Merge pull request #741 from NREL/cfis_addendum_e

301-2022 Addendum E (CFIS systems), part 1

.github/workflows/config.yml

@@ -191,7 +191,7 @@ jobs:
           mkdir workflow/tests/test_results
           cp -r test_results/*.csv workflow/tests/test_results
           cd workflow/tests
-          pip install pandas
+          pip install pandas --break-system-packages
           python ../../hpxml-measures/workflow/tests/merge.py test_results/sample_files1.csv test_results/sample_files2.csv test_results/sample_files.csv
           rm test_results/sample_files1.csv
           rm test_results/sample_files2.csv
@@ -239,10 +239,10 @@ jobs:
           mkdir workflow/tests/test_results
           cp -r test_results/*.csv workflow/tests/test_results
           
-          pip install numpy
-          pip install pandas
-          pip install plotly
-          pip install kaleido
+          pip install numpy --break-system-packages
+          pip install pandas --break-system-packages
+          pip install plotly --break-system-packages
+          pip install kaleido --break-system-packages
           
           python hpxml-measures/workflow/tests/compare.py -a results
           python hpxml-measures/workflow/tests/compare.py -a visualize

Changelog.md

@@ -5,6 +5,10 @@ __New Features__
 - Adds 2024 IECC ERI pathway calculation.
 - **Breaking change**: Renamed `Emissions: <EmissionsType>: RESNET: XXX` to `Emissions: <EmissionsType>: ANSI301: XXX` in Annual Home CSV output files.
 - Adds inputs for modeling skylight curbs and/or shafts.
+- Implements ANSI/RESNET/ICC Standard 301-2022 Addendum E for CFIS systems.
+  - **Breaking change**: Removes `VentilationOnlyModeAirflowFraction` input for CFIS systems (blower fan assumed to run at max flow rate during ventilation only operation).
+  - **Breaking change**: Removes `FanPower`/`FanPowerDefaulted` inputs for CFIS systems (fan power assumed to be HVAC's FanPowerWattsPerCFM multiplied by the blower fan max flow rate).
+  - Allows modeling CFIS systems with no strategy to meet remainder of ventilation target (`CFISControls/AdditionalRuntimeOperatingMode="none"`).
 - Relaxes IECC climate zone requirements.
   - IECC climate zone years other than 2006 are now always optional; for programs that use specific IECC climate zone years (e.g., 2021 for ZERH SF 2.0), that year is used if provided, otherwise the next earliest provided year will be used with the assumption that the climate zone has not changed across the years.
   - See [the documentation](https://openstudio-eri.readthedocs.io/en/latest/workflow_inputs.html#hpxml-climate-zones) for more information.

docs/source/workflow_inputs.rst

@@ -1842,25 +1842,15 @@ Each central fan integrated supply (CFIS) system is entered as a ``/HPXML/Buildi
   ``CFISControls/AdditionalRuntimeOperatingMode``             string                      See [#]_                       Yes                How additional ventilation is provided (beyond when the HVAC system is running)
   ``CFISControls/SupplementalFan``                            idref                       See [#]_                       See [#]_           The supplemental fan providing additional ventilation
   ``AttachedToHVACDistributionSystem``                        idref                       See [#]_                       Yes                ID of attached distribution system
-  ``extension/VentilationOnlyModeAirflowFraction``            double                      >= 0, <= 1                     Yes                Blower airflow rate fraction during ventilation only mode [#]_
   ==========================================================  =================  =======  =============================  ========  =======  =======================================
 
   .. [#] All other UsedFor... elements (i.e., ``UsedForLocalVentilation``, ``UsedForSeasonalCoolingLoadReduction``, ``UsedForGarageVentilation``) must be omitted or false.
-  .. [#] AdditionalRuntimeOperatingMode choices are "air handler fan" or "supplemental fan".
+  .. [#] AdditionalRuntimeOperatingMode choices are "air handler fan", "supplemental fan", or "none".
   .. [#] SupplementalFan must reference another ``VentilationFan`` where UsedForWholeBuildingVentilation=true, IsSharedSystem=false, and FanType="exhaust only" or "supply only".
   .. [#] SupplementalFan only required if AdditionalRuntimeOperatingMode is "supplemental fan".
   .. [#] The flow rate should equal the amount of outdoor air provided to the distribution system, not the total airflow through the distribution system.
   .. [#] The HoursInOperation and the flow rate are combined to form the hourly target ventilation rate (e.g., inputs of 90 cfm and 8 hrs/day produce an hourly target ventilation rate of 30 cfm).
   .. [#] HVACDistribution type cannot be :ref:`hvac_distribution_hydronic`.
-  .. [#] Blower airflow rate when operating in ventilation only mode (i.e., not heating or cooling mode), as a fraction of the maximum blower airflow rate.
-         This value will depend on whether the blower fan can operate at reduced airflow rates during ventilation only operation.
-         It is used to determine how much conditioned air is recirculated through ducts during ventilation only operation, resulting in additional duct losses.
-         A value of zero will result in no conditioned air recirculation, and thus no additional duct losses.
-
-.. note::
-
-  CFIS systems are automated controllers that use the HVAC system's air handler fan to draw in outdoor air to meet an hourly ventilation target.
-  CFIS systems are modeled as assuming they A) maximize the use of normal heating/cooling runtime operation to meet the hourly ventilation target, B) block the flow of outdoor air when the hourly ventilation target has been met, and C) provide additional runtime operation (via air handler fan or supplemental fan) to meet the remainder of the hourly ventilation target when space heating/cooling runtime alone is not sufficient.
 
