Non-transient dwelling unit energy recovery ventilation

data/standards/manage_OpenStudio_Standards.rb

@@ -143,7 +143,7 @@ def unique_properties(sheet_name)
          when 'climate_zones'
            ['name', 'standard']
          when 'energy_recovery'
-           ['template', 'climate_zone', 'under_8000_hours']
+           ['template', 'climate_zone', 'under_8000_hours', 'nontransient_dwelling']
          when 'space_types_lighting_control'
            ['template', 'building_type', 'space_type']
          else
@@ -345,6 +345,7 @@ def export_spreadsheet_to_json(spreadsheet_titles, dataset_type: 'os_stds')
   bool_cols << 'hx'
   bool_cols << 'data_center'
   bool_cols << 'under_8000_hours'
+  bool_cols << 'nontransient_dwelling'
   bool_cols << 'u_value_includes_interior_film_coefficient'
   bool_cols << 'u_value_includes_exterior_film_coefficient'
 

lib/openstudio-standards.rb

@@ -437,6 +437,7 @@ module OpenstudioStandards
   require_relative "#{proto}/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.hvac_systems"
   require_relative "#{proto}/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.AirTerminalSingleDuctVAVReheat"
   require_relative "#{proto}/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.PumpVariableSpeed"
+  require_relative "#{proto}/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.HeatExchangerAirToAirSensibleAndLatent"
   # DOE Ref 1980-2004
   require_relative "#{proto}/ashrae_90_1/doe_ref_1980_2004/doe_ref_1980_2004.AirTerminalSingleDuctVAVReheat"
   require_relative "#{proto}/ashrae_90_1/doe_ref_1980_2004/doe_ref_1980_2004.Model.elevators"

lib/openstudio-standards/prototypes/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.HeatExchangerAirToAirSensibleAndLatent.rb

@@ -0,0 +1,25 @@
+class ASHRAE9012019 < ASHRAE901
+  # @!group Model
+
+  # Set sensible and latent effectiveness at 100 and 75 heating and cooling airflow;
+  # The values are calculated by using ERR, which is introduced in 90.1-2016 Addendum CE
+  #
+  # This function is only used for nontransient dwelling units (Mid-rise and High-rise Apartment)
+  def heat_exchanger_air_to_air_sensible_and_latent_apply_prototype_efficiency_err(heat_exchanger_air_to_air_sensible_and_latent, err, basis, climate_zone)
+    # Assumed to be sensible and latent at all flow
+    err = enthalpy_recovery_ratio_design_to_typical_adjustment(err, climate_zone)
+    full_htg_sens_eff, full_htg_lat_eff, part_htg_sens_eff, part_htg_lat_eff, full_cool_sens_eff, full_cool_lat_eff, part_cool_sens_eff, part_cool_lat_eff = heat_exchanger_air_to_air_sensible_and_latent_enthalpy_recovery_ratio_to_effectiveness(err, basis)
+
+    heat_exchanger_air_to_air_sensible_and_latent.setSensibleEffectivenessat100HeatingAirFlow(full_htg_sens_eff)
+    heat_exchanger_air_to_air_sensible_and_latent.setLatentEffectivenessat100HeatingAirFlow(full_htg_lat_eff)
+    heat_exchanger_air_to_air_sensible_and_latent.setSensibleEffectivenessat75HeatingAirFlow(part_htg_sens_eff)
+    heat_exchanger_air_to_air_sensible_and_latent.setLatentEffectivenessat75HeatingAirFlow(part_htg_lat_eff)
+    heat_exchanger_air_to_air_sensible_and_latent.setSensibleEffectivenessat100CoolingAirFlow(full_cool_sens_eff)
+    heat_exchanger_air_to_air_sensible_and_latent.setLatentEffectivenessat100CoolingAirFlow(full_cool_lat_eff)
+    heat_exchanger_air_to_air_sensible_and_latent.setSensibleEffectivenessat75CoolingAirFlow(part_cool_sens_eff)
+    heat_exchanger_air_to_air_sensible_and_latent.setLatentEffectivenessat75CoolingAirFlow(part_cool_lat_eff)
+
+    OpenStudio.logFree(OpenStudio::Info, 'openstudio.standards.HeatExchangerSensLat', "For #{heat_exchanger_air_to_air_sensible_and_latent.name}: Set sensible and latent effectiveness calculated by using ERR.")
+    return true
+  end
+end

lib/openstudio-standards/prototypes/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.Model.rb

@@ -364,4 +364,50 @@ def model_add_lights_shutoff(model)
 
     return true
   end
+
+  # This function is used to add zone ERV
+  #
+  # This function is only used for nontransient dwelling units (Mid-rise and High-rise Apartment)
+  def model_apply_prototype_hvac_efficiency_adjustments(model)
+    # identify the building type
+    building_data = model_get_building_climate_zone_and_building_type(model)
+    building_type = building_data['building_type']
+    if building_type == 'MidriseApartment' || building_type == 'HighriseApartment'
+      # update effectiveness based err
+      climate_zone = building_data['climate_zone']
+      model.getAirLoopHVACs.each do |air_loop_hvac|
+        if air_loop_hvac_energy_recovery_ventilator_required?(air_loop_hvac, climate_zone)
+          # calculate the number of system operating hours based on the availability schedule
+          under_8000_hour = false
+          avail_sch = air_loop_hvac.availabilitySchedule
+          if avail_sch == air_loop_hvac.model.alwaysOnDiscreteSchedule
+            under_8000_hour = false
+          elsif avail_sch.to_ScheduleRuleset.is_initialized
+            avail_sch = avail_sch.to_ScheduleRuleset.get
+            ann_op_hrs = schedule_ruleset_annual_hours_above_value(avail_sch, 0.0)
+            if ann_op_hrs < 8000
+              under_8000_hour = true
+            end
+          else
+            OpenStudio.logFree(OpenStudio::Warn, 'openstudio.ashrae_90_1_2019.AirLoopHVAC', "For #{air_loop_hvac.name}: could not determine annual operating hours. Assuming less than 8,000 for ERV determination.")
+          end
+          # determine search_criteria
+          search_criteria = {
+            'template' => template,
+            'climate_zone' => climate_zone,
+            'under_8000_hour' => under_8000_hour,
+            'nontransient_dwelling' => true
+          }
+          zones = air_loop_hvac.thermalZones
+          model_add_zone_erv_err(model, zones, search_criteria)
+        end
+      end
+    else
+      # ERVs
+      # # Applies the DOE Prototype Building assumption that ERVs use
+      # # enthalpy wheels and therefore exceed the minimum effectiveness specified by 90.1
+      model.getHeatExchangerAirToAirSensibleAndLatents.each { |obj| heat_exchanger_air_to_air_sensible_and_latent_apply_prototype_efficiency(obj) }
+      return true
+    end
+  end
 end

lib/openstudio-standards/prototypes/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.hvac_systems.rb

