diff --git a/src/finiteVolume/cfdTools/general/fieldSources/timeActivatedExplicitSource/TimeActivatedExplicitSource.C b/src/finiteVolume/cfdTools/general/fieldSources/timeActivatedExplicitSource/TimeActivatedExplicitSource.C
index b8fbe54a89..1873bbe3fe 100644
--- a/src/finiteVolume/cfdTools/general/fieldSources/timeActivatedExplicitSource/TimeActivatedExplicitSource.C
+++ b/src/finiteVolume/cfdTools/general/fieldSources/timeActivatedExplicitSource/TimeActivatedExplicitSource.C
@@ -33,7 +33,7 @@ template<class Type>
 const Foam::wordList Foam::TimeActivatedExplicitSource<Type>::
 selectionModeTypeNames_
 (
-    IStringStream("(points cellSet)")()
+    IStringStream("(points cellSet cellZone all)")()
 );
 
 
@@ -156,6 +156,15 @@ void Foam::TimeActivatedExplicitSource<Type>::setSelection
             dict.lookup("cellSet") >> cellSetName_;
             break;
         }
+        case smCellZone:
+        {
+            dict.lookup("cellZone") >> cellSetName_;
+            break;
+        }
+        case smAll:
+        {
+            break;
+        }
         default:
         {
             FatalErrorIn
@@ -221,13 +230,14 @@ void Foam::TimeActivatedExplicitSource<Type>::setCellSet()
         {
             Info<< indent << "- selecting cells using points" << endl;
 
-            labelHashSet cellOwners;
+            labelHashSet selectedCells;
+
             forAll(points_, i)
             {
                 label cellI = mesh_.findCell(points_[i]);
                 if (cellI >= 0)
                 {
-                    cellOwners.insert(cellI);
+                    selectedCells.insert(cellI);
                 }
 
                 label globalCellI = returnReduce(cellI, maxOp<label>());
@@ -239,7 +249,7 @@ void Foam::TimeActivatedExplicitSource<Type>::setCellSet()
                 }
             }
 
-            cellsPtr_.reset(new cellSet(mesh_, "points", cellOwners));
+            cells_ = selectedCells.toc();
 
             break;
         }
@@ -247,7 +257,32 @@ void Foam::TimeActivatedExplicitSource<Type>::setCellSet()
         {
             Info<< indent << "- selecting cells using cellSet "
                 << cellSetName_ << endl;
-            cellsPtr_.reset(new cellSet(mesh_, cellSetName_));
+
+            cellSet selectedCells(mesh_, cellSetName_);
+            cells_ = selectedCells.toc();
+
+            break;
+        }
+        case smCellZone:
+        {
+            Info<< indent << "- selecting cells using cellZone "
+                << cellSetName_ << endl;
+            label zoneID = mesh_.cellZones().findZoneID(cellSetName_);
+            if (zoneID == -1)
+            {
+                FatalErrorIn("TimeActivatedExplicitSource<Type>::setCellIds()")
+                    << "Cannot find cellZone " << cellSetName_ << endl
+                    << "Valid cellZones are " << mesh_.cellZones().names()
+                    << exit(FatalError);
+            }
+            cells_ = mesh_.cellZones()[zoneID];
+
+            break;
+        }
+        case smAll:
+        {
+            Info<< indent << "- selecting all cells" << endl;
+            cells_ = identity(mesh_.nCells());
 
             break;
         }
@@ -261,21 +296,20 @@ void Foam::TimeActivatedExplicitSource<Type>::setCellSet()
         }
     }
 
-    const cellSet& cSet = cellsPtr_();
-
     // Set volume normalisation
-    V_ = scalarField(cSet.size(), 1.0);
     if (volumeMode_ == vmAbsolute)
     {
-        label i = 0;
-        forAllConstIter(cellSet, cSet, iter)
+        V_ = 0.0;
+        forAll(cells_, i)
         {
-            V_[i++] = mesh_.V()[iter.key()];
+            V_ += mesh_.V()[cells_[i]];
         }
+        reduce(V_, sumOp<scalar>());
     }
 
-    Info<< indent << "- selected " << returnReduce(cSet.size(), sumOp<label>())
-        << " cell(s)" << nl << decrIndent << endl;
+    Info<< indent << "- selected "
+        << returnReduce(cells_.size(), sumOp<label>())
+        << " cell(s) with volume " << V_ << nl << decrIndent << endl;
 }
 
 
@@ -299,8 +333,7 @@ Foam::TimeActivatedExplicitSource<Type>::TimeActivatedExplicitSource
     selectionMode_(wordToSelectionModeType(dict.lookup("selectionMode"))),
     points_(),
     cellSetName_("none"),
-    V_(),
-    cellsPtr_(),
+    V_(1.0),
     fieldData_(),
     fieldIds_(fieldNames.size(), -1)
 {
@@ -345,12 +378,9 @@ void Foam::TimeActivatedExplicitSource<Type>::addToField
             setCellSet();
         }
 