 .. _vent_fan_shared:
 

hpxml-measures/Changelog.md

@@ -45,6 +45,7 @@ __Bugfixes__
 - Fixes lower element height for a water heater using the advanced `WaterHeatingSystem/extension/TankModelType=stratified`.
 - Fixes possible error for a combi boiler system.
 - Fixes error if modeling a ground-to-air heat pump with a separate backup heating system.
+- Fixes default CFIS fan power during ventilation only mode.
 
 ## OpenStudio-HPXML v1.8.1
 

hpxml-measures/HPXMLtoOpenStudio/measure.xml

@@ -3,8 +3,8 @@
   <schema_version>3.1</schema_version>
   <name>hpxm_lto_openstudio</name>
   <uid>b1543b30-9465-45ff-ba04-1d1f85e763bc</uid>
-  <version_id>dbd88505-b00e-4617-9501-2b6c664db124</version_id>
-  <version_modified>2024-10-13T19:48:28Z</version_modified>
+  <version_id>b5f6daaa-2d62-4c04-8442-5dd880a2a3eb</version_id>
+  <version_modified>2024-10-14T15:59:52Z</version_modified>
   <xml_checksum>D8922A73</xml_checksum>
   <class_name>HPXMLtoOpenStudio</class_name>
   <display_name>HPXML to OpenStudio Translator</display_name>
@@ -189,7 +189,7 @@
       <filename>airflow.rb</filename>
       <filetype>rb</filetype>
       <usage_type>resource</usage_type>
-      <checksum>A1DA58C9</checksum>
+      <checksum>443A48EB</checksum>
     </file>
     <file>
       <filename>battery.rb</filename>
@@ -327,7 +327,7 @@
       <filename>defaults.rb</filename>
       <filetype>rb</filetype>
       <usage_type>resource</usage_type>
-      <checksum>1C554EBA</checksum>
+      <checksum>DF462CB6</checksum>
     </file>
     <file>
       <filename>energyplus.rb</filename>
@@ -357,7 +357,7 @@
       <filename>hpxml.rb</filename>
       <filetype>rb</filetype>
       <usage_type>resource</usage_type>
-      <checksum>75062717</checksum>
+      <checksum>D8F0176E</checksum>
     </file>
     <file>
       <filename>hpxml_schema/HPXML.xsd</filename>
@@ -375,7 +375,7 @@
       <filename>hpxml_schematron/EPvalidator.xml</filename>
       <filetype>xml</filetype>
       <usage_type>resource</usage_type>
-      <checksum>F77D6962</checksum>
+      <checksum>5238EC23</checksum>
     </file>
     <file>
       <filename>hpxml_schematron/iso-schematron.xsd</filename>
@@ -647,17 +647,11 @@
       <usage_type>resource</usage_type>
       <checksum>93120E27</checksum>
     </file>
-    <file>
-      <filename>in.schedules.csv</filename>
-      <filetype>csv</filetype>
-      <usage_type>test</usage_type>
-      <checksum>61EDE63A</checksum>
-    </file>
     <file>
       <filename>test_airflow.rb</filename>
       <filetype>rb</filetype>
       <usage_type>test</usage_type>
-      <checksum>3FC8C8A7</checksum>
+      <checksum>06A02536</checksum>
     </file>
     <file>
       <filename>test_battery.rb</filename>
@@ -669,7 +663,7 @@
       <filename>test_defaults.rb</filename>
       <filetype>rb</filetype>
       <usage_type>test</usage_type>
-      <checksum>DF7D214E</checksum>
+      <checksum>05F155DA</checksum>
     </file>
     <file>
       <filename>test_enclosure.rb</filename>
@@ -741,7 +735,7 @@
       <filename>test_validation.rb</filename>
       <filetype>rb</filetype>
       <usage_type>test</usage_type>
-      <checksum>D7BF36E5</checksum>
+      <checksum>2E4AE571</checksum>
     </file>
     <file>
       <filename>test_water_heater.rb</filename>