@@ -8,4 +8,61 @@ def model_cw_loop_cooling_tower_fan_type(model)
     fan_type = 'Variable Speed Fan'
     return fan_type
   end
+
+  # Add zone ERV
+  # This function adds supply fan, exhaust fan, heat exchanger, and zone hvac
+  #
+  # This function is only used for nontransient dwelling units (Mid-rise and High-rise Apartment)
+  def model_add_zone_erv_err(model, thermal_zones, search_criteria)
+    ervs = []
+    thermal_zones.each do |zone|
+      OpenStudio.logFree(OpenStudio::Info, 'openstudio.Model.Model', "Adding ERV for #{zone.name}.")
+
+      # determine the OA requirement for this zone
+      min_oa_flow_m3_per_s_per_m2 = thermal_zone_outdoor_airflow_rate_per_area(zone)
+      supply_fan = create_fan_by_name(model,
+                                      'ERV_Supply_Fan',
+                                      fan_name: "#{zone.name} ERV Supply Fan")
+      impeller_eff = fan_baseline_impeller_efficiency(supply_fan)
+      fan_change_impeller_efficiency(supply_fan, impeller_eff)
+      exhaust_fan = create_fan_by_name(model,
+                                       'ERV_Supply_Fan',
+                                       fan_name: "#{zone.name} ERV Exhaust Fan")
+      fan_change_impeller_efficiency(exhaust_fan, impeller_eff)
+
+      erv_controller = OpenStudio::Model::ZoneHVACEnergyRecoveryVentilatorController.new(model)
+      erv_controller.setName("#{zone.name} ERV Controller")
+
+      climate_zone = search_criteria['climate_zone']
+      erv_err = model_find_object(standards_data['energy_recovery'], search_criteria)
+      err_basis = erv_err['err_basis']
+      err = erv_err['err']
+
+      heat_exchanger = OpenStudio::Model::HeatExchangerAirToAirSensibleAndLatent.new(model)
+      heat_exchanger.setName("#{zone.name} ERV HX")
+      heat_exchanger.setHeatExchangerType('Plate')
+      heat_exchanger.setEconomizerLockout(false)
+      heat_exchanger.setSupplyAirOutletTemperatureControl(false)
+      heat_exchanger_air_to_air_sensible_and_latent_apply_prototype_efficiency_err(heat_exchanger, err, err_basis, climate_zone)
+
+      zone_hvac = OpenStudio::Model::ZoneHVACEnergyRecoveryVentilator.new(model, heat_exchanger, supply_fan, exhaust_fan)
+      zone_hvac.setName("#{zone.name} ERV")
+      zone_hvac.setVentilationRateperUnitFloorArea(min_oa_flow_m3_per_s_per_m2)
+      zone_hvac.setController(erv_controller)
+      zone_hvac.addToThermalZone(zone)
+
+      # ensure the ERV takes priority, so ventilation load is included when treated by other zonal systems
+      # From EnergyPlus I/O reference:
+      # "For situations where one or more equipment types has limited capacity or limited control capability, order the
+      #  sequence so that the most controllable piece of equipment runs last. For example, with a dedicated outdoor air
+      #  system (DOAS), the air terminal for the DOAS should be assigned Heating Sequence = 1 and Cooling Sequence = 1.
+      #  Any other equipment should be assigned sequence 2 or higher so that it will see the net load after the DOAS air
+      #  is added to the zone."
+      zone.setCoolingPriority(zone_hvac.to_ModelObject.get, 1)
+      zone.setHeatingPriority(zone_hvac.to_ModelObject.get, 1)
+
+      ervs << zone_hvac
+      return ervs
+    end
+  end
 end

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

@@ -3,20 +3,20 @@ class Standard
 
   # Sets the minimum effectiveness of the heat exchanger per
   # the standard.
-  def heat_exchanger_air_to_air_sensible_and_latent_apply_efficiency(heat_exchanger_air_to_air_sensible_and_latent)
+  def heat_exchanger_air_to_air_sensible_and_latent_apply_effectiveness(heat_exchanger_air_to_air_sensible_and_latent)
     # Assumed to be sensible and latent at all flow
-    min_effct = heat_exchanger_air_to_air_sensible_and_latent_minimum_efficiency(heat_exchanger_air_to_air_sensible_and_latent)
+    full_htg_sens_eff, full_htg_lat_eff, part_htg_sens_eff, part_htg_lat_eff, full_cool_sens_eff, full_cool_lat_eff, part_cool_sens_eff, part_cool_lat_eff = heat_exchanger_air_to_air_sensible_and_latent_minimum_effectiveness(heat_exchanger_air_to_air_sensible_and_latent)
 
