Add unmet water heater loads EMS program

BuildResidentialScheduleFile/README.md

@@ -24,7 +24,7 @@ Absolute/relative path of the HPXML file.
 
 **Schedules: Column Names**
 
-A comma-separated list of the column names to generate. If not provided, defaults to all columns. Possible column names are: occupants, lighting_interior, lighting_garage, cooking_range, dishwasher, clothes_washer, clothes_dryer, ceiling_fan, plug_loads_other, plug_loads_tv, hot_water_dishwasher, hot_water_clothes_washer, hot_water_fixtures.
+A comma-separated list of the column names to generate. If not provided, defaults to all columns. Possible column names are: occupants, lighting_interior, lighting_garage, cooking_range, dishwasher, clothes_washer, clothes_dryer, ceiling_fan, plug_loads_other, plug_loads_tv, hot_water_dishwasher, hot_water_clothes_washer, hot_water_fixtures, hot_water_showers.
 
 - **Name:** ``schedules_column_names``
 - **Type:** ``String``

BuildResidentialScheduleFile/resources/schedules.rb

@@ -514,6 +514,7 @@ def create_stochastic_schedules(args:,
     shower_activity_sch = aggregate_array(shower_activity_sch, @minutes_per_step)
     shower_peak_flow = shower_activity_sch.max
     showers = shower_activity_sch.map { |flow| flow / shower_peak_flow }
+    @schedules[SchedulesFile::ColumnHotWaterShowers] = showers
 
     random_offset = (prng.rand * 2 * offset_range).to_i - offset_range
     sink_activity_sch = sink_activity_sch.rotate(-4 * 60 + random_offset) # 4 am shifting

Changelog.md

@@ -117,6 +117,7 @@ __New Features__
 - Allows above-grade basements/crawlspaces defined solely with Wall (not FoundationWall) elements.
 - Updates to 2022 EIA energy costs.
 - Added README.md documentation for all OpenStudio measures.
+- Added metrics for unmet hot water loads
 
 __Bugfixes__
 - Fixes battery resilience output to properly incorporate battery losses.

HPXMLtoOpenStudio/measure.rb

@@ -1533,18 +1533,22 @@ def add_hot_water_and_appliances(runner, model, weather, spaces)
     end
 
     # Hot water fixtures and appliances
-    HotWaterAndAppliances.apply(model, runner, @hpxml_header, @hpxml_bldg, weather, spaces, hot_water_distribution,
-                                solar_thermal_system, @eri_version, @schedules_file, plantloop_map,
-                                @hpxml_header.unavailable_periods, @hpxml_bldg.building_construction.number_of_units,
+    showers_peak_flows = HotWaterAndAppliances.apply(model, runner, @hpxml_header, @hpxml_bldg, weather, spaces, hot_water_distribution,
+                                                     solar_thermal_system, @eri_version, @schedules_file, plantloop_map,
+                                                     @hpxml_header.unavailable_periods, @hpxml_bldg.building_construction.number_of_units,
                                 @apply_ashrae140_assumptions)
 
+
     if (not solar_thermal_system.nil?) && (not solar_thermal_system.collector_area.nil?) # Detailed solar water heater
       loc_space, loc_schedule = get_space_or_schedule_from_location(solar_thermal_system.water_heating_system.location, model, spaces)
       Waterheater.apply_solar_thermal(model, loc_space, loc_schedule, solar_thermal_system, plantloop_map, unit_multiplier)
     end
 
     # Add combi-system EMS program with water use equipment information
     Waterheater.apply_combi_system_EMS(model, @hpxml_bldg.water_heating_systems, plantloop_map)
+
+    # Add unmet wh loads calculation
+    Waterheater.unmet_wh_loads_program(model, @hpxml_bldg.water_heating_systems, plantloop_map, showers_peak_flows)
   end
 
   def add_cooling_system(model, runner, weather, spaces, airloop_map)

HPXMLtoOpenStudio/resources/constants.rb

@@ -348,6 +348,10 @@ def self.ObjectNameRoomAirConditioner
     return 'room ac'
   end
 
+  def self.ObjectNameShowers
+    return 'hot_water_showers'
+  end
+
   def self.ObjectNameSolarHotWater
     return 'solar hot water'
   end
@@ -364,6 +368,10 @@ def self.ObjectNameUnmetHoursProgram
     return 'unmet hours program'
   end
 