hpxml-measures/HPXMLtoOpenStudio/resources/airflow.rb

@@ -1921,7 +1921,6 @@ def self.apply_cfis(runner, infil_program, vent_mech_fans, cfis_data, cfis_fan_a
       fan_data[:rtf_sensor][object].each do |rtf_sensor|
         infil_program.addLine("Set fan_rtf_hvac = fan_rtf_hvac + #{rtf_sensor.name}")
       end
-      infil_program.addLine("Set cfis_fan_w = #{vent_mech.unit_fan_power}") # W
 
       infil_program.addLine('If @ABS(Minute - ZoneTimeStep*60) < 0.1')
       infil_program.addLine("  Set #{cfis_data[:t_sum_open_var][vent_mech.id].name} = 0") # New hour, time on summation re-initializes to 0
@@ -1943,6 +1942,7 @@ def self.apply_cfis(runner, infil_program, vent_mech_fans, cfis_data, cfis_fan_a
       infil_program.addLine("    Set #{cfis_data[:f_damper_extra_open_var][vent_mech.id].name} = @Max (cfis_f_damper_open - fan_rtf_hvac) 0.0")
       if vent_mech.cfis_addtl_runtime_operating_mode == HPXML::CFISModeAirHandler
         # Air handler meets additional runtime requirement
+        infil_program.addLine("Set cfis_fan_w = #{vent_mech.unit_fan_power}") # W
         infil_program.addLine("    Set #{cfis_fan_actuator.name} = #{cfis_fan_actuator.name} + cfis_fan_w * #{cfis_data[:f_damper_extra_open_var][vent_mech.id].name}")
       elsif vent_mech.cfis_addtl_runtime_operating_mode == HPXML::CFISModeSupplementalFan
         if vent_mech.cfis_supplemental_fan.oa_unit_flow_rate < vent_mech.average_unit_flow_rate

hpxml-measures/HPXMLtoOpenStudio/resources/defaults.rb

@@ -96,8 +96,9 @@ def self.apply(runner, hpxml, hpxml_bldg, weather, schedules_file: nil, convert_
     # Do HVAC sizing after all other defaults have been applied
     all_zone_loads, all_space_loads = apply_hvac_sizing(runner, hpxml_bldg, weather)
 
-    # Default detailed performance has to be after sizing to have autosized capacity information
+    # These need to be applied after sizing HVAC capacities/airflows
     apply_detailed_performance_data_for_var_speed_systems(hpxml_bldg)
+    apply_cfis_fan_power(hpxml_bldg)
 
     cleanup_zones_spaces(hpxml_bldg)
 
@@ -2734,21 +2735,21 @@ def self.apply_ventilation_fans(hpxml_bldg, weather, eri_version)
         vent_fan.rated_flow_rate_isdefaulted = true
       end
 
-      if vent_fan.fan_power.nil?
-        fan_w_per_cfm = get_mech_vent_fan_efficiency(vent_fan, eri_version)
-        vent_fan.fan_power = (vent_fan.flow_rate * fan_w_per_cfm).round(1)
+      if vent_fan.fan_power.nil? && vent_fan.fan_type != HPXML::MechVentTypeCFIS # CFIS systems have their fan power defaulted later once we have autosized the total blower fan airflow rate
+        fan_w_per_cfm = get_mech_vent_fan_efficiency(vent_fan)
+        vent_fan.fan_power = (vent_fan.flow_rate * fan_w_per_cfm).round(2)
         vent_fan.fan_power_isdefaulted = true
       end
       next unless vent_fan.fan_type == HPXML::MechVentTypeCFIS
 
-      if vent_fan.cfis_vent_mode_airflow_fraction.nil?
-        vent_fan.cfis_vent_mode_airflow_fraction = 1.0
-        vent_fan.cfis_vent_mode_airflow_fraction_isdefaulted = true
-      end
       if vent_fan.cfis_addtl_runtime_operating_mode.nil?
         vent_fan.cfis_addtl_runtime_operating_mode = HPXML::CFISModeAirHandler
         vent_fan.cfis_addtl_runtime_operating_mode_isdefaulted = true
       end
+      if vent_fan.cfis_vent_mode_airflow_fraction.nil? && (vent_fan.cfis_addtl_runtime_operating_mode == HPXML::CFISModeAirHandler)
+        vent_fan.cfis_vent_mode_airflow_fraction = 1.0
+        vent_fan.cfis_vent_mode_airflow_fraction_isdefaulted = true
+      end
     end
 
