Add more information for zone terminal unit sizing issue when using ReverseWithLimit in heating dominated climates

src/EnergyPlus/SingleDuct.cc

@@ -3000,7 +3000,46 @@ void SingleDuctAirTerminal::SizeSys(EnergyPlusData &state)
                 }
             }
         }
-
+        if (state.dataSize->TermUnitFinalZoneSizing.size() > 0 && this->DamperHeatingAction == Action::ReverseWithLimits &&
+            TermUnitSizing(state.dataSize->CurTermUnitSizingNum).AirVolFlow <
+                state.dataSize->TermUnitFinalZoneSizing(state.dataSize->CurTermUnitSizingNum).DesHeatVolFlow) {
+            ShowMessage(state, format("SizeHVACSingleDuct: Potential issue with equipment sizing for {} = \"{}\".", this->sysType, this->SysName));
+            ShowContinueError(state,
+                              format("Terminal unit design air flow rate during Reheat of {:.5R} [m3/s] used to size the heating coil",
+                                     TermUnitSizing(state.dataSize->CurTermUnitSizingNum).AirVolFlow));
+            ShowContinueError(state,
+                              format("is less than the zone design heating air flow rate of {:.5R} [m3/s]",
+                                     state.dataSize->TermUnitFinalZoneSizing(state.dataSize->CurTermUnitSizingNum).DesHeatVolFlow));
+            ShowContinueError(
+                state, format("and this {} Maximum Flow Fraction During Reheat is {:.5R} []", this->sysType, this->MaxAirVolFractionDuringReheat));
+            ShowContinueError(state,
+                              format("For reference the zone design cooling air flow rate is {:.5R} [m3/s]",
+                                     state.dataSize->TermUnitFinalZoneSizing(state.dataSize->CurTermUnitSizingNum).DesCoolVolFlow));
+            ShowContinueError(state,
+                              format("For reference the zone design minimum cooling air flow rate is {:.5R} [m3/s]",
+                                     state.dataSize->TermUnitFinalZoneSizing(state.dataSize->CurTermUnitSizingNum).DesCoolVolFlowMin));
+            int zoneNum = state.dataSize->TermUnitFinalZoneSizing(state.dataSize->CurTermUnitSizingNum).ZoneNum;
+            if (zoneNum > 0) {
+                int SizingInputNum =
+                    Util::FindItemInList(state.dataHeatBal->Zone(zoneNum).Name, state.dataSize->ZoneSizingInput, &ZoneSizingInputData::ZoneName);
+                if (SizingInputNum == 0) {
+                    SizingInputNum = 1;
+                }
+                if (state.dataSize->ZoneSizingInput.size() > 0 && state.dataSize->ZoneSizingInput(SizingInputNum).DesHeatMaxAirFlowFrac < 1.0) {
+                    ShowContinueError(state,
+                                      format("Sizing:Zone Heating Maximum Air Flow Fraction = {:.5R}",
+                                             state.dataSize->ZoneSizingInput(SizingInputNum).DesHeatMaxAirFlowFrac));
+                    ShowContinueError(state,
+                                      format("Sizing:Zone Heating Maximum Air Flow per Zone Floor Area = {:.5R} [m3/s/m2]",
+                                             state.dataSize->ZoneSizingInput(SizingInputNum).DesHeatMaxAirFlowPerArea));
+                    ShowContinueError(state, format("For reference the Zone Floor Area = {:.5R} [m3]", state.dataHeatBal->Zone(zoneNum).FloorArea));
+                    ShowContinueError(state,
+                                      format("For reference the zone design maximum heating air flow rate is {:.5R} [m3/s]",
+                                             state.dataSize->TermUnitFinalZoneSizing(state.dataSize->CurTermUnitSizingNum).DesHeatVolFlowMax));
+                }
+            }
+            ShowContinueError(state, "Verify that the values entered are intended and are consistent with other components.");
+        }
         if (TermUnitSizing(state.dataSize->CurTermUnitSizingNum).AirVolFlow > SmallAirVolFlow) {
             if (this->DamperHeatingAction == Action::ReverseWithLimits) {
                 TermUnitSizing(state.dataSize->CurTermUnitSizingNum).ReheatAirFlowMult =