Class: OpenStudio::Model::ControllerOutdoorAir

Inherits:
Object
  • Object
show all
Defined in:
lib/openstudio-standards/hvac_sizing/Siz.ControllerOutdoorAir.rb

Overview

open the class to add methods to return sizing values

Instance Method Summary collapse

Instance Method Details

#applySizingValues ⇒ Object

Takes the values calculated by the EnergyPlus sizing routines and puts them into this object model in place of the autosized fields. Must have previously completed a run with sql output for this to work.



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# File 'lib/openstudio-standards/hvac_sizing/Siz.ControllerOutdoorAir.rb', line 14

def applySizingValues

  maximum_outdoor_air_flow_rate = self.autosizedMaximumOutdoorAirFlowRate
  if maximum_outdoor_air_flow_rate.is_initialized
    self.setMaximumOutdoorAirFlowRate(maximum_outdoor_air_flow_rate.get) 
  end

  minimum_outdoor_air_flow_rate = self.autosizedMinimumOutdoorAirFlowRate
  if minimum_outdoor_air_flow_rate.is_initialized
    self.setMinimumOutdoorAirFlowRate(minimum_outdoor_air_flow_rate.get) 
  end
  
end

#autosize ⇒ Object

Sets all auto-sizeable fields to autosize



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# File 'lib/openstudio-standards/hvac_sizing/Siz.ControllerOutdoorAir.rb', line 6

def autosize
  self.autosizeMaximumOutdoorAirFlowRate
  self.autosizeMinimumOutdoorAirFlowRate
end

#autosizedMaximumOutdoorAirFlowRate ⇒ Object

returns the autosized maximum outdoor air flow rate as an optional double



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# File 'lib/openstudio-standards/hvac_sizing/Siz.ControllerOutdoorAir.rb', line 29

def autosizedMaximumOutdoorAirFlowRate

  return self.model.getAutosizedValue(self, 'Maximum Outdoor Air Flow Rate', 'm3/s')
  
end

#autosizedMinimumOutdoorAirFlowRate ⇒ Object

TODO:

determine what to do when the airloop has multiple zones

returns the autosized minimum outdoor air flow rate as an optional double EnergyPlus has a “bug” where if the system is a multizone system, the Minimum Outdoor Air Flow Rate reported in the Component Sizing summary does not include zone multipliers. with different multipliers



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# File 'lib/openstudio-standards/hvac_sizing/Siz.ControllerOutdoorAir.rb', line 41

def autosizedMinimumOutdoorAirFlowRate

  oa = self.model.getAutosizedValue(self, 'Minimum Outdoor Air Flow Rate', 'm3/s')

  # Get the airloop connected to this controller
  if airLoopHVACOutdoorAirSystem.empty?
    OpenStudio.logFree(OpenStudio::Warn, 'openstudio.Siz.ControllerOutdoorAir', "#{name} is not connected to an airLoopHVACOutdoorAirSystem, cannot determine autosizedMinimumOutdoorAirFlowRate accuractely.")
    return oa
  end
  oa_sys = airLoopHVACOutdoorAirSystem.get
  if oa_sys.airLoop.empty?
    OpenStudio.logFree(OpenStudio::Warn, 'openstudio.Siz.ControllerOutdoorAir', "#{name}'s airLoopHVACOutdoorAirSystem is not assigned to an AirLoop, cannot determine autosizedMinimumOutdoorAirFlowRate accuractely.")
    return oa
  end
  air_loop = oa_sys.airLoop.get

  # Determine if the system is multizone
  multizone = false
  if air_loop.thermalZones.size > 1
    multizone = true
  end

  # Determine if the system is variable volume
  vav = false
  air_loop.supplyComponents.reverse.each do |comp|
    if comp.to_FanVariableVolume.is_initialized
      vav = true
    elsif comp.to_AirLoopHVACUnitaryHeatCoolVAVChangeoverBypass.is_initialized
      fan = comp.to_AirLoopHVACUnitaryHeatCoolVAVChangeoverBypass.get.supplyAirFan
      if fan.to_FanVariableVolume.is_initialized
        vav = true
      end
    elsif comp.to_AirLoopHVACUnitarySystem.is_initialized
      fan = comp.to_AirLoopHVACUnitarySystem.get.supplyFan
      if fan.is_initialized
        if fan.get.to_FanVariableVolume.is_initialized
          vav = true
        end
      end
    end
  end
  
  # If it is a multizone VAV system, get the system multiplier
  # to work around the bug in EnergyPlus.
  if multizone && vav
    if oa.is_initialized
      oa_val = oa.get
      
      # Get the system multiplier
      mult = 1

      # Get all the zone multipliers
      zn_mults = []
      air_loop.thermalZones.each do |zone|
        zn_mults << zone.multiplier
      end
   
      # Warn if there are different multipliers
      uniq_mults = zn_mults.uniq
      if uniq_mults.size > 1
        OpenStudio.logFree(OpenStudio::Warn, 'openstudio.standards.AirLoopHVAC', "For #{air_loop.name}: not all zones on the system have an identical zone multiplier.  Multipliers are: #{uniq_mults.join(', ')}.")
      else
        mult = uniq_mults[0]
      end

      oa_val = oa_val * mult
      oa = OpenStudio::OptionalDouble.new(oa_val)
    end
  end

  return oa
end