(fZone.size());
-    flipMap_.setSize(fZone.size());
+    faceSign_.setSize(fZone.size());
 
     label count = 0;
     forAll(fZone, i)
@@ -134,11 +134,11 @@ void Foam::fieldValues::faceSource::setFaceZoneFaces()
         {
             if (fZone.flipMap()[i])
             {
-                flipMap_[count] = -1;
+                faceSign_[count] = -1;
             }
             else
             {
-                flipMap_[count] = 1;
+                faceSign_[count] = 1;
             }
             faceId_[count] = faceId;
             facePatchId_[count] = facePatchId;
@@ -148,11 +148,12 @@ void Foam::fieldValues::faceSource::setFaceZoneFaces()
 
     faceId_.setSize(count);
     facePatchId_.setSize(count);
-    flipMap_.setSize(count);
+    faceSign_.setSize(count);
+    nFaces_ = returnReduce(faceId_.size(), sumOp<label>());
 
     if (debug)
     {
-        Info<< "Original face zone size = " << fZone.size()
+        Pout<< "Original face zone size = " << fZone.size()
             << ", new size = " << count << endl;
     }
 }
@@ -187,13 +188,14 @@ void Foam::fieldValues::faceSource::setPatchFaces()
 
     faceId_.setSize(nFaces);
     facePatchId_.setSize(nFaces);
-    flipMap_.setSize(nFaces);
+    faceSign_.setSize(nFaces);
+    nFaces_ = returnReduce(faceId_.size(), sumOp<label>());
 
     forAll(faceId_, faceI)
     {
         faceId_[faceI] = faceI;
         facePatchId_[faceI] = patchId;
-        flipMap_[faceI] = 1;
+        faceSign_[faceI] = 1;
     }
 }
 
@@ -216,7 +218,7 @@ void Foam::fieldValues::faceSource::initialise(const dictionary& dict)
         }
         default:
         {
-            FatalErrorIn("faceSource::initiliase()")
+            FatalErrorIn("faceSource::initialise()")
                 << type() << " " << name_ << ": "
                 << sourceTypeNames_[source_] << "(" << sourceName_ << "):"
                 << nl << "    Unknown source type. Valid source types are:"
@@ -225,8 +227,10 @@ void Foam::fieldValues::faceSource::initialise(const dictionary& dict)
     }
 
     Info<< type() << " " << name_ << ":" << nl
-        << "    total faces  = " << faceId_.size() << nl
-        << "    total area   = " << sum(filterField(mesh().magSf())) << nl;
+        << "    total faces  = " << nFaces_
+        << nl
+        << "    total area   = " << gSum(filterField(mesh().magSf(), false))
+        << nl;
 
     if (operation_ == opWeightedAverage)
     {
@@ -260,7 +264,7 @@ void Foam::fieldValues::faceSource::writeFileHeader()
     {
         outputFilePtr_()
             << "# Source : " << sourceTypeNames_[source_] << " "
-            << sourceName_ <<  nl << "# Faces  : " << faceId_.size() << nl
+            << sourceName_ <<  nl << "# Faces  : " << nFaces_ << nl
             << "# Time" << tab << "sum(magSf)";
 
         forAll(fields_, i)
@@ -288,9 +292,10 @@ Foam::fieldValues::faceSource::faceSource
     fieldValue(name, obr, dict, loadFromFiles),
     source_(sourceTypeNames_.read(dict.lookup("source"))),
     operation_(operationTypeNames_.read(dict.lookup("operation"))),
+    nFaces_(0),
     faceId_(),
     facePatchId_(),
-    flipMap_(),
+    faceSign_(),
     weightFieldName_("undefinedWeightedFieldName")
 {
     read(dict);
@@ -326,7 +331,7 @@ void Foam::fieldValues::faceSource::write()
         {
             outputFilePtr_()
                 << obr_.time().value() << tab
-                << sum(filterField(mesh().magSf()));
+                << sum(filterField(mesh().magSf(), false));
         }
 
         forAll(fields_, i)
diff --git a/src/postProcessing/functionObjects/field/fieldValues/faceSource/faceSource.H b/src/postProcessing/functionObjects/field/fieldValues/faceSource/faceSource.H
index e80e1b31ea..dc3d092334 100644
--- a/src/postProcessing/functionObjects/field/fieldValues/faceSource/faceSource.H
+++ b/src/postProcessing/functionObjects/field/fieldValues/faceSource/faceSource.H
@@ -53,6 +53,15 @@ Description
       - areaAverage
       - areaIntegrate
       - weightedAverage
+      - min
+      - max
+
+    Notes:
+    - faces on empty patches get ignored
+    - if the field is a volField the faceZone can only consist of boundary
+    faces.
+    - all fields get oriented according to the faceZone (so you might e.g. see
+    negative pressure)
 
 SourceFiles
     faceSource.C
@@ -64,7 +73,6 @@ SourceFiles
 
 #include "NamedEnum.H"
 #include "fieldValue.H"
-#include "labelList.H"
 #include "surfaceFieldsFwd.H"
 #include "volFieldsFwd.H"
 
@@ -136,14 +144,17 @@ protected:
         //- Operation to apply to values
         operationType operation_;
 
+        //- Global number of faces
+        label nFaces_;
+
         //- Local list of face IDs
         labelList faceId_;
 
         //- Local list of patch ID per face
         labelList facePatchId_;
 
-        //- List of +1/-1 representing face flip map
-        labelList flipMap_;
+        //- List of +1/-1 representing face flip map (1 use as is, -1 negate)
+        labelList faceSign_;
 
         //- Weight field name - only used for opWeightedAverage mode
         word weightFieldName_;
@@ -209,7 +220,7 @@ public:
             inline const labelList& facePatch() const;
 
             //- Return the list of +1/-1 representing face flip map
-            inline const labelList& flipMap() const;
+            inline const labelList& faceSign() const;
 
 
         // Function object functions
@@ -228,14 +239,16 @@ public:
             template<class Type>
             tmp<Field<Type> > filterField
             (
-                const GeometricField<Type, fvsPatchField, surfaceMesh>& field
+                const GeometricField<Type, fvsPatchField, surfaceMesh>& field,
+                const bool applyOrientation
             ) const;
 
             //- Filter a volume field according to faceIds
             template<class Type>
             tmp<Field<Type> > filterField
             (
-                const GeometricField<Type, fvPatchField, volMesh>& field
+                const GeometricField<Type, fvPatchField, volMesh>& field,
+                const bool applyOrientation
             ) const;
 };
 
diff --git a/src/postProcessing/functionObjects/field/fieldValues/faceSource/faceSourceI.H b/src/postProcessing/functionObjects/field/fieldValues/faceSource/faceSourceI.H
index 18ab0766eb..2ef320febb 100644
--- a/src/postProcessing/functionObjects/field/fieldValues/faceSource/faceSourceI.H
+++ b/src/postProcessing/functionObjects/field/fieldValues/faceSource/faceSourceI.H
@@ -49,9 +49,9 @@ Foam::fieldValues::faceSource::facePatch() const
 
 
 inline const Foam::labelList&
-Foam::fieldValues::faceSource::flipMap() const
+Foam::fieldValues::faceSource::faceSign() const
 {
-    return flipMap_;
+    return faceSign_;
 }
 
 
diff --git a/src/postProcessing/functionObjects/field/fieldValues/faceSource/faceSourceTemplates.C b/src/postProcessing/functionObjects/field/fieldValues/faceSource/faceSourceTemplates.C
index 7c9ab9dbec..dfa293a082 100644
--- a/src/postProcessing/functionObjects/field/fieldValues/faceSource/faceSourceTemplates.C
+++ b/src/postProcessing/functionObjects/field/fieldValues/faceSource/faceSourceTemplates.C
@@ -60,14 +60,14 @@ Foam::tmp<Foam::Field<Type> > Foam::fieldValues::faceSource::setFieldValues
 
     if (obr_.foundObject<sf>(fieldName))
     {
-        return filterField(obr_.lookupObject<sf>(fieldName));
+        return filterField(obr_.lookupObject<sf>(fieldName), true);
     }
     else if (obr_.foundObject<vf>(fieldName))
     {
-        return filterField(obr_.lookupObject<vf>(fieldName));
+        return filterField(obr_.lookupObject<vf>(fieldName), true);
     }
 
-    return tmp<Field<Type> >(new Field<Type>(0.0));
+    return tmp<Field<Type> >(new Field<Type>(0));
 }
 
 
@@ -131,10 +131,13 @@ bool Foam::fieldValues::faceSource::writeValues(const word& fieldName)
 
     if (ok)
     {
+        // Get (correctly oriented) field
         Field<Type> values = combineFields(setFieldValues<Type>(fieldName));
 
-        scalarField magSf = combineFields(filterField(mesh().magSf()));
+        // Get unoriented magSf
+        scalarField magSf = combineFields(filterField(mesh().magSf(), false));
 
+        // Get (correctly oriented) weighting field
         scalarField weightField =
             combineFields(setFieldValues<scalar>(weightFieldName_));
 
@@ -177,7 +180,8 @@ bool Foam::fieldValues::faceSource::writeValues(const word& fieldName)
 template<class Type>
 Foam::tmp<Foam::Field<Type> > Foam::fieldValues::faceSource::filterField
 (
-    const GeometricField<Type, fvPatchField, volMesh>& field
+    const GeometricField<Type, fvPatchField, volMesh>& field,
+    const bool applyOrientation
 ) const
 {
     tmp<Field<Type> > tvalues(new Field<Type>(faceId_.size()));
@@ -205,8 +209,14 @@ Foam::tmp<Foam::Field<Type> > Foam::fieldValues::faceSource::filterField
                 << "    Unable to process internal faces for volume field "
                 << field.name() << nl << abort(FatalError);
         }
+    }
 
-        values[i] *= flipMap_[i];
+    if (applyOrientation)
+    {
+        forAll(values, i)
+        {
+            values[i] *= faceSign_[i];
+        }
     }
 
     return tvalues;
@@ -216,7 +226,8 @@ Foam::tmp<Foam::Field<Type> > Foam::fieldValues::faceSource::filterField
 template<class Type>
 Foam::tmp<Foam::Field<Type> > Foam::fieldValues::faceSource::filterField
 (
-    const GeometricField<Type, fvsPatchField, surfaceMesh>& field
+    const GeometricField<Type, fvsPatchField, surfaceMesh>& field,
+    const bool applyOrientation
 ) const
 {
     tmp<Field<Type> > tvalues(new Field<Type>(faceId_.size()));
@@ -234,8 +245,14 @@ Foam::tmp<Foam::Field<Type> > Foam::fieldValues::faceSource::filterField
         {
             values[i] = field[faceI];
         }
+    }
 
-        values[i] *= flipMap_[i];
+    if (applyOrientation)
+    {
+        forAll(values, i)
+        {
+            values[i] *= faceSign_[i];
+        }
     }
 
     return tvalues;