-    heat_exchanger_air_to_air_sensible_and_latent.setSensibleEffectivenessat100HeatingAirFlow(min_effct)
-    heat_exchanger_air_to_air_sensible_and_latent.setLatentEffectivenessat100HeatingAirFlow(min_effct)
-    heat_exchanger_air_to_air_sensible_and_latent.setSensibleEffectivenessat75HeatingAirFlow(min_effct)
-    heat_exchanger_air_to_air_sensible_and_latent.setLatentEffectivenessat75HeatingAirFlow(min_effct)
-    heat_exchanger_air_to_air_sensible_and_latent.setSensibleEffectivenessat100CoolingAirFlow(min_effct)
-    heat_exchanger_air_to_air_sensible_and_latent.setLatentEffectivenessat100CoolingAirFlow(min_effct)
-    heat_exchanger_air_to_air_sensible_and_latent.setSensibleEffectivenessat75CoolingAirFlow(min_effct)
-    heat_exchanger_air_to_air_sensible_and_latent.setLatentEffectivenessat75CoolingAirFlow(min_effct)
+    heat_exchanger_air_to_air_sensible_and_latent.setSensibleEffectivenessat100HeatingAirFlow(full_htg_sens_eff)
+    heat_exchanger_air_to_air_sensible_and_latent.setLatentEffectivenessat100HeatingAirFlow(full_htg_lat_eff)
+    heat_exchanger_air_to_air_sensible_and_latent.setSensibleEffectivenessat75HeatingAirFlow(part_htg_sens_eff)
+    heat_exchanger_air_to_air_sensible_and_latent.setLatentEffectivenessat75HeatingAirFlow(part_htg_lat_eff)
+    heat_exchanger_air_to_air_sensible_and_latent.setSensibleEffectivenessat100CoolingAirFlow(full_cool_sens_eff)
+    heat_exchanger_air_to_air_sensible_and_latent.setLatentEffectivenessat100CoolingAirFlow(full_cool_lat_eff)
+    heat_exchanger_air_to_air_sensible_and_latent.setSensibleEffectivenessat75CoolingAirFlow(part_cool_sens_eff)
+    heat_exchanger_air_to_air_sensible_and_latent.setLatentEffectivenessat75CoolingAirFlow(part_cool_lat_eff)
 
-    OpenStudio.logFree(OpenStudio::Info, 'openstudio.standards.HeatExchangerSensLat', "For #{heat_exchanger_air_to_air_sensible_and_latent.name}: Set sensible and latent effectiveness to #{(min_effct * 100).round}%.")
+    OpenStudio.logFree(OpenStudio::Info, 'openstudio.standards.HeatExchangerSensLat', "For #{heat_exchanger_air_to_air_sensible_and_latent.name}: Set sensible and latent effectiveness.")
 
