Extended HI followup: fix speed issue

doc/engineering-reference/src/special-modules-reporting/resilience-metrics.tex

@@ -66,7 +66,7 @@ \subsubsection{Heat Index}\label{heat-index}
 \end{tabular}
 \end{table}
 
-The computation of the heat index is a refinement of a result obtained by
+Before version 25.1, the computation of the heat index is a refinement of a result obtained by
 multiple regression analysis carried out by Lans P. Rothfusz and described in a
 1990 National Weather Service (NWS) Technical Attachment (SR 90-23) [4-5]. The
 calculation is based on degree Fahrenheit.
@@ -130,6 +130,17 @@ \subsubsection{Heat Index}\label{heat-index}
 regression is not valid for extreme temperature and relative humidity conditions
 beyond the range of data considered by Steadman.
 
+Starting from version 25.1, the heat index calculation allows the use of the extended heat
+index method developed by Lu \& Romps [17]. By selecting ``Extended'' in the ``Algorithm''
+field of HeatIndexAlgorithm, this extended heat index will be used. If the field is
+``Simplified'' or left empty, the Rothfusz-Steadman method described above will be used.
+The heat index calculated with Rothfusz-Steadman method can give
+unrealistic results for very hot and humid or very cold and dry conditions. The
+extended index extends the domain of the heat index calculation to all
+combinations of temperature and relative humidity and gives a more realistic heat
+index for the extreme conditions. The implementation in EnergyPlus is based on
+the released Python code by Lu and Romps [18].
+
 The Heat Index Hours (accumulated hours for a space) and Heat Index
 OccupantHours (accumulated hours for the sum of all occupants in a space) of
 each level for each zone and the whole building are reported under the Annual
@@ -516,3 +527,11 @@ \subsection{References}
 
 {[}16{]} ACGIH, Threshold Limit Values (TLVs) and Biological Exposure Indices
 (BEIs), 2012. doi:10.1073/pnas.0703993104.
+
+{[}17{]} Lu, Yi-Chuan, and David M. Romps. ``Extending the heat index''. Journal
+of Applied Meteorology and Climatology 61, no. 10 (2022): 1367-1383.
+doi:10.1073/pnas.0703993104.
+
+{[}18{]} Lu, Yi-Chuan, and David M. Romps. ``Lu and Romps, Extending the heat index, JAMC, 2022'',
+Physics of Climate, February 23, 2023.
+https://romps.berkeley.edu/papers/pubs-2020-heatindex.html.

doc/input-output-reference/src/input-for-output.tex

@@ -346,6 +346,21 @@
 OutputControl:ReportingTolerances,.21,.21;
 \end{lstlisting}
 
+\subsection{OutputControl:ResilienceSummaries}\label{OutputControlResilienceSummaries}
+
+This input specifies methods or algorithms used in certain resilience reporting variables.
+
+\subsubsection{Inputs}\label{inputs-8-020}
+
+\paragraph{Field: Heat Index Algorithm}\label{Heat-Index-Algorithm}
+
+This field has two choices: \textbf{Simplified} and \textbf{Extended}. The
+Simplified option is the default and by choosing this, the heat index will be
+calculated using the method based on regression analysis carried out by Lans P.
+Rothfusz. When Extended is selected, the heat index will be computed using the
+extended heat index method developed by Lu \& Romps. Note that using the
+Extended method is slower to simulate.
+
 \subsection{Output:Variable}\label{outputvariable}
 
 This input object is used request results reporting.~ As shown above in the Variable Dictionary Report section, there are many different output variables available for reporting results from EnergyPlus.~ The Output:Variable object is primarily used for reporting time series data at various frequencies.

idd/Energy+.idd.in

@@ -107028,6 +107028,18 @@ OutputControl:ReportingTolerances,
        \minimum 0
        \maximum 10
 
+OutputControl:ResilienceSummaries,
+       \memo Specifies methods for resilience reporting variables
+       \unique-object
+  A1 ; \field Heat Index Algorithm
+       \note Whether the simplified or the extended method should be used for heat index
+       \note Simplified: based on regression analysis carried out by Lans P. Rothfusz
+       \note Extended: Based on paper by Lu & Romps
+       \type choice
+       \key Simplified
+       \key Extended
+       \default Simplified
+
 Output:Variable,
        \memo each Output:Variable command picks variables to be put onto the standard output file (.eso)
        \memo some variables may not be reported for every simulation.

src/EnergyPlus/CMakeLists.txt

@@ -265,6 +265,8 @@ set(SRC
     EvaporativeFluidCoolers.hh
     ExhaustAirSystemManager.cc
     ExhaustAirSystemManager.hh
+    ExtendedHeatIndex.cc
+    ExtendedHeatIndex.hh
     ExteriorEnergyUse.cc
     ExteriorEnergyUse.hh
     ExternalInterface.cc

src/EnergyPlus/DataHeatBalance.hh

@@ -547,6 +547,19 @@ namespace DataHeatBalance {
         {
         }
     };
+
+    enum class HeatIndexMethod : int
+    {
+        Invalid = -1,
+        Simplified,
+        Extended,
+        Num
+    };
+    static constexpr std::array<std::string_view, static_cast<int>(HeatIndexMethod::Num)> HeatIndexMethodUC = {
+        "SIMPLIFIED",
+        "EXTENDED",
+    };
+
     struct ZoneData : ZoneSpaceData
     {
         // Members
@@ -1849,6 +1862,7 @@ struct HeatBalanceData : BaseGlobalStruct
     bool NoRegularMaterialsUsed = true;
     bool DoLatentSizing = false; // true when latent sizing is performed during zone sizing
     bool isAnyLatentLoad = false;
+    DataHeatBalance::HeatIndexMethod heatIndexMethod = DataHeatBalance::HeatIndexMethod::Simplified;
 
     Array1D<Real64> ZoneListSNLoadHeatEnergy;
     Array1D<Real64> ZoneListSNLoadCoolEnergy;