Add "default" construction type to use fixed time constant (tau) from SIA 2024

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

@@ -34,7 +34,8 @@
         {"type": "boolean", "name": "Run obstructed solar simulation?", "nick-name": "RunObstructed?", "description": "Boolean to indicate if an obstructed solar simulation is conducted. True if yes.", "access": "item"},
         {"type": "boolean", "name": "Run hourly?", "nick-name": "RunHourly?", "description": "Boolean to indicate if to run monthly or hourly simulations. True if hourly.", "access": "item"},
         {"type": "boolean", "name": "Use adaptive comfort?", "nick-name": "UseAdaptiveComfort?", "description": "Boolean to indicate if adaptive comfort should be used instead of fixed setpoints. True if yes. Defaults to yes if setpoints_ub and setpoints_lb are null.", "access": "item"},
-        {"type": "boolean", "name": "Use natural ventilation?", "nick-name": "UseNaturalVentilation?", "description": "Boolean to indicate if natural ventilation should be considered (True) or not (False).", "access": "item"}
+        {"type": "boolean", "name": "Use natural ventilation?", "nick-name": "UseNaturalVentilation?", "description": "Boolean to indicate if natural ventilation should be considered (True) or not (False).", "access": "item"},
+        {"type": "boolean", "name": "Use fixed time constant?", "nick-name": "UseFixedTimeConstant?", "description": "Boolean to indicate if the fixed time constant from SIA 2024 should be used (True) or dynamically calculated based on capacities (False).", "access": "item"}
       ],
       "outputs": [
         {"type": "float", "name": "Heating demand", "nick-name": "Q_Heat", "description": "Heating loads of a zone in kWh.", "access": "list"},

src/Hive.Core/sia380/sia380.py

@@ -48,7 +48,8 @@ def cleanDictForNaN(d):
 
 def main(room_properties, room_schedules, floor_area, T_e_hourly, T_i_ub_hourly, T_i_lb_hourly, surface_areas, surface_type,
          srf_irrad_obstr_tree, srf_irrad_unobstr_tree, g_value, g_value_total, setpoint_shading, 
-         run_obstructed_simulation, hourly, use_adaptive_comfort, use_natural_ventilation, debug=False):
+         run_obstructed_simulation, hourly, use_adaptive_comfort, use_natural_ventilation, use_fixed_time_constant,
+         debug=False):
     '''
     Computes monthly heating, cooling and electricity demand for a thermal zone, based on SIA 380.1
     :param room_properties: room properties in json format
@@ -68,6 +69,7 @@ def main(room_properties, room_schedules, floor_area, T_e_hourly, T_i_ub_hourly,
     :param hourly: Boolean to indicate if hourly values should be returned instead of monthly. True if yes.
     :param use_adaptive_comfort: Boolean to indicate if adaptive comfort should be used instead of fixed setpoints. True if yes. Defaults to yes if setpoints_ub and setpoints_lb are null.
     :param use_natural_ventilation: Boolean to indicate if natural ventilation should be considered (True) or not (False).
+    :param use_fixed_time_constant: Boolean to indicate if fixed time constant should be uesd from SIA 2024 (True) or dynamically calculated based on room capacitance (False).
 
     :return: Monthly or hourly cooling, heating and electricity loads for a thermal zone
     '''
@@ -211,7 +213,7 @@ def main(room_properties, room_schedules, floor_area, T_e_hourly, T_i_ub_hourly,
 
     # f_sh = 0.9  # sia2024, p.12, 1.3.1.9 Reduktion solare Wärmeeinträge
     # g = room_properties["Gesamtenergiedurchlassgrad Verglasung"]
-    tau = room_properties["Zeitkonstante"]
+    tau_fixed = room_properties["Zeitkonstante"]
     C_m = room_properties["Waermespeicherfaehigkeit des Raumes"]
     # U_value_opaque = room_properties["U-Wert opake Bauteile"]
     # U_value_transparent = room_properties["U-Wert Fenster"]
@@ -475,11 +477,17 @@ def calculate_step(t,
 
             # time constant of the building (Zeitkonstante), tau
             # TODO where does H_T come from...
-            tau = calc_tau(C_m, floor_area, H_V, H_T) 
-            tau_no_hr = calc_tau(C_m, floor_area, H_V_no_heat_recovery, H_T) 
-            if use_natural_ventilation:
-                tau_heating_nat_vent = calc_tau(C_m, floor_area, H_V_lb_nat_vent, H_T) 
-                tau_cooling_nat_vent = calc_tau(C_m, floor_area, H_V_ub_nat_vent, H_T) 
+            if use_fixed_time_constant:
+                tau = tau_fixed
+                tau_no_hr = tau_fixed
+                tau_heating_nat_vent = tau_fixed
+                tau_cooling_nat_vent = tau_fixed
+            else:
+                tau = calc_tau(C_m, floor_area, H_V, H_T) 
+                tau_no_hr = calc_tau(C_m, floor_area, H_V_no_heat_recovery, H_T) 
+                if use_natural_ventilation:
+                    tau_heating_nat_vent = calc_tau(C_m, floor_area, H_V_lb_nat_vent, H_T) 
+                    tau_cooling_nat_vent = calc_tau(C_m, floor_area, H_V_ub_nat_vent, H_T) 
 
             # for debugging, to compare fixed tau
             # tau = 126.0
@@ -878,10 +886,11 @@ def test():
         results = main(**kwargs)
 
         # Assert
-        Q_Heat, Q_Cool, Q_Elec, Q_T, Q_V, Q_i, Q_s, Q_T_op, Q_T_tr, Q_s_tr_tree = results
+        Q_Heat, Q_dhw, Q_Cool, Q_Elec, Q_T, Q_V, Q_i, Q_s, Q_T_op, Q_T_tr, Q_s_tr_tree = results
         # with open(os.path.join(testdir, "results_variable_tau.json"), 'w') as f:
         #     data = {
         #         "Q_Heat": Q_Heat, 
+        #         "Q_dhw": Q_dhw, 
         #         "Q_Cool": Q_Cool,
         #         "Q_Elec": Q_Elec,
         #         "Q_T": Q_T,
@@ -905,6 +914,7 @@ def test():
         # X = range(t_start, t_end)
         # plt.plot(X, Q_Cool[t_start:t_end], label='Q_Cool')
         # plt.plot(X, Q_Heat[t_start:t_end], label='Q_Heat')
+        # plt.plot(X, Q_dhw[t_start:t_end], label='Q_dhw')
         # plt.plot(X, Q_T[t_start:t_end], ':c', label='Q_T')
         # plt.plot(X, Q_V[t_start:t_end], ':b', label='Q_V')
         # plt.plot(X, Q_i[t_start:t_end], ':g', label='Q_i')

src/Hive.IO/Hive.IO/Building/Sia2024Record.cs

@@ -67,6 +67,7 @@ public Sia2024RecordEx(Sia2024Record room)
 
             RunAdaptiveComfort = room.RunAdaptiveComfort;
             RunNaturalVentilation = room.RunNaturalVentilation;
+            UseFixedTimeConstant = room.UseFixedTimeConstant;
         }
 
         public new static Sia2024RecordEx FromJson(string json)
@@ -122,6 +123,7 @@ public class Sia2024Record
         // custom booleans not part of sia2024
         public bool RunAdaptiveComfort;
         public bool RunNaturalVentilation;
+        public bool UseFixedTimeConstant;
 
         // as per #466, allow Sia2024Record to have separate values for walls, floors, roofs. Fall back to the Opaque values
         private double? _uValueFloors = null;
@@ -262,7 +264,8 @@ public string ToJson()
                 {"Emissionen Waende", EmissionsWalls },
 
                 {"Natuerliche Belueftung", RunNaturalVentilation },
-                {"Adaptiver Komfort", RunAdaptiveComfort }
+                {"Adaptiver Komfort", RunAdaptiveComfort },
+                {"Feste Zeitkonstante", UseFixedTimeConstant }
             };
             return JsonConvert.SerializeObject(result);
         }
@@ -323,7 +326,8 @@ public static Sia2024Record FromJson(string json)
                 _emissionsWalls = readValueOrNull("Emissionen Waende"),
 
                 RunNaturalVentilation = readValueOrFalse("Natuerliche Belueftung"),
-                RunAdaptiveComfort = readValueOrFalse("Adaptiver Komfort")
+                RunAdaptiveComfort = readValueOrFalse("Adaptiver Komfort"),
+                UseFixedTimeConstant = readValueOrFalse("Feste Zeitkonstante")
             };
         }
 

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

@@ -298,6 +298,11 @@ public double RoofsCapacity
         /// </summary>
         [JsonProperty]
         public bool RunNaturalVentilation { get; set; }
+        /// <summary>
+        /// Determines if the fixed time constant provided by SIA2024 should be used.
+        /// </summary>
+        [JsonProperty]
+        public bool UseFixedTimeConstant { get; set; }
 
         #endregion
 

src/Hive.IO/Hive.IO/Building/sia380_constructions.json

@@ -1,4 +1,10 @@
 [
+	{
+		"ConstructionType": "default",
+		"ConstructionTypePretty": "Default",
+		"Description": "Uses the fixed time constants from SIA 2024 instead.",
+		"CapacitancePerFloorArea": 0.0
+	},
 	{
 		"ConstructionType": "superlightweight",
 		"ConstructionTypePretty": "Super Light Weight",

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

@@ -214,11 +214,15 @@ public string Quality
             }
         }
 
+        #region zone properties
+
         public string Construction
         {
-            get => _siaRoom.Construction ?? "undefined";
+            get => _siaRoom.Construction ?? Misc.DefaultConstructionType;
             set
             {
+                _siaRoom.UseFixedTimeConstant = value == Misc.DefaultConstructionType;
+                _zone.UseFixedTimeConstant = value == Misc.DefaultConstructionType;
                 _zone.ApplySia380ConstructionAssembly(value);
                 UpdateSiaRoomConstruction();
 
@@ -227,7 +231,6 @@ public string Construction
             }
         }
 
-        #region zone properties
 
         public bool RunAdaptiveComfort
         {
@@ -263,6 +266,24 @@ public bool RunNaturalVentilation
                 RaisePropertyChangedEvent();
             }
         }
+
+        public bool UseFixedTimeConstant
+        {
+            get => _siaRoom.UseFixedTimeConstant;
+            set
+            {
+                try
+                {
+                    _zone.UseFixedTimeConstant = value;
+                    _siaRoom.UseFixedTimeConstant = value; // not used, only to keep it consistent
+                }
+                catch
+                { }
+
+                RaisePropertyChangedEvent();
+            }
+        }
+
         #endregion
 
         #endregion comboboxes
@@ -288,7 +309,7 @@ public string RoomConstant
 
         public string CapacitancePerFloorArea
         {
-            get => $"{_siaRoom.CapacitancePerFloorArea:0.00}";
+            get => _siaRoom.CapacitancePerFloorArea > 0 ? $"{_siaRoom.CapacitancePerFloorArea:0.00}" : "";
             set
             {
                 try

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

@@ -1,8 +1,5 @@
 using System;
 using System.Collections.Generic;
-using System.Linq;
-using System.Web.Script.Serialization;
-using System.Windows.Documents;
 using Grasshopper.Kernel;
 using Hive.IO.Building;
 
@@ -36,6 +33,7 @@ protected override void RegisterOutputParams(GH_Component.GH_OutputParamManager
             pManager.AddTextParameter("SUA Room Schedules", "SiaRoomSchedules", "Schedules for occupancy, devices, lighting, amd setpoints.", GH_ParamAccess.item);
             pManager.AddBooleanParameter("Use Adaptive Comfort", "UseAdaptiveComfort", "Determines whether to use adaptive comfort (true) or SIA 2024 setpoints (false)", GH_ParamAccess.item);
             pManager.AddBooleanParameter("Use Natural Ventilation", "UseNatVent", "Use natural ventilation in the demand calculation. Based on simplified single sided ventilation", GH_ParamAccess.item);
+            pManager.AddBooleanParameter("Use Fixed Time Constant", "UseFixedTimeConstant", "Use the fixed time constant provided by SIA 2024", GH_ParamAccess.item);
         }
 
 
@@ -113,7 +111,6 @@ protected override void SolveInstance(IGH_DataAccess DA)
             //var json = building.SIA2024.ToJson();
             //JavaScriptSerializer js = new JavaScriptSerializer();
 
-
             DA.SetDataList(0, zoneAreas);
             DA.SetDataList(1, windowAreas);
             DA.SetDataList(2, extSrfAreas);
@@ -123,6 +120,7 @@ protected override void SolveInstance(IGH_DataAccess DA)
             DA.SetData(6, Sia2024Schedules.ToJson(zonesSchedules[0].RoomType)); // single zone !!
             DA.SetData(7, building.Zones[0].RunAdaptiveComfort); // single zone !!
             DA.SetData(8, building.Zones[0].RunNaturalVentilation); // single zone !!
+            DA.SetData(9, building.Zones[0].UseFixedTimeConstant); // single zone !!
         }
 
 

src/Hive.IO/Hive.IO/GhInputOutput/GhBuilding.cs

@@ -248,6 +248,7 @@ private Zone CreateZone(Sia2024Record siaRoom, rg.Brep zoneBrep, List<rg.BrepFac
 
             zone.RunAdaptiveComfort = _buildingInputState.RunAdaptiveComfort;
             zone.RunNaturalVentilation = _buildingInputState.RunNaturalVentilation;
+            zone.UseFixedTimeConstant = _buildingInputState.UseFixedTimeConstant;
 
             return zone;
         }

src/Hive.IO/Hive.IO/Util/Misc.cs

@@ -36,6 +36,8 @@ public static class Misc
 
         public const double Kelvin = 273.15;
 
+        public const string DefaultConstructionType = "default"; // For using fixed tau values instead of variable for SIA 380 demand calc
+
         public static double[] GetAverageMonthlyValue(double[] annualTimeSeries)
         {
             if (annualTimeSeries == null)

tests/Hive.Core/sia380/testdata.json

@@ -2,6 +2,7 @@
     "run_obstructed_simulation": false,
     "use_adaptive_comfort": false,
     "use_natural_ventilation": false,
+    "use_fixed_time_constant": true,
     "hourly": false,
     "g_value": 0.5,
     "g_value_total": 0.14,
@@ -50,6 +51,7 @@
         "Waermeeintragsleistung Personen (bei 24.0 deg C, bzw. 70 W)": 7.0,
         "Waermeeintragsleistung der Raumbeleuchtung": 12.5,
         "Waermeeintragsleistung der Geraete": 10.0,
+        "Jaehrlicher Waermebedarf fuer Warmwasser": 19.8,
         "Vollaststunden pro Jahr (Personen)": 1500.0,
         "Jaehrliche Vollaststunden der Raumbeleuchtung": 1860.0,
         "Jaehrliche Vollaststunden der Geraete": 1930.0,