     return true
   end
@@ -26,8 +26,64 @@ def heat_exchanger_air_to_air_sensible_and_latent_apply_efficiency(heat_exchange
   # effectiveness at all flow rates.
   #
   # @param heat_exchanger_air_to_air_sensible_and_latent [OpenStudio::Model::HeatExchangerAirToAirSensibleAndLatent] the heat exchanger
-  def heat_exchanger_air_to_air_sensible_and_latent_minimum_efficiency(heat_exchanger_air_to_air_sensible_and_latent)
-    min_effct = 0.5
-    return min_effct
+  def heat_exchanger_air_to_air_sensible_and_latent_minimum_effectiveness(heat_exchanger_air_to_air_sensible_and_latent)
+    full_htg_sens_eff = 0.5
+    full_htg_lat_eff = 0.5
+    part_htg_sens_eff = 0.5
+    part_htg_lat_eff = 0.5
+    full_cool_sens_eff = 0.5
+    full_cool_lat_eff = 0.5
+    part_cool_sens_eff = 0.5
+    part_cool_lat_eff = 0.5
+    return full_htg_sens_eff, full_htg_lat_eff, part_htg_sens_eff, part_htg_lat_eff, full_cool_sens_eff, full_cool_lat_eff, part_cool_sens_eff, part_cool_lat_eff
+  end
+
+  # Adjust ERR from design conditions to ERR for typical conditions.
+  # This is only applies to the 2B and 3B climate zones. In these
+  # climate zones a 50% ERR at typical condition leads a ERR > 50%,
+  # the ERR is thus scaled down.
+  #
+  # @param err [float] Enthalpy Recovery Ratio (ERR)
+  # @param climate_zone [String] climate zone
+  # @return [float] adjusted ERR
+  def enthalpy_recovery_ratio_design_to_typical_adjustment(err, climate_zone)
+    if climate_zone.include? '2B'
+      err /= 0.65 / 0.55
+    elsif climate_zone.include? '3B'
+      err /= 0.62 / 0.55
+    end
+
+    return err
+  end
+
+  # Calculate a heat exchanger's effectiveness for a specific ERR and design basis.
+  # Regressions were determined based available manufacturer data.
+  #
+  # @param err [float] Enthalpy Recovery Ratio (ERR)
+  # @param basis [String] basis for effectiveness calculation, either cooling or heating
+  # @return [Array] heating and cooling heat exchanger effectiveness at 100% and 75% nominal airflow
+  def heat_exchanger_air_to_air_sensible_and_latent_enthalpy_recovery_ratio_to_effectiveness(err, basis)
+    case basis
+      when 'Cooling'
+        full_htg_sens_eff = (20.707 * err**2 + 41.354 * err + 40.755) / 100
+        full_htg_lat_eff = (127.45 * err - 18.625) / 100
+        part_htg_sens_eff = (-0.1214 * err + 1.111) * full_htg_sens_eff
+        part_htg_lat_eff = (-0.3405 * err + 1.2732) * full_htg_lat_eff
+        full_cool_sens_eff = (70.689 * err + 30.789) / 100
+        full_cool_lat_eff = (48.054 * err**2 + 83.082 * err - 12.881) / 100
+        part_cool_sens_eff = (-0.1214 * err + 1.111) * full_cool_sens_eff
+        part_cool_lat_eff = (-0.3982 * err  + 1.3151) * full_cool_lat_eff
+      when 'Heating'
+        full_htg_sens_eff = err
+        full_htg_lat_eff = 0.0
+        part_htg_sens_eff = (-0.1214 * err + 1.111) * full_htg_sens_eff
+        part_htg_lat_eff = 0.0
+        full_cool_sens_eff = err * (70.689 * err + 30.789) / (20.707 * err**2 + 41.354 * err + 40.755)
+        full_cool_lat_eff = 0.0
+        part_cool_sens_eff = (-0.1214 * err + 1.111) * full_cool_sens_eff
+        part_cool_lat_eff = 0.0
+    end
+
+    return full_htg_sens_eff, full_htg_lat_eff, part_htg_sens_eff, part_htg_lat_eff, full_cool_sens_eff, full_cool_lat_eff, part_cool_sens_eff, part_cool_lat_eff
   end
 end

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

@@ -1548,7 +1548,7 @@ def model_apply_hvac_efficiency_standard(model, climate_zone, apply_controls: tr
     model.getEvaporativeFluidCoolerTwoSpeeds.sort.each { |obj| fluid_cooler_apply_minimum_power_per_flow(obj, equipment_type: 'Closed Cooling Tower') }
 
     # ERVs
-    model.getHeatExchangerAirToAirSensibleAndLatents.each { |obj| heat_exchanger_air_to_air_sensible_and_latent_apply_efficiency(obj) }
+    model.getHeatExchangerAirToAirSensibleAndLatents.each { |obj| heat_exchanger_air_to_air_sensible_and_latent_apply_effectiveness(obj) }
 
     # Gas Heaters
     model.getCoilHeatingGass.sort.each { |obj| coil_heating_gas_apply_efficiency_and_curves(obj) }