+  def self.ObjectNameUnmetLoadsProgram
+    return 'unmet loads program'
+  end
+
   def self.ObjectNameWaterHeater
     return 'water heater'
   end

HPXMLtoOpenStudio/resources/data/unavailable_periods.csv

@@ -24,6 +24,7 @@ pool_heater,0,1
 permanent_spa_pump,0,1
 permanent_spa_heater,0,1
 hot_water_fixtures,1,1
+hot_water_showers,1,1
 hot_water_recirculation_pump,1,1
 general_water_use,1,0
 hvac,0,1

HPXMLtoOpenStudio/resources/hotwater_appliances.rb

@@ -327,27 +327,56 @@ def self.apply(model, runner, hpxml_header, hpxml_bldg, weather, spaces, hot_wat
         runner.registerWarning("Both '#{fixtures_col_name}' schedule file and weekend fractions provided; the latter will be ignored.") if !hpxml_bldg.water_heating.water_fixtures_weekend_fractions.nil?
         runner.registerWarning("Both '#{fixtures_col_name}' schedule file and monthly multipliers provided; the latter will be ignored.") if !hpxml_bldg.water_heating.water_fixtures_monthly_multipliers.nil?
       end
+
+      # Create shower schedule, used only for unmet load calculations
+      # Create separate shower schedule: Only used for calculating unmet loads. Shower hot water usage is part of the fixtures usage.
+      showers_schedule = nil
+      showers_col_name = SchedulesFile::Columns[:HotWaterShowers].name
+      if not schedules_file.nil?
+        showers_schedule = schedules_file.create_schedule_file(model, col_name: showers_col_name, schedule_type_limits_name: Constants.ScheduleTypeLimitsFraction)
+      end
+      if showers_schedule.nil?
+        showers_unavailable_periods = Schedule.get_unavailable_periods(runner, showers_col_name, unavailable_periods)
+        showers_weekday_sch = Schedule.ShowersWeekdayFractions # FIXME: should we expose HPXML elements for these? sounds like maybe not.
+        showers_weekend_sch = Schedule.ShowersWeekendFractions
+        showers_monthly_sch = Schedule.ShowersMonthlyMultipliers
+        showers_schedule_obj = MonthWeekdayWeekendSchedule.new(model, Constants.ObjectNameShowers, showers_weekday_sch, showers_weekend_sch, showers_monthly_sch, Constants.ScheduleTypeLimitsFraction, unavailable_periods: showers_unavailable_periods)
+      else
+        runner.registerWarning("Both '#{showers_col_name}' schedule file and weekday fractions provided; the latter will be ignored.") if !Schedule.ShowersWeekdayFractions.nil?
+        runner.registerWarning("Both '#{showers_col_name}' schedule file and weekend fractions provided; the latter will be ignored.") if !Schedule.ShowersWeekendFractions.nil?
+        runner.registerWarning("Both '#{showers_col_name}' schedule file and monthly multipliers provided; the latter will be ignored.") if !Schedule.ShowersMonthlyMultipliers.nil?
+      end
     end
 
+    # create an array of peak flow to return
+    shower_peak_flows = {} # used for unmet wh load calculations
     hpxml_bldg.water_heating_systems.each do |water_heating_system|
       non_solar_fraction = 1.0 - Waterheater.get_water_heater_solar_fraction(water_heating_system, solar_thermal_system)
 
       gpd_frac = water_heating_system.fraction_dhw_load_served # Fixtures fraction
       if gpd_frac > 0
 
+        # For showers, calculate flow rates but don't add a WaterUse:Equipment object. Shower usage is included in fixtures and only used for tracking unmet loads
         fx_gpd = get_fixtures_gpd(eri_version, nbeds, frac_low_flow_fixtures, daily_mw_fractions, fixtures_usage_multiplier)
+        shower_gpd = get_showers_gpd(eri_version, nbeds, frac_low_flow_fixtures, daily_mw_fractions, fixtures_usage_multiplier)
         w_gpd = get_dist_waste_gpd(eri_version, nbeds, has_uncond_bsmnt, has_cond_bsmnt, cfa, ncfl, hot_water_distribution, frac_low_flow_fixtures, fixtures_usage_multiplier)
 
         fx_peak_flow = nil
+        shower_peak_flow = nil
         if not schedules_file.nil?
           fx_peak_flow = schedules_file.calc_peak_flow_from_daily_gpm(col_name: SchedulesFile::Columns[:HotWaterFixtures].name, daily_water: fx_gpd)
+          shower_peak_flow = schedules_file.calc_peak_flow_from_daily_gpm(col_name: SchedulesFile::Columns[:HotWaterShowers].name, daily_water: shower_gpd)
           dist_water_peak_flow = schedules_file.calc_peak_flow_from_daily_gpm(col_name: SchedulesFile::Columns[:HotWaterFixtures].name, daily_water: w_gpd)
         end
         if fx_peak_flow.nil?
           fx_peak_flow = fixtures_schedule_obj.calc_design_level_from_daily_gpm(fx_gpd)
+          shower_peak_flow = showers_schedule_obj.calc_design_level_from_daily_gpm(shower_gpd)
           dist_water_peak_flow = fixtures_schedule_obj.calc_design_level_from_daily_gpm(w_gpd)
         end
 
+        id = water_heating_system.id
+        shower_peak_flows[id] = shower_peak_flow * gpd_frac * non_solar_fraction
+
         # Fixtures (showers, sinks, baths)
         add_water_use_equipment(model, fixtures_obj_name, fx_peak_flow * gpd_frac * non_solar_fraction, fixtures_schedule, water_use_connections[water_heating_system.id], unit_multiplier, mw_temp_schedule)
 
@@ -470,6 +499,8 @@ def self.apply(model, runner, hpxml_header, hpxml_bldg, weather, spaces, hot_wat
       add_other_equipment(model, Constants.ObjectNameGeneralWaterUseSensible, conditioned_space, water_design_level_sens, 1.0, 0.0, water_schedule, nil)
       add_other_equipment(model, Constants.ObjectNameGeneralWaterUseLatent, conditioned_space, water_design_level_lat, 0.0, 1.0, water_schedule, nil)
     end
+
+    return shower_peak_flows
   end
 
   def self.get_range_oven_default_values()
@@ -1088,6 +1119,27 @@ def self.get_fixtures_gpd(eri_version, nbeds, frac_low_flow_fixtures, daily_mw_f
     return f_eff * ref_f_gpd * fixtures_usage_multiplier
   end
 
+  def self.get_showers_gpd(eri_version, nbeds, frac_low_flow_fixtures, daily_mw_fractions, fixtures_usage_multiplier = 1.0)
+    if nbeds < 0.0
+      return 0.0
+    end
+
+    if Constants.ERIVersions.index(eri_version) < Constants.ERIVersions.index('2014A')
+      # Note that the standard only has a total hot water usage, it does not specify a fraction for showers. Assuming showers are 40% of total HW usage (based on BA Benchmark usage)
+      showers_gpd = 0.4 * (30.0 + 10.0 * nbeds) # Table 4.2.2(1) Service water heating systems
+      # Convert to mixed water gpd
+      avg_mw_fraction = daily_mw_fractions.reduce(:+) / daily_mw_fractions.size.to_f
+      return showers_gpd / avg_mw_fraction * fixtures_usage_multiplier
+    end
+
+    # ANSI/RESNET 301-2014 Addendum A-2015
+    # Amendment on Domestic Hot Water (DHW) Systems
+    ref_shower_gpd = 14.0 + 4.67 * nbeds # Based on BA Benchmark shower usage
+    f_eff = get_fixtures_effectiveness(frac_low_flow_fixtures)
+
+    return f_eff * ref_shower_gpd * fixtures_usage_multiplier
+  end
+
   def self.get_water_gains_sens_lat(nbeds, general_water_use_usage_multiplier = 1.0)
     # Table 4.2.2(3). Internal Gains for Reference Homes
     sens_gains = (-1227.0 - 409.0 * nbeds) * general_water_use_usage_multiplier # Btu/day

HPXMLtoOpenStudio/resources/output.rb

@@ -108,6 +108,12 @@ class UHT
   Cooling = 'Cooling'
 end
 
+class ULT
+  # Unmet Loads Types
+  HotWaterShowerE = 'Hot Water Shower Energy'
+  HotWaterShowerUnmetTime = 'Hot Water Shower Unmet Time'
+end
+
 class RT
   # Resilience Types
   Battery = 'Battery'