Building Energy Standards Water Heater Data Update

data/standards/manage_OpenStudio_Standards.rb

@@ -117,7 +117,7 @@ def unique_properties(sheet_name)
          when 'unitary_acs'
            ['template', 'cooling_type', 'heating_type', 'subcategory', 'minimum_capacity', 'maximum_capacity', 'start_date', 'end_date']
          when 'water_heaters'
-           ['template', 'fuel_type', 'minimum_capacity', 'maximum_capacity', 'start_date', 'end_date']
+           ['template', 'equipment_type', 'fuel_type', 'minimum_capacity', 'maximum_capacity', 'minimum_storage', 'maximum_storage', 'minimum_capacity_per_storage', 'maximum_capacity_per_storage', 'draw_profile', 'start_date', 'end_date']
          when 'elevators'
            ['template', 'building_type']
          when 'refrigeration_system_lineup', 'refrigeration_system'

lib/openstudio-standards.rb

@@ -347,6 +347,7 @@ module OpenstudioStandards
   require_relative "#{stds}/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.FanVariableVolume"
   require_relative "#{stds}/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.Space"
   require_relative "#{stds}/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.ThermalZone"
+  require_relative "#{stds}/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.WaterHeaterMixed"
   # 90.1-PRM Common
   require_relative "#{stds}/ashrae_90_1_prm/ashrae_90_1_prm"
   require_relative "#{stds}/ashrae_90_1_prm/ashrae_90_1_prm.Model"

lib/openstudio-standards/prototypes/common/objects/Prototype.hvac_systems.rb

@@ -612,7 +612,6 @@ def model_add_cw_loop(model,
         next unless dd.dayType == 'SummerDesignDay'
         next unless dd.name.get.to_s.include?('WB=>MDB')
 
-
         if condenser_water_loop.model.version < OpenStudio::VersionString.new('3.3.0')
           if dd.humidityIndicatingType == 'Wetbulb'
             summer_oat_wb_c = dd.humidityIndicatingConditionsAtMaximumDryBulb

lib/openstudio-standards/standards/Standards.Model.rb

@@ -2362,14 +2362,17 @@ def model_apply_infiltration_standard(model)
   #   the objects will only be returned if the specified area is between the minimum_area and maximum_area values.
   # @param num_floors [Double] capacity of the object in question.  If num_floors is supplied,
   #   the objects will only be returned if the specified num_floors is between the minimum_floors and maximum_floors values.
+  # @param fan_motor_hp [Double] fan motor brake horsepower.
+  # @param volume [Double] Equipment storage capacity in gallons.
+  # @param capacity_per_volume [Double] Equipment capacity per storage capacity in Btu/h/gal.
   # @return [Array] returns an array of hashes, one hash per object.  Array is empty if no results.
   # @example Find all the schedule rules that match the name
   #   rules = model_find_objects(standards_data['schedules'], 'name' => schedule_name)
   #   if rules.size.zero?
   #     OpenStudio.logFree(OpenStudio::Error, 'openstudio.standards.Model', "Cannot find data for schedule: #{schedule_name}, will not be created.")
   #     return false
   #   end
-  def model_find_objects(hash_of_objects, search_criteria, capacity = nil, date = nil, area = nil, num_floors = nil, fan_motor_bhp = nil)
+  def model_find_objects(hash_of_objects, search_criteria, capacity = nil, date = nil, area = nil, num_floors = nil, fan_motor_bhp = nil, volume = nil, capacity_per_volume = nil)
     matching_objects = []
     if hash_of_objects.is_a?(Hash) && hash_of_objects.key?('table')
       hash_of_objects = hash_of_objects['table']
@@ -2423,6 +2426,48 @@ def model_find_objects(hash_of_objects, search_criteria, capacity = nil, date =
       end
     end
 
+    # If volume was specified, narrow down the matching objects
+    unless volume.nil?
+      # Skip objects that don't have fields for minimum_storage and maximum_storage
+      matching_objects = matching_objects.reject { |object| !object.key?('minimum_storage') || !object.key?('maximum_storage') }
+
+      # Skip objects that don't have values specified for minimum_storage and maximum_storage
+      matching_objects = matching_objects.reject { |object| object['minimum_storage'].nil? || object['maximum_storage'].nil? }
+
+      # Skip objects whose the minimum volume is below or maximum volume above the specified volume
+      matching_volume_objects = matching_objects.reject { |object| volume.to_f < object['minimum_storage'].to_f || volume.to_f > object['maximum_storage'].to_f }
+
+      # If no object was found, round the volume down in case the number fell between the limits in the json file.
+      if matching_volume_objects.size.zero?
+        volume *= 0.99
+        # Skip objects whose minimum volume is below or maximum volume above the specified volume
+        matching_objects = matching_objects.reject { |object| volume.to_f <= object['minimum_storage'].to_f || volume.to_f >= object['maximum_storage'].to_f }
+      else
+        matching_objects = matching_volume_objects
+      end
+    end
+
+    # If capacity_per_volume was specified, narrow down the matching objects
+    unless capacity_per_volume.nil?
+      # Skip objects that don't have fields for minimum_capacity_per_storage and maximum_capacity_per_storage
+      matching_objects = matching_objects.reject { |object| !object.key?('minimum_capacity_per_storage') || !object.key?('maximum_capacity_per_storage') }
+
+      # Skip objects that don't have values specified for minimum_capacity_per_storage and maximum_capacity_per_storage
+      matching_objects = matching_objects.reject { |object| object['minimum_capacity_per_storage'].nil? || object['maximum_capacity_per_storage'].nil? }
+
+      # Skip objects whose the minimum capacity_per_volume is below or maximum capacity_per_volume above the specified capacity_per_volume
+      matching_capacity_per_volume_objects = matching_objects.reject { |object| capacity_per_volume.to_f <= object['minimum_capacity_per_storage'].to_f || capacity_per_volume.to_f >= object['maximum_capacity_per_storage'].to_f }
+
+      # If no object was found, round the volume down in case the number fell between the limits in the json file.
+      if matching_capacity_per_volume_objects.size.zero?
+        capacity_per_volume *= 0.99
+        # Skip objects whose minimum capacity_per_volume is below or maximum capacity_per_volume above the specified capacity_per_volume
+        matching_objects = matching_objects.reject { |object| capacity_per_volume.to_f <= object['minimum_capacity_per_storage'].to_f || capacity_per_volume.to_f >= object['maximum_capacity_per_storage'].to_f }
+      else
+        matching_objects = matching_capacity_per_volume_objects
+      end
+    end
+
     # If fan_motor_bhp was specified, narrow down the matching objects
     unless fan_motor_bhp.nil?
       # Skip objects that don't have fields for minimum_capacity and maximum_capacity
@@ -2512,8 +2557,8 @@ def model_find_objects(hash_of_objects, search_criteria, capacity = nil, date =
   #   'type' => 'Enclosed',
   #   }
   #   motor_properties = self.model.find_object(motors, search_criteria, capacity: 2.5)
-  def model_find_object(hash_of_objects, search_criteria, capacity = nil, date = nil, area = nil, num_floors = nil, fan_motor_bhp = nil)
-    matching_objects = model_find_objects(hash_of_objects, search_criteria, capacity, date, area, num_floors, fan_motor_bhp)
+  def model_find_object(hash_of_objects, search_criteria, capacity = nil, date = nil, area = nil, num_floors = nil, fan_motor_bhp = nil, volume = nil, capacity_per_volume = nil)
+    matching_objects = model_find_objects(hash_of_objects, search_criteria, capacity, date, area, num_floors, fan_motor_bhp, volume, capacity_per_volume)
 
     # Check the number of matching objects found
     if matching_objects.size.zero?

lib/openstudio-standards/standards/Standards.WaterHeaterMixed.rb

@@ -54,23 +54,15 @@ def water_heater_mixed_apply_efficiency(water_heater_mixed)
       OpenStudio.logFree(OpenStudio::Warn, 'openstudio.standards.WaterHeaterMixed', "For #{water_heater_mixed.name}, fuel type of #{fuel_type} is not yet supported, standard will not be applied.")
     end
 
-    # Get the water heater properties
-    search_criteria = {}
-    search_criteria['template'] = template
-    search_criteria['fuel_type'] = fuel_type
-    wh_props = model_find_object(standards_data['water_heaters'], search_criteria, capacity_btu_per_hr)
-    unless wh_props
-      OpenStudio.logFree(OpenStudio::Warn, 'openstudio.standards.WaterHeaterMixed', "For #{water_heater_mixed.name}, cannot find water heater properties, cannot apply efficiency standard.")
-      return false
-    end
+    wh_props = water_heater_mixed_get_efficiency_requirement(water_heater_mixed, fuel_type, capacity_btu_per_hr, volume_gal)
+    return false if wh_props == {}
 
     # Calculate the water heater efficiency and
     # skin loss coefficient (UA) using different methods,
     # depending on the metrics specified by the standard
     water_heater_efficiency = nil
     ua_btu_per_hr_per_f = nil
 
-    # Rarely specified by thermal efficiency alone
     if wh_props['thermal_efficiency'] && !wh_props['standby_loss_capacity_allowance']
       thermal_efficiency = wh_props['thermal_efficiency']
       water_heater_efficiency = thermal_efficiency
@@ -98,20 +90,25 @@ def water_heater_mixed_apply_efficiency(water_heater_mixed)
         vol_drt = wh_props['uniform_energy_factor_volume_allowance']
         uniform_energy_factor = base_uniform_energy_factor - (vol_drt * volume_gal)
       end
-      energy_factor = water_heater_convert_uniform_energy_factor_to_energy_factor(fuel_type, uniform_energy_factor, capacity_btu_per_hr, volume_gal)
+      energy_factor = water_heater_convert_uniform_energy_factor_to_energy_factor(water_heater_mixed, fuel_type, uniform_energy_factor, capacity_btu_per_hr, volume_gal)
       water_heater_efficiency, ua_btu_per_hr_per_f = water_heater_convert_energy_factor_to_thermal_efficiency_and_ua(fuel_type, energy_factor, capacity_btu_per_hr)
       # Two booster water heaters
       ua_btu_per_hr_per_f = water_heater_mixed.name.to_s.include?('Booster') ? ua_btu_per_hr_per_f * 2 : ua_btu_per_hr_per_f
     end
 
     # Typically specified this way for large electric water heaters
-    if wh_props['standby_loss_base'] && wh_props['standby_loss_volume_allowance']
+    if wh_props['standby_loss_base'] && (wh_props['standby_loss_volume_allowance'] || wh_props['standby_loss_square_root_volume_allowance'])
       # Fixed water heater efficiency per PNNL
       water_heater_efficiency = 1.0
       # Calculate the max allowable standby loss (SL)
       sl_base = wh_props['standby_loss_base']
-      sl_drt = wh_props['standby_loss_volume_allowance']
-      sl_btu_per_hr = sl_base + (sl_drt * Math.sqrt(volume_gal))
+      if wh_props['standby_loss_square_root_volume_allowance']
+        sl_drt = wh_props['standby_loss_square_root_volume_allowance']
+        sl_btu_per_hr = sl_base + (sl_drt * Math.sqrt(volume_gal))
+      else # standby_loss_volume_allowance
+        sl_drt = wh_props['standby_loss_volume_allowance']
+        sl_btu_per_hr = sl_base + (sl_drt * volume_gal)
+      end
       # Calculate the skin loss coefficient (UA)
       ua_btu_per_hr_per_f = @instvarbuilding_type == 'MidriseApartment' ? sl_btu_per_hr / 70 * 23 :  sl_btu_per_hr / 70
       ua_btu_per_hr_per_f = water_heater_mixed.name.to_s.include?('Booster') ? ua_btu_per_hr_per_f * 2 : ua_btu_per_hr_per_f
@@ -124,21 +121,28 @@ def water_heater_mixed_apply_efficiency(water_heater_mixed)
       # Calculate the percent loss per hr
       hr_loss_base = wh_props['hourly_loss_base']
       hr_loss_allow = wh_props['hourly_loss_volume_allowance']
-      hrly_loss_pct = hr_loss_base + (hr_loss_allow / volume_gal) / 100.0
+      hrly_loss_pct = hr_loss_base + hr_loss_allow / volume_gal
       # Convert to Btu/hr, assuming:
       # Water at 120F, density = 8.25 lb/gal
       # 1 Btu to raise 1 lb of water 1 F
       # Therefore 8.25 Btu / gal of water * deg F
       # 70F delta-T between water and zone
-      hrly_loss_btu_per_hr = hrly_loss_pct * volume_gal * 8.25 * 70
+      hrly_loss_btu_per_hr = (hrly_loss_pct / 100) * volume_gal * 8.25 * 70
       # Calculate the skin loss coefficient (UA)
       ua_btu_per_hr_per_f = hrly_loss_btu_per_hr / 70
     end
 
     # Typically specified this way for large natural gas water heaters
-    if wh_props['standby_loss_capacity_allowance'] && wh_props['standby_loss_volume_allowance'] && wh_props['thermal_efficiency']
+    if wh_props['standby_loss_capacity_allowance'] && (wh_props['standby_loss_volume_allowance'] || wh_props['standby_loss_square_root_volume_allowance']) && wh_props['thermal_efficiency']
       sl_cap_adj = wh_props['standby_loss_capacity_allowance']
-      sl_vol_drt = wh_props['standby_loss_volume_allowance']
+      if !wh_props['standby_loss_volume_allowance'].nil?
+        sl_vol_drt = wh_props['standby_loss_volume_allowance']
+      elsif !wh_props['standby_loss_square_root_volume_allowance'].nil?
+        sl_vol_drt = wh_props['standby_loss_square_root_volume_allowance']
+      else
+        OpenStudio.logFree(OpenStudio::Warn, 'openstudio.standards.WaterHeaterMixed', "For #{water_heater_mixed.name}, could not retrieve the standby loss volume allowance.")
+        return false
+      end
       et = wh_props['thermal_efficiency']
       # Estimate storage tank volume
       tank_volume = volume_gal > 100 ? (volume_gal - 100).round(0) : 0
@@ -194,6 +198,56 @@ def water_heater_mixed_apply_efficiency(water_heater_mixed)
     return true
   end
 
+  # @param water_heater_mixed [OpenStudio::Model::WaterHeaterMixed] water heater mixed object
+  # @param fuel_type [Float] water heater fuel type
+  # @param capacity_btu_per_hr [Float] water heater capacity in Btu/h
+  # @param volume_gal [Float] water heater gallons of storage
+  # @return [Hash] returns a hash wwith the applicable efficiency requirements
+  def water_heater_mixed_get_efficiency_requirement(water_heater_mixed, fuel_type, capacity_btu_per_hr, volume_gal)
+    # Get the water heater properties
+    search_criteria = {}
+    search_criteria['template'] = template
+    search_criteria['fuel_type'] = fuel_type
+    search_criteria['equipment_type'] = 'Storage Water Heaters'
+
+    # Search base on capacity first
+    wh_props_capacity = model_find_objects(standards_data['water_heaters'], search_criteria, capacity_btu_per_hr)
+    wh_props_capacity_and_volume = model_find_objects(standards_data['water_heaters'], search_criteria, capacity_btu_per_hr, nil, nil, nil, nil, volume_gal.round(0))
+    wh_props_capacity_and_capacity_btu_per_hr = model_find_objects(standards_data['water_heaters'], search_criteria, capacity_btu_per_hr, nil, nil, nil, nil, nil, capacity_btu_per_hr)
+    wh_props_capacity_and_volume_and_capacity_per_volume = model_find_objects(standards_data['water_heaters'], search_criteria, capacity_btu_per_hr, nil, nil, nil, nil, volume_gal, capacity_btu_per_hr / volume_gal)
+
+    # We consider that the lookup is successful if only one set of record is returned
+    if wh_props_capacity.size == 1
+      wh_props = wh_props_capacity[0]
+    elsif wh_props_capacity_and_volume.size == 1
+      wh_props = wh_props_capacity_and_volume[0]
+    elsif wh_props_capacity_and_capacity_btu_per_hr == 1
+      wh_props = wh_props_capacity_and_capacity_btu_per_hr[0]
+    elsif wh_props_capacity_and_volume_and_capacity_per_volume == 1
+      wh_props = wh_props_capacity_and_volume_and_capacity_per_volume[0]
+    else
+      # Search again with additional criteria
+      search_criteria = water_heater_mixed_additional_search_criteria(water_heater_mixed, search_criteria)
+      wh_props_capacity = model_find_objects(standards_data['water_heaters'], search_criteria, capacity_btu_per_hr)
+      wh_props_capacity_and_volume = model_find_objects(standards_data['water_heaters'], search_criteria, capacity_btu_per_hr, nil, nil, nil, nil, volume_gal.round(0))
+      wh_props_capacity_and_capacity_btu_per_hr = model_find_objects(standards_data['water_heaters'], search_criteria, capacity_btu_per_hr, nil, nil, nil, nil, nil, capacity_btu_per_hr)
+      wh_props_capacity_and_volume_and_capacity_per_volume = model_find_objects(standards_data['water_heaters'], search_criteria, capacity_btu_per_hr, nil, nil, nil, nil, volume_gal, capacity_btu_per_hr / volume_gal)
+      if wh_props_capacity.size == 1
+        wh_props = wh_props_capacity[0]
+      elsif wh_props_capacity_and_volume.size == 1
+        wh_props = wh_props_capacity_and_volume[0]
+      elsif wh_props_capacity_and_capacity_btu_per_hr == 1
+        wh_props = wh_props_capacity_and_capacity_btu_per_hr[0]
+      elsif wh_props_capacity_and_volume_and_capacity_per_volume == 1
+        wh_props = wh_props_capacity_and_volume_and_capacity_per_volume[0]
+      else
+        return {}
+      end
+    end
+
+    return wh_props
+  end
+
   # Applies the correct fuel type for the water heaters
   # in the baseline model.  For most standards and for most building
   # types, the baseline uses the same fuel type as the proposed.
@@ -257,12 +311,13 @@ def water_heater_determine_sub_type(fuel_type, capacity_btu_per_hr, volume_gal)
 
   # Convert Uniform Energy Factor (UEF) to Energy Factor (EF)
   #
+  # @param water_heater_mixed [OpenStudio::Model::WaterHeaterMixed] water heater mixed object
   # @param fuel_type [String] water heater fuel type
   # @param uniform_energy_factor [Float] water heater Uniform Energy Factor (UEF)
   # @param capacity_btu_per_hr [Float] water heater capacity
   # @param volume_gal [Float] water heater storage volume in gallons
   # @return [Float] returns Energy Factor (EF)
-  def water_heater_convert_uniform_energy_factor_to_energy_factor(fuel_type, uniform_energy_factor, capacity_btu_per_hr, volume_gal)
+  def water_heater_convert_uniform_energy_factor_to_energy_factor(water_heater_mixed, fuel_type, uniform_energy_factor, capacity_btu_per_hr, volume_gal)
     # Get water heater sub type
     sub_type = water_heater_determine_sub_type(fuel_type, capacity_btu_per_hr, volume_gal)
 
@@ -319,4 +374,13 @@ def water_heater_convert_energy_factor_to_thermal_efficiency_and_ua(fuel_type, e
 
     return water_heater_efficiency, ua_btu_per_hr_per_f
   end
+
+  # Add additional search criteria for water heater lookup efficiency.
+  #
+  # @param water_heater_mixed [OpenStudio::Model::WaterHeaterMixed] water heater mixed object
+  # @param search_criteria [Hash] search criteria for looking up water heater data
+  # @return [Hash] updated search criteria
+  def water_heater_mixed_additional_search_criteria(water_heater_mixed, search_criteria)
+    return search_criteria
+  end
 end