reducing net floor area for loads calculations

src/Hive.Core/sia380/Hive.Core.sia380.json

@@ -38,6 +38,7 @@
       ],
       "outputs": [
         {"type": "float", "name": "Heating demand", "nick-name": "Q_Heat", "description": "Heating loads of a zone in kWh.", "access": "list"},
+        {"type": "float", "name": "Domestic hot water demand", "nick-name": "Q_dhw", "description": "Domestic hot water demands of a zone in kWh.", "access": "list"},
         {"type": "float", "name": "Cooling demand", "nick-name": "Q_Cool", "description": "Cooling loads of a zone in kWh.", "access": "list"},
         {"type": "float", "name": "Electricity demand", "nick-name": "Q_Elec", "description": "Electricity loads of a zone in kWh.", "access": "list"},
         {"type": "float", "name": "Transmission heat losses", "nick-name": "Q_T", "description": "Transmission heat losses of a zone in kWh.", "access": "list"},

src/Hive.IO/Hive.IO/Building/Zone.cs

@@ -111,7 +111,8 @@ public struct StructInternalLoads
         public double WallsArea => Walls.Sum(w => w.Area);
         public double RoofsArea => Roofs.Sum(r => r.Area);
         public double WindowArea => Windows.Sum(w => w.Area);
-        public double FloorsArea => Floors.Sum(f => f.Area);
+        public double FloorsAreaNet => Floors.Sum(f => f.Area) * 0.9; // SIA 2024 E.3
+        public double FloorsAreaGross => Floors.Sum(f => f.Area); 
 
         #endregion
 
@@ -148,7 +149,7 @@ public void ApplySia380ConstructionAssembly(string siaConstructionType)
             for (int i = 0; i < Windows.Length; i++) Windows[i].Construction = siaConstruction.WindowsConstruction;
 
             // Update the capacitances of the components
-            siaConstruction.SetCapacities(FloorsArea, WallsArea, RoofsArea);
+            siaConstruction.SetCapacities(FloorsAreaNet, WallsArea, RoofsArea);
             CapacitancePerFloorArea = siaConstruction.CapacitancePerFloorArea;
         }
 
@@ -179,9 +180,9 @@ public double CapacitancePerFloorArea
         void UpdateCapacities()
         {
             // Recalculate in case surface areas have changed
-            var factorAll = 1 + RoofsArea / FloorsArea + WallsArea / FloorsArea;
+            var factorAll = 1 + RoofsArea / FloorsAreaNet + WallsArea / FloorsAreaNet;
             // Assign capacities per component type. To use in sia380 GH component (demand calculation).
-            FloorsCapacity = FloorsArea / factorAll * CapacitancePerFloorArea;
+            FloorsCapacity = FloorsAreaNet / factorAll * CapacitancePerFloorArea;
             RoofsCapacity = RoofsArea / factorAll * CapacitancePerFloorArea;
             WallsCapacity = WallsArea / factorAll * CapacitancePerFloorArea;
         }
@@ -212,7 +213,7 @@ public double FloorsCapacity
             {
                 foreach (Floor floor in Floors)
                 {
-                    floor.Construction.Capacitance = value * (floor.Area / FloorsArea);
+                    floor.Construction.Capacitance = value * (floor.Area / FloorsAreaNet);
                 }
                 _floorsCapacitance = value;
             }

src/Hive.IO/Hive.IO/Forms/BuildingInputForm.cs

@@ -44,6 +44,9 @@ private void BuildingInputForm_Load(object sender, EventArgs e)
             hizardToolTip.SetToolTip(this.txtCoolingSetback, toolTipSetbackInfoMessage);
             hizardToolTip.SetToolTip(this.label41, toolTipSetbackInfoMessage);
 
+            hizardToolTip.SetToolTip(this.txtFloorArea, toolTipFloorArea);
+            hizardToolTip.SetToolTip(this.label7, toolTipFloorArea);
+
             RenderState();
         }
 
@@ -376,6 +379,10 @@ private void checkBoxNaturalVentilation_CheckedChanged(object sender, EventArgs
 
         private const string toolTipSetbackInfoMessage = "Only used during hourly demand calculation, which is currently WIP";
 
+        private const string toolTipFloorArea =
+            "Note that this number refers to the gross area (Energiebezugsflaeche) measured from the hull geometry." + "\n " +
+            "For loads calculation, this area will be reduced by 0.9, according to SIA 2024, E.3";
+
         private void textBoxSetback_MouseHover(object sender, EventArgs e)
         {
             hizardToolTip.Show(toolTipSetbackInfoMessage, (TextBox)sender);

src/Hive.IO/Hive.IO/Forms/BuildingInputState.cs

@@ -160,7 +160,7 @@ public void UpdateSiaRoomConstruction()
         // it works like this: (x?.a) is x.a if x != null, else null. (A ?? B) is A if A != null, else B
         // I'm using this to enable creating a BuildingInputSate with zone == null for testing purposes.
         public string ZoneWallArea => $"{_zone?.WallsArea ?? _siaRoom.EnvelopeArea:0.00}";
-        public string ZoneFloorArea => $"{_zone?.FloorsArea ?? _siaRoom.FloorArea:0.00}";
+        public string ZoneFloorArea => $"{_zone?.FloorsAreaGross ?? _siaRoom.FloorArea:0.00}";
         public string ZoneRoofArea => $"{_zone?.RoofsArea ?? _siaRoom.EnvelopeArea:0.00}";
         public string ZoneWindowArea => $"{_zone?.WindowArea ?? _siaRoom.EnvelopeArea:0.00}";
 

src/Hive.IO/Hive.IO/GhDistributors/GhDistSIA.cs

@@ -27,7 +27,7 @@ protected override void RegisterInputParams(GH_Component.GH_InputParamManager pM
 
         protected override void RegisterOutputParams(GH_Component.GH_OutputParamManager pManager)
         {
-            pManager.AddNumberParameter("Zone Areas", "ZoneAreas", "Floor areas in [m²] of all zones of the building.", GH_ParamAccess.list);
+            pManager.AddNumberParameter("Net Zone Areas", "ZoneAreas", "Net Floor areas in [m²] of all zones of the building.", GH_ParamAccess.list);
             pManager.AddNumberParameter("Windows Areas", "WinAreas", "All window areas in [m²] of the building.", GH_ParamAccess.list);
             pManager.AddNumberParameter("External Surfaces Areas", "ExtSrfAreas", "Surface areas of the building that are exposed to the environment (external)", GH_ParamAccess.list);
             pManager.AddTextParameter("SIA 2024 Room", "SiaRoom", "SIA 2024 room definitions for each zone.", GH_ParamAccess.item);
@@ -56,11 +56,10 @@ protected override void SolveInstance(IGH_DataAccess DA)
             {
                 Zone zone = building.Zones[i];
 
-                zoneAreas[i] = 0.0;
+                zoneAreas[i] = zone.FloorsAreaNet;
                 foreach (Floor floor in zone.Floors)
                 {
                     // TO DO: make check that it's not a void
-                    zoneAreas[i] += floor.Area;
                     if (floor.IsExternal)
                     {
                         extSrfAreas.Add(floor.Area);