Class: OpenStudio::Model::AirTerminalSingleDuctParallelPIUReheat

Inherits:
Object
  • Object
show all
Defined in:
lib/openstudio-standards/hvac_sizing/HVACSizing.AirTerminalSingleDuctParallelPIUReheat.rb,
lib/openstudio-standards/standards/Standards.AirTerminalSingleDuctParallelPIUReheat.rb

Overview

open the class to add methods to apply HVAC efficiency standards

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/HVACSizing.AirTerminalSingleDuctParallelPIUReheat.rb', line 13

def applySizingValues

  maximum_primary_air_flow_rate = self.autosizedMaximumPrimaryAirFlowRate
  if maximum_primary_air_flow_rate.is_initialized
    self.setMaximumPrimaryAirFlowRate(maximum_primary_air_flow_rate.get) 
  end
  
  maximum_secondary_air_flow_rate = self.autosizedMaximumSecondaryAirFlowRate
  if maximum_secondary_air_flow_rate.is_initialized
    self.setMaