Building Energy Standards Motors Data Update

lib/openstudio-standards.rb

@@ -280,6 +280,7 @@ module OpenstudioStandards
   require_relative "#{stds}/Standards.HeaderedPumpsVariableSpeed"
   require_relative "#{stds}/Standards.HeatExchangerSensLat"
   require_relative "#{stds}/Standards.Model"
+  require_relative "#{stds}/Standards.Motor"
   require_relative "#{stds}/Standards.PlanarSurface"
   require_relative "#{stds}/Standards.PlantLoop"
   require_relative "#{stds}/Standards.PumpConstantSpeed"
@@ -333,6 +334,7 @@ module OpenstudioStandards
   require_relative "#{stds}/ashrae_90_1/ashrae_90_1_2013/ashrae_90_1_2013.CoolingTowerVariableSpeed"
   require_relative "#{stds}/ashrae_90_1/ashrae_90_1_2013/ashrae_90_1_2013.FanVariableVolume"
   require_relative "#{stds}/ashrae_90_1/ashrae_90_1_2013/ashrae_90_1_2013.Model"
+  require_relative "#{stds}/ashrae_90_1/ashrae_90_1_2013/ashrae_90_1_2013.Motor"
   require_relative "#{stds}/ashrae_90_1/ashrae_90_1_2013/ashrae_90_1_2013.PlantLoop"
   require_relative "#{stds}/ashrae_90_1/ashrae_90_1_2013/ashrae_90_1_2013.Space"
   require_relative "#{stds}/ashrae_90_1/ashrae_90_1_2013/ashrae_90_1_2013.ThermalZone"
@@ -348,6 +350,7 @@ module OpenstudioStandards
   require_relative "#{stds}/ashrae_90_1/ashrae_90_1_2016/ashrae_90_1_2016.CoolingTowerVariableSpeed"
   require_relative "#{stds}/ashrae_90_1/ashrae_90_1_2016/ashrae_90_1_2016.FanVariableVolume"
   require_relative "#{stds}/ashrae_90_1/ashrae_90_1_2016/ashrae_90_1_2016.Model"
+  require_relative "#{stds}/ashrae_90_1/ashrae_90_1_2016/ashrae_90_1_2016.Motor"
   require_relative "#{stds}/ashrae_90_1/ashrae_90_1_2016/ashrae_90_1_2016.Space"
   require_relative "#{stds}/ashrae_90_1/ashrae_90_1_2016/ashrae_90_1_2016.ThermalZone"
   # 90.1-2019
@@ -362,6 +365,7 @@ module OpenstudioStandards
   require_relative "#{stds}/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.CoolingTowerVariableSpeed"
   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.Model"
+  require_relative "#{stds}/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.Motor"
   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"

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

@@ -45,13 +45,6 @@ def prototype_fan_apply_prototype_fan_efficiency(fan)
       allowed_hp = 0.01
     end
 
-    # Minimum motor size for efficiency lookup
-    # is 1 HP unless the motor serves an exhaust fan,
-    # a powered VAV terminal, or a fan coil unit.
-    if !fan_small_fan?(fan) && allowed_hp < 1.0
-      allowed_hp = 1.01
-    end
-
     # Find the motor efficiency
     motor_eff, nominal_hp = fan_standard_minimum_motor_efficiency_and_size(fan, allowed_hp)
 

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

@@ -84,28 +84,55 @@ def cooling_tower_apply_minimum_power_per_flow(cooling_tower)
     # per method used in PNNL prototype buildings.
     # Assumes that the fan brake horsepower is 90%
     # of the fan nameplate rated motor power.
-    fan_motor_nameplate_hp = design_water_flow_gpm / min_gpm_per_hp
-    fan_bhp = 0.9 * fan_motor_nameplate_hp
-
-    # Lookup the minimum motor efficiency
+    # Source: Thornton et al. (2011), Achieving the 30% Goal: Energy and Cost Savings Analysis of ASHRAE Standard 90.1-2010, Section 4.5.4
+    nominal_hp = design_water_flow_gpm / min_gpm_per_hp
+    fan_bhp = 0.9 * nominal_hp
     fan_motor_eff = 0.85
-    motors = standards_data['motors']
 
-    # Assuming all fan motors are 4-pole Enclosed
-    search_criteria = {
-      'template' => template,
-      'number_of_poles' => 4.0,
-      'type' => 'Enclosed'
-    }
+    if nominal_hp <= 0.75
+      motor_type = motor_type(nominal_hp)
+      motor_properties = motor_fractional_hp_efficiencies(nominal_hp, motor_type = motor_type)
+    else
+      # Lookup the minimum motor efficiency
+      motors = standards_data['motors']
+
+      # Assuming all fan motors are 4-pole Enclosed
+      search_criteria = {
+        'template' => template,
+        'number_of_poles' => 4.0,
+        'type' => 'Enclosed'
+      }
+
+      # Use the efficiency largest motor efficiency when BHP is greater than the largest size for which a requirement is provided
+      data = model_find_objects(motors, search_criteria)
+      if data.empty?
+        search_criteria = {
+          'template' => template,
+          'type' => nil
+        }
+        data = model_find_objects(motors, search_criteria)
+      end
+      maximum_capacity = model_find_maximum_value(data, 'maximum_capacity')
+      if fan_bhp > maximum_capacity
+        fan_bhp = maximum_capacity
+      end
+
+      motor_properties = model_find_object(motors, search_criteria, capacity = nil, date = Date.today, area = nil, num_floors = nil, fan_motor_bhp = fan_bhp)
+
+      if motor_properties.nil?
+        # Retry without the date
+        motor_properties = model_find_object(motors, search_criteria, capacity = nil, date = nil, area = nil, num_floors = nil, fan_motor_bhp = fan_bhp)
+      end
+    end
 
-    motor_properties = model_find_object(motors, search_criteria, fan_motor_nameplate_hp)
     if motor_properties.nil?
-      OpenStudio.logFree(OpenStudio::Error, 'openstudio.standards.CoolingTower', "For #{cooling_tower.name}, could not find motor properties using search criteria: #{search_criteria}, motor_hp = #{fan_motor_nameplate_hp} hp.")
-      return false
+      OpenStudio.logFree(OpenStudio::Error, 'openstudio.standards.CoolingTower', "For #{cooling_tower.name}, could not find motor properties using search criteria: #{search_criteria}, motor_hp = #{nominal_hp} hp. Using a default value of #{fan_motor_eff}.")
     end
 
-    fan_motor_eff = motor_properties['nominal_full_load_efficiency']
-    nominal_hp = motor_properties['maximum_capacity'].to_f.round(1)
+    unless motor_properties.nil?
+      fan_motor_eff = motor_properties['nominal_full_load_efficiency']
+      nominal_hp = motor_properties['maximum_capacity'].to_f.round(1)
+    end
     # Round to nearest whole HP for niceness
     if nominal_hp >= 2
       nominal_hp = nominal_hp.round
@@ -116,7 +143,7 @@ def cooling_tower_apply_minimum_power_per_flow(cooling_tower)
     # Convert to W
     fan_motor_actual_power_w = fan_motor_actual_power_hp * 745.7 # 745.7 W/HP
 
-    OpenStudio.logFree(OpenStudio::Info, 'openstudio.standards.CoolingTower', "For #{cooling_tower.name}, allowed fan motor nameplate hp = #{fan_motor_nameplate_hp.round(1)} hp, fan brake horsepower = #{fan_bhp.round(1)}, and fan motor actual power = #{fan_motor_actual_power_hp.round(1)} hp (#{fan_motor_actual_power_w.round} W) at #{fan_motor_eff} motor efficiency.")
+    OpenStudio.logFree(OpenStudio::Info, 'openstudio.standards.CoolingTower', "For #{cooling_tower.name}, allowed fan motor nameplate hp = #{nominal_hp.round(1)} hp, fan brake horsepower = #{fan_bhp.round(1)}, and fan motor actual power = #{fan_motor_actual_power_hp.round(1)} hp (#{fan_motor_actual_power_w.round} W) at #{fan_motor_eff} motor efficiency.")
 
     # Append the efficiency to the name
     cooling_tower.setName("#{cooling_tower.name} #{min_gpm_per_hp.to_f.round(1)} gpm/hp")

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

@@ -231,7 +231,7 @@ def fan_baseline_impeller_efficiency(fan)
 
   # Determines the minimum fan motor efficiency and nominal size for a given motor bhp.
   # This should be the total brake horsepower with any desired safety factor already included.
-  # This method picks the next nominal motor catgory larger than the required brake horsepower,
+  # This method picks the next nominal motor category larger than the required brake horsepower,
   # and the efficiency is based on that size.
   # For example, if the bhp = 6.3, the nominal size will be 7.5HP and the efficiency
   # for 90.1-2010 will be 91.7% from Table 10.8B.
@@ -243,7 +243,12 @@ def fan_baseline_impeller_efficiency(fan)
   # @return [Array<Double>] minimum motor efficiency (0.0 to 1.0), nominal horsepower
   def fan_standard_minimum_motor_efficiency_and_size(fan, motor_bhp)
     fan_motor_eff = 0.85
-    nominal_hp = motor_bhp
+    # Calculate the allowed fan brake horsepower
+    # per method used in PNNL prototype buildings.
+    # Assumes that the fan brake horsepower is 90%
+    # of the fan nameplate rated motor power.
+    # Source: Thornton et al. (2011), Achieving the 30% Goal: Energy and Cost Savings Analysis of ASHRAE Standard 90.1-2010, Section 4.5.4
+    nominal_hp = motor_bhp * 1.1
 
     # Don't attempt to look up motor efficiency
     # for zero-hp fans, which may occur when there is no
@@ -267,34 +272,40 @@ def fan_standard_minimum_motor_efficiency_and_size(fan, motor_bhp)
     # In this case, use the 0.5 HP for the lookup.
     if fan_small_fan?(fan)
       nominal_hp = 0.5
-    else
-      motor_properties = model_find_object(motors, search_criteria, motor_bhp)
+
+      # Get the efficiency based on the nominal horsepower
+      motor_type = motor_type(nominal_hp)
+      motor_properties = motor_fractional_hp_efficiencies(nominal_hp, motor_type = motor_type)
+
       if motor_properties.nil?
-        OpenStudio.logFree(OpenStudio::Error, 'openstudio.standards.Fan', "For #{fan.name}, could not find motor properties using search criteria: #{search_criteria}, motor_bhp = #{motor_bhp} hp.")
+        OpenStudio.logFree(OpenStudio::Error, 'openstudio.standards.Fan', "For #{fan.name}, could not find nominal motor properties using search criteria: #{search_criteria}, motor_hp = #{nominal_hp} hp.")
         return [fan_motor_eff, nominal_hp]
       end
-
-      nominal_hp = motor_properties['maximum_capacity'].to_f.round(1)
-      # If the biggest fan motor size is hit, use the highest category efficiency
-      if nominal_hp > 9998.0
-        OpenStudio.logFree(OpenStudio::Warn, 'openstudio.standards.Fan', "For #{fan.name}, there is no greater nominal HP.  Use the efficiency of the largest motor category.")
-        nominal_hp = motor_bhp
+    else
+      # Use the efficiency largest motor efficiency when BHP is greater than the largest size for which a requirement is provided
+      data = model_find_objects(motors, search_criteria)
+      maximum_capacity = model_find_maximum_value(data, 'maximum_capacity')
+      if motor_bhp > maximum_capacity
+        motor_bhp = maximum_capacity
       end
 
-      # Round to nearest whole HP for niceness
-      if nominal_hp >= 2
-        nominal_hp = nominal_hp.round
+      motor_properties = model_find_object(motors, search_criteria, capacity = nil, date = Date.today, area = nil, num_floors = nil, fan_motor_bhp = motor_bhp)
+      if motor_properties.nil?
+        # Retry without the date
+        motor_properties = model_find_object(motors, search_criteria, capacity = nil, date = nil, area = nil, num_floors = nil, fan_motor_bhp = motor_bhp)
+        if motor_properties.nil?
+          OpenStudio.logFree(OpenStudio::Error, 'openstudio.standards.Fan', "For #{fan.name}, could not find motor properties using search criteria: #{search_criteria}, motor_bhp = #{motor_bhp} hp.")
+          return [fan_motor_eff, nominal_hp]
+        end
       end
     end
 
-    # Get the efficiency based on the nominal horsepower
-    # Add 0.01 hp to avoid search errors.
-    motor_properties = model_find_object(motors, search_criteria, nominal_hp + 0.01)
-
-    if motor_properties.nil?
-      OpenStudio.logFree(OpenStudio::Error, 'openstudio.standards.Fan', "For #{fan.name}, could not find nominal motor properties using search criteria: #{search_criteria}, motor_hp = #{nominal_hp} hp.")
-      return [fan_motor_eff, nominal_hp]
+    nominal_hp = motor_properties['maximum_capacity'].to_f.round(1)
+    # Round to nearest whole HP for niceness
+    if nominal_hp >= 2
+      nominal_hp = nominal_hp.round
     end
+
     fan_motor_eff = motor_properties['nominal_full_load_efficiency']
 
     return [fan_motor_eff, nominal_hp]

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

@@ -76,27 +76,54 @@ def fluid_cooler_apply_minimum_power_per_flow(fluid_cooler, equipment_type: 'Clo
     # per method used in PNNL prototype buildings.
     # Assumes that the fan brake horsepower is 90%
     # of the fan nameplate rated motor power.
-    fan_motor_nameplate_hp = design_water_flow_gpm / min_gpm_per_hp
-    fan_bhp = 0.9 * fan_motor_nameplate_hp
-
-    # Lookup the minimum motor efficiency
-    motors = standards_data['motors']
-
-    # Assuming all fan motors are 4-pole Enclosed
-    search_criteria = {
-      'template' => template,
-      'number_of_poles' => 4.0,
-      'type' => 'Enclosed'
-    }
+    # Source: Thornton et al. (2011), Achieving the 30% Goal: Energy and Cost Savings Analysis of ASHRAE Standard 90.1-2010, Section 4.5.4
+    nominal_hp = design_water_flow_gpm / min_gpm_per_hp
+    fan_bhp = 0.9 * nominal_hp
+    fan_motor_eff = 0.85
+
+    if nominal_hp <= 0.75
+      motor_type = motor_type(nominal_hp)
+      motor_properties = motor_fractional_hp_efficiencies(nominal_hp, motor_type = motor_type)
+    else
+      # Lookup the minimum motor efficiency
+      motors = standards_data['motors']
+
+      # Assuming all fan motors are 4-pole Enclosed
+      search_criteria = {
+        'template' => template,
+        'number_of_poles' => 4.0,
+        'type' => 'Enclosed'
+      }
+
+      # Use the efficiency largest motor efficiency when BHP is greater than the largest size for which a requirement is provided
+      data = model_find_objects(motors, search_criteria)
+      if data.empty?
+        search_criteria = {
+          'template' => template,
+          'type' => nil
+        }
+        data = model_find_objects(motors, search_criteria)
+      end
+      maximum_capacity = model_find_maximum_value(data, 'maximum_capacity')
+      if fan_bhp > maximum_capacity
+        fan_bhp = maximum_capacity
+      end
+
+      motor_properties = model_find_object(motors, search_criteria, capacity = nil, date = Date.today, area = nil, num_floors = nil, fan_motor_bhp = fan_bhp)
+      if motor_properties.nil?
+        # Retry without the date
+        motor_properties = model_find_object(motors, search_criteria, capacity = nil, date = nil, area = nil, num_floors = nil, fan_motor_bhp = fan_bhp)
+      end
+    end
 
-    motor_properties = model_find_object(motors, search_criteria, fan_motor_nameplate_hp)
     if motor_properties.nil?
-      OpenStudio.logFree(OpenStudio::Error, 'openstudio.standards.FluidCooler', "For #{fluid_cooler.name}, could not find motor properties using search criteria: #{search_criteria}, motor_hp = #{motor_hp} hp.")
-      return false
+      OpenStudio.logFree(OpenStudio::Error, 'openstudio.standards.FluidCooler', "For #{fluid_cooler.name}, could not find motor properties using search criteria: #{search_criteria}, motor_hp = #{norminal_hp} hp. Using a default value of #{fan_motor_eff}.")
     end
 
-    fan_motor_eff = motor_properties['nominal_full_load_efficiency']
-    nominal_hp = motor_properties['maximum_capacity'].to_f.round(1)
+    unless motor_properties.nil?
+      fan_motor_eff = motor_properties['nominal_full_load_efficiency']
+      nominal_hp = motor_properties['maximum_capacity'].to_f.round(1)
+    end
     # Round to nearest whole HP for niceness
     if nominal_hp >= 2
       nominal_hp = nominal_hp.round
@@ -107,7 +134,7 @@ def fluid_cooler_apply_minimum_power_per_flow(fluid_cooler, equipment_type: 'Clo
     # Convert to W
     fan_motor_actual_power_w = fan_motor_actual_power_hp * 745.7 # 745.7 W/HP
 
-    OpenStudio.logFree(OpenStudio::Info, 'openstudio.standards.FluidCooler', "For #{fluid_cooler.name}, allowed fan motor nameplate hp = #{fan_motor_nameplate_hp.round(1)} hp, fan brake horsepower = #{fan_bhp.round(1)}, and fan motor actual power = #{fan_motor_actual_power_hp.round(1)} hp (#{fan_motor_actual_power_w.round} W) at #{fan_motor_eff} motor efficiency.")
+    OpenStudio.logFree(OpenStudio::Info, 'openstudio.standards.FluidCooler', "For #{fluid_cooler.name}, allowed fan motor nameplate hp = #{nominal_hp.round(1)} hp, fan brake horsepower = #{fan_bhp.round(1)}, and fan motor actual power = #{fan_motor_actual_power_hp.round(1)} hp (#{fan_motor_actual_power_w.round} W) at #{fan_motor_eff} motor efficiency.")
 
     # Append the efficiency to the name
     fluid_cooler.setName("#{fluid_cooler.name} #{min_gpm_per_hp.to_f.round(1)} gpm/hp")