-        const cellSet& cSet = cellsPtr_();
-
-        label i = 0;
-        forAllConstIter(cellSet, cSet, iter)
+        forAll(cells_, i)
         {
-            Su[iter.key()] = fieldData_[fid].second()/V_[i++];
+            Su[cells_[i]] = fieldData_[fid].second()/V_;
         }
     }
 }
diff --git a/src/finiteVolume/cfdTools/general/fieldSources/timeActivatedExplicitSource/TimeActivatedExplicitSource.H b/src/finiteVolume/cfdTools/general/fieldSources/timeActivatedExplicitSource/TimeActivatedExplicitSource.H
index 11282a54d3..e014e02cd4 100644
--- a/src/finiteVolume/cfdTools/general/fieldSources/timeActivatedExplicitSource/TimeActivatedExplicitSource.H
+++ b/src/finiteVolume/cfdTools/general/fieldSources/timeActivatedExplicitSource/TimeActivatedExplicitSource.H
@@ -33,7 +33,7 @@ Description
         active          true;      // on/off switch
         timeStart       0.2;       // start time
         duration        2.0;       // duration
-        selectionMode   points;    // cellSet
+        selectionMode   points;    // cellSet/cellZone/all
         volumeMode      absolute;  // specific
 
         fieldData                  // field data - usage for multiple fields
@@ -48,7 +48,8 @@ Description
             (2.75 0.5 0)
         );
 
-        cellSet         c0;        // cellSet name when selectionMode = cekllSet
+        cellSet         c0;        // cellSet name when selectionMode=cellSet
+        cellZone        c0;        // cellZone name when selectionMode=cellZone
     }
 
 SourceFiles
@@ -100,7 +101,9 @@ public:
         enum selectionModeType
         {
             smPoints,
-            smCellSet
+            smCellSet,
+            smCellZone,
+            smAll
         };
 
         //- Word list of selection mode type names
@@ -147,14 +150,14 @@ protected:
         //- List of points for "points" selectionMode
         List<point> points_;
 
-        //- Name of cell set for "cellSet" selectionMode
+        //- Name of cell set for "cellSet" and "cellZone" selectionMode
         word cellSetName_;
 
-        //- Field of cell volumes according to cell set cells
-        scalarList V_;
+        //- Set of cells to apply source to
+        labelList cells_;
 
-        //- Cell set
-        autoPtr<cellSet> cellsPtr_;
+        //- Sum of cell volumes
+        scalar V_;
 
         //- List of source field name vs value pairs
         List<fieldNameValuePair> fieldData_;
@@ -288,12 +291,11 @@ public:
             //  selectionMode
             inline const word& cellSetName() const;
 
-            //- Return const access to the field of cell volumes according to
-            //  cell set cells
-            inline const scalarList& V() const;
+            //- Return const access to the total cell volume
+            inline scalar V() const;
 
             //- Return const access to the cell set
-            inline const cellSet& cells() const;
+            inline const labelList& cells() const;
 
             //- Return const access to the source field name vs value pairs
             inline const List<fieldNameValuePair>& fieldData() const;
@@ -330,12 +332,11 @@ public:
             //  selectionMode
             inline word& cellSetName();
 
-            //- Return access to the field of cell volumes according to
-            //  cell set cells
-            inline scalarList& V();
+            //- Return access to the total cell volume
+            inline scalar& V();
 
             //- Return access to the cell set
-            inline cellSet& cells();
+            inline labelList& cells();
 
             //- Return access to the source field name vs value pairs
             inline List<fieldNameValuePair>& fieldData();
diff --git a/src/finiteVolume/cfdTools/general/fieldSources/timeActivatedExplicitSource/TimeActivatedExplicitSourceI.H b/src/finiteVolume/cfdTools/general/fieldSources/timeActivatedExplicitSource/TimeActivatedExplicitSourceI.H
index be8bd5844a..55a9e7336e 100644
--- a/src/finiteVolume/cfdTools/general/fieldSources/timeActivatedExplicitSource/TimeActivatedExplicitSourceI.H
+++ b/src/finiteVolume/cfdTools/general/fieldSources/timeActivatedExplicitSource/TimeActivatedExplicitSourceI.H
@@ -103,18 +103,17 @@ Foam::TimeActivatedExplicitSource<Type>::cellSetName() const
 
 
 template<class Type>
-inline const Foam::scalarList&
-Foam::TimeActivatedExplicitSource<Type>::V() const
+inline Foam::scalar Foam::TimeActivatedExplicitSource<Type>::V() const
 {
     return V_;
 }
 
 
 template<class Type>
-inline const Foam::cellSet&
+inline const Foam::labelList&
 Foam::TimeActivatedExplicitSource<Type>::cells() const
 {
-    return cellsPtr_();
+    return cells_;
 }
 
 
@@ -195,16 +194,16 @@ inline Foam::word& Foam::TimeActivatedExplicitSource<Type>::cellSetName()
 
 
 template<class Type>
-inline Foam::scalarList& Foam::TimeActivatedExplicitSource<Type>::V()
+inline Foam::scalar& Foam::TimeActivatedExplicitSource<Type>::V()
 {
     return V_;
 }
 
 
 template<class Type>
-inline Foam::cellSet& Foam::TimeActivatedExplicitSource<Type>::cells()
+inline Foam::labelList& Foam::TimeActivatedExplicitSource<Type>::cells()
 {
-    return cellsPtr_();
+    return cells_;
 }