     # Default kitchen fan
@@ -2818,6 +2819,40 @@ def self.apply_ventilation_fans(hpxml_bldg, weather, eri_version)
     end
   end
 
+  # Assigns the blower fan power for a CFIS system where the optional input has been omitted.
+  #
+  # @param hpxml_bldg [HPXML::Building] HPXML Building object representing an individual dwelling unit
+  # @return [nil]
+  def self.apply_cfis_fan_power(hpxml_bldg)
+    hpxml_bldg.ventilation_fans.each do |vent_fan|
+      next unless vent_fan.used_for_whole_building_ventilation
+      next unless vent_fan.fan_type == HPXML::MechVentTypeCFIS
+      next unless vent_fan.cfis_addtl_runtime_operating_mode == HPXML::CFISModeAirHandler
+      next unless vent_fan.fan_power.nil?
+
+      hvac_systems = vent_fan.distribution_system.hvac_systems
+      fan_w_per_cfm = hvac_systems[0].fan_watts_per_cfm
+
+      # Get max blower airflow rate
+      blower_flow_rate = nil
+      hvac_systems.each do |hvac_system|
+        if hvac_system.respond_to?(:heating_airflow_cfm) && hvac_system.heating_airflow_cfm > blower_flow_rate.to_f
+          blower_flow_rate = hvac_system.heating_airflow_cfm
+        end
+        if hvac_system.respond_to?(:cooling_airflow_cfm) && hvac_system.cooling_airflow_cfm > blower_flow_rate.to_f
+          blower_flow_rate = hvac_system.cooling_airflow_cfm
+        end
+      end
+      fail 'Unexpected error.' if blower_flow_rate.to_f == 0
+
+      # Calculate blower airflow rate in vent only mode
+      blower_flow_rate *= vent_fan.cfis_vent_mode_airflow_fraction
+
+      vent_fan.fan_power = (blower_flow_rate * fan_w_per_cfm).round(2)
+      vent_fan.fan_power_isdefaulted = true
+    end
+  end
+
   # Assigns default values for omitted optional inputs in the HPXML::WaterHeatingSystem objects
   #
   # @param hpxml_bldg [HPXML::Building] HPXML Building object representing an individual dwelling unit
@@ -4664,9 +4699,8 @@ def self.get_mech_vent_flow_rate_for_vent_fan(hpxml_bldg, vent_fan, weather, eri
   # Gets the default whole-home mechanical ventilation fan efficiency.
   #
   # @param vent_fan [HPXML::VentilationFan] The HPXML ventilation fan of interest
-  # @param eri_version [String] Version of the ANSI/RESNET/ICC 301 Standard to use for equations/assumptions
   # @return [Double] Fan efficiency (W/cfm)
-  def self.get_mech_vent_fan_efficiency(vent_fan, eri_version)
+  def self.get_mech_vent_fan_efficiency(vent_fan)
     # Returns fan power in W/cfm, based on ANSI 301
     if vent_fan.is_shared_system
       return 1.00 # Table 4.2.2(1) Note (n)
@@ -4676,12 +4710,6 @@ def self.get_mech_vent_fan_efficiency(vent_fan, eri_version)
       return 0.70
     elsif [HPXML::MechVentTypeERV, HPXML::MechVentTypeHRV].include? vent_fan.fan_type
       return 1.00
-    elsif [HPXML::MechVentTypeCFIS].include? vent_fan.fan_type
-      if Constants::ERIVersions.index(eri_version) >= Constants::ERIVersions.index('2022')
-        return 0.58
-      else
-        return 0.50
-      end
     else
       fail "Unexpected fan_type: '#{fan_type}'."
     end

hpxml-measures/HPXMLtoOpenStudio/resources/hpxml.rb

@@ -8211,6 +8211,11 @@ def is_cfis_supplemental_fan
     #
     # @return [nil]
     def delete
+      if is_cfis_supplemental_fan
+        @parent_object.ventilation_fans.each do |vent_fan|
+          vent_fan.cfis_supplemental_fan_idref = nil if vent_fan.cfis_supplemental_fan_idref == @id
+        end
+      end
       @parent_object.ventilation_fans.delete(self)
     end