HP lockout temps

Changelog.md

@@ -5,9 +5,10 @@ __New Features__
 - Updates to HPXML v5.0-rc1.
   - **Breaking change**: HPXML namespace changed from http://hpxmlonline.com/2023/09 to http://hpxmlonline.com/2025/12.
 - Updated DX heat pump and air conditioner models per HERS Addendum 103.
+  - Compressor lockout temperatures for Rated Home defaults and Reference Home updated from 0F (single/two stage) and -20F (variable speed) to 5F and -10F, respectively.
   - Dual-fuel heat pumps now have the HP sized using the greater of the heating design temperature and 25F.
   - Pan heaters no longer operate when the outdoor temperature is below the compressor lockout temperature.
-- The `NominalCapacity` input for batteries is no longer used.
+- The `Battery/NominalCapacity` input is no longer used.
 
 ## OpenStudio-ERI v1.11.2
 

docs/source/workflow_inputs.rst

@@ -1324,7 +1324,7 @@ Each air-to-air heat pump is entered as a ``/HPXML/Building/BuildingDetails/Syst
   .. [#] HeatingCapacity=-1 and CoolingCapacity=-1 can be used to autosize the equipment for research purposes or to run tests (it should *not* be used for a real home).
   .. [#] CompressorType choices are "single stage", "two stage", or "variable speed".
   .. [#] CompressorLockoutTemperature input is only allowed if ``BackupSystemFuel`` is "electricity" or not provided (i.e., it is not allowed for dual-fuel heat pumps).
-         If not provided, CompressorLockoutTemperature defaults to -20F if CompressorType is "variable speed" otherwise 0F.
+         If not provided, CompressorLockoutTemperature defaults to -10F if CompressorType is "variable speed" otherwise 5F.
   .. [#] Additional backup inputs are described in :ref:`hvac_hp_backup`.
   .. [#] The sum of all ``FractionHeatLoadServed`` (across all HVAC systems) must be less than or equal to 1.
   .. [#] The sum of all ``FractionCoolLoadServed`` (across all HVAC systems) must be less than or equal to 1.
@@ -1391,7 +1391,7 @@ Each ``HeatPump`` should represent a single outdoor unit, whether connected to o
   .. [#] If DistributionSystem provided, HVACDistribution type must be :ref:`hvac_distribution_air` (type: "regular velocity") or :ref:`hvac_distribution_dse`.
   .. [#] HeatingCapacity=-1 and CoolingCapacity=-1 can be used to autosize the equipment for research purposes or to run tests (it should *not* be used for a real home).
   .. [#] CompressorLockoutTemperature input is only allowed if ``BackupSystemFuel`` is "electricity" or not provided (i.e., it is not allowed for dual-fuel heat pumps).
-         If not provided, CompressorLockoutTemperature defaults to -20F.
+         If not provided, CompressorLockoutTemperature defaults to -10F.
   .. [#] Additional backup inputs are described in :ref:`hvac_hp_backup`.
   .. [#] The sum of all ``FractionHeatLoadServed`` (across all HVAC systems) must be less than or equal to 1.
   .. [#] The sum of all ``FractionCoolLoadServed`` (across all HVAC systems) must be less than or equal to 1.
@@ -1445,7 +1445,7 @@ Each packaged terminal heat pump is entered as a ``/HPXML/Building/BuildingDetai
 
   .. [#] HeatingCapacity=-1 and CoolingCapacity=-1 can be used to autosize the equipment for research purposes or to run tests (it should *not* be used for a real home).
   .. [#] CompressorLockoutTemperature input is only allowed if ``BackupSystemFuel`` is "electricity" or not provided (i.e., it is not allowed for dual-fuel heat pumps).
-         If not provided, CompressorLockoutTemperature defaults to 0F.
+         If not provided, CompressorLockoutTemperature defaults to 5F.
   .. [#] Additional backup inputs are described in :ref:`hvac_hp_backup`.
   .. [#] The sum of all ``FractionHeatLoadServed`` (across all HVAC systems) must be less than or equal to 1.
   .. [#] The sum of all ``FractionCoolLoadServed`` (across all HVAC systems) must be less than or equal to 1.
@@ -1476,7 +1476,7 @@ Each room air conditioner with reverse cycle is entered as a ``/HPXML/Building/B
 
   .. [#] HeatingCapacity=-1 and CoolingCapacity=-1 can be used to autosize the equipment for research purposes or to run tests (it should *not* be used for a real home).
   .. [#] CompressorLockoutTemperature input is only allowed if ``BackupSystemFuel`` is "electricity" or not provided (i.e., it is not allowed for dual-fuel heat pumps).
-         If not provided, CompressorLockoutTemperature defaults to 0F.
+         If not provided, CompressorLockoutTemperature defaults to 5F.
   .. [#] Additional backup inputs are described in :ref:`hvac_hp_backup`.
   .. [#] The sum of all ``FractionHeatLoadServed`` (across all HVAC systems) must be less than or equal to 1.
   .. [#] The sum of all ``FractionCoolLoadServed`` (across all HVAC systems) must be less than or equal to 1.

rulesets/resources/301ruleset.rb

@@ -3174,12 +3174,12 @@ def self.get_hp_compressor_lockout_temp(heat_pump_type, backup_heating_fuel, com
 
       # No user input, default
       if compressor_type == HPXML::HVACCompressorTypeVariableSpeed
-        return -20.0 # F
+        return -10.0 # F, Addendum 103 AC/HP Supplement
       else
-        return 0.0 # F
+        return 5.0 # F, Addendum 103 AC/HP Supplement
       end
     else # Fossil fuel
-      # Use RESNET prescribed value
+      # Always use RESNET prescribed value
       return 40.0 # F
     end
   end