diff --git a/dumux/boxmodels/2pni/2pnifluxvariables.hh b/dumux/boxmodels/2pni/2pnifluxvariables.hh
index a45313b30ff1a135c0247cc81a2868d9dfe21d61..12bce2a7ae7767caddd69453df356d345cc02362 100644
--- a/dumux/boxmodels/2pni/2pnifluxvariables.hh
+++ b/dumux/boxmodels/2pni/2pnifluxvariables.hh
@@ -74,46 +74,46 @@ public:
      *
      * \param problem The problem
      * \param element The finite element
-     * \param elemGeom The finite-volume geometry in the box scheme
+     * \param fvGeometry The finite-volume geometry in the box scheme
      * \param faceIdx The local index of the SCV (sub-control-volume) face
-     * \param elemDat The volume variables of the current element
+     * \param elemVolVars The volume variables of the current element
      * \param onBoundary A boolean variable to specify whether the flux variables
      * are calculated for interior SCV faces or boundary faces, default=false
      */
 
     TwoPNIFluxVariables(const Problem &problem,
                    const Element &element,
-                   const FVElementGeometry &elemGeom,
-                   int scvfIdx,
-                   const ElementVolumeVariables &elemDat,
+                   const FVElementGeometry &fvGeometry,
+                   int faceIdx,
+                   const ElementVolumeVariables &elemVolVars,
                    const bool onBoundary = false)
-        : ParentType(problem, element, elemGeom, scvfIdx, elemDat, onBoundary)
+        : ParentType(problem, element, fvGeometry, faceIdx, elemVolVars, onBoundary)
     {
         // calculate temperature gradient using finite element
         // gradients
         Vector temperatureGrad(0);
-        Vector tmp(0.0);
-        for (int vertIdx = 0; vertIdx < elemGeom.numFAP; vertIdx++)
+        for (int idx = 0; idx < fvGeometry.numFAP; idx++)
         {
-            tmp = this->face().grad[vertIdx];
+            Vector feGrad = this->face().grad[idx];
 
             // index for the element volume variables 
-            int volVarsIdx = this->face().fapIndices[vertIdx];
+            int volVarsIdx = this->face().fapIndices[idx];
             
-            tmp *= elemDat[volVarsIdx].temperature();
-            temperatureGrad += tmp;
+            feGrad *= elemVolVars[volVarsIdx].temperature();
+            temperatureGrad += feGrad;
         }
 
         // The spatial parameters calculates the actual heat flux vector
-        problem.spatialParameters().matrixHeatFlux(tmp,
+        Vector heatFlux;
+        problem.spatialParams().matrixHeatFlux(heatFlux,
                                                    *this,
-                                                   elemDat,
+                                                   elemVolVars,
                                                    temperatureGrad,
                                                    element,
-                                                   elemGeom,
-                                                   scvfIdx);
+                                                   fvGeometry,
+                                                   faceIdx);
         // project the heat flux vector on the face's normal vector
-        normalMatrixHeatFlux_ = tmp * this->face().normal;
+        normalMatrixHeatFlux_ = heatFlux * this->face().normal;
     }
 
     /*!
diff --git a/dumux/boxmodels/2pni/2pnilocalresidual.hh b/dumux/boxmodels/2pni/2pnilocalresidual.hh
index 357b26c90daf8830949ac19b56bc51fe1962d926..8a69b44ad77afe284bc787c6126d578f0dfc0d39 100644
--- a/dumux/boxmodels/2pni/2pnilocalresidual.hh
+++ b/dumux/boxmodels/2pni/2pnilocalresidual.hh
@@ -91,33 +91,33 @@ public:
      * The result should be averaged over the volume (e.g. phase mass
      * inside a sub control volume divided by the volume)
      *
-     *  \param result The phase mass within the sub-control volume
+     *  \param storage The phase mass within the sub-control volume
      *  \param scvIdx The SCV (sub-control-volume) index
      *  \param usePrevSol Evaluate function with solution of current or previous time step
      */
-    void computeStorage(PrimaryVariables &result, int scvIdx, bool usePrevSol) const
+    void computeStorage(PrimaryVariables &storage, int scvIdx, bool usePrevSol) const
     {
         // compute the storage term for phase mass
-        ParentType::computeStorage(result, scvIdx, usePrevSol);
+        ParentType::computeStorage(storage, scvIdx, usePrevSol);
 
         // if flag usePrevSol is set, the solution from the previous
         // time step is used, otherwise the current solution is
         // used. The secondary variables are used accordingly.  This
         // is required to compute the derivative of the storage term
         // using the implicit euler method.
-        const ElementVolumeVariables &vertDatArray = usePrevSol ? this->prevVolVars_() : this->curVolVars_();
-        const VolumeVariables &vertDat = vertDatArray[scvIdx];
+        const ElementVolumeVariables &elemVolVars = usePrevSol ? this->prevVolVars_() : this->curVolVars_();
+        const VolumeVariables &volVars = elemVolVars[scvIdx];
 
         // compute the energy storage
-        result[temperatureIdx] =
-            vertDat.porosity()*(vertDat.density(wPhaseIdx) *
-                                vertDat.internalEnergy(wPhaseIdx) *
-                                vertDat.saturation(wPhaseIdx)
+        storage[temperatureIdx] =
+            volVars.porosity()*(volVars.density(wPhaseIdx) *
+                                volVars.internalEnergy(wPhaseIdx) *
+                                volVars.saturation(wPhaseIdx)
                                 +
-                                vertDat.density(nPhaseIdx) *
-                                vertDat.internalEnergy(nPhaseIdx) *
-                                vertDat.saturation(nPhaseIdx))
-          + vertDat.temperature()*vertDat.heatCapacity();
+                                volVars.density(nPhaseIdx) *
+                                volVars.internalEnergy(nPhaseIdx) *
+                                volVars.saturation(nPhaseIdx))
+          + volVars.temperature()*volVars.heatCapacity();
     }
 
     /*!
@@ -139,13 +139,13 @@ public:
 
         // advective heat flux in all phases
         flux[energyEqIdx] = 0;
-        Vector tmpVec;
+        Vector kGradPotential;
         for (int phaseIdx = 0; phaseIdx < numPhases; ++phaseIdx) {
             // calculate the flux in the normal direction of the
             // current sub control volume face
             fluxVars.intrinsicPermeability().mv(fluxVars.potentialGrad(phaseIdx),
-                                                tmpVec);
-            Scalar normalFlux = -(tmpVec*fluxVars.face().normal);
+                                                kGradPotential);
+            Scalar normalFlux = -(kGradPotential*fluxVars.face().normal);
 
             // data attached to upstream and the downstream vertices
             // of the current phase
@@ -173,17 +173,17 @@ public:
      *        the face of a sub-control volume.
      *
      * \param flux The diffusive flux over the sub-control-volume face for each phase
-     * \param fluxData The flux variables at the current SCV
+     * \param fluxVars The flux variables at the current SCV
      *
      */
     void computeDiffusiveFlux(PrimaryVariables &flux,
-                              const FluxVariables &fluxData) const
+                              const FluxVariables &fluxVars) const
     {
         // diffusive mass flux
-        ParentType::computeDiffusiveFlux(flux, fluxData);
+        ParentType::computeDiffusiveFlux(flux, fluxVars);
 
         // diffusive heat flux
-        flux[energyEqIdx] += fluxData.normalMatrixHeatFlux();
+        flux[energyEqIdx] += fluxVars.normalMatrixHeatFlux();
     }
 
 private:
diff --git a/dumux/boxmodels/2pni/2pnivolumevariables.hh b/dumux/boxmodels/2pni/2pnivolumevariables.hh
index 07bb165f3c4d1aaf9d530e1bc1f74774ef57a6ab..a27f80cc5567f61aa7eef9a2e18d9daff5e15479 100644
--- a/dumux/boxmodels/2pni/2pnivolumevariables.hh
+++ b/dumux/boxmodels/2pni/2pnivolumevariables.hh
@@ -90,7 +90,7 @@ protected:
     static Scalar temperature_(const PrimaryVariables &priVars,
                             const Problem& problem,
                             const Element &element,
-                            const FVElementGeometry &elemGeom,
+                            const FVElementGeometry &fvGeometry,
                             int scvIdx)
     {
         return priVars[Indices::temperatureIdx];
@@ -107,15 +107,15 @@ protected:
     /*!
      * \brief Called by update() to compute the energy related quantities
      */
-    void updateEnergy_(const PrimaryVariables &sol,
+    void updateEnergy_(const PrimaryVariables &priVars,
                        const Problem &problem,
                        const Element &element,
-                       const FVElementGeometry &elemGeom,
+                       const FVElementGeometry &fvGeometry,
                        int scvIdx,
                        bool isOldSol)
     {
         // copmute and set the heat capacity of the solid phase
-        heatCapacity_ = problem.spatialParameters().heatCapacity(element, elemGeom, scvIdx);
+        heatCapacity_ = problem.spatialParams().heatCapacity(element, fvGeometry, scvIdx);
         Valgrind::CheckDefined(heatCapacity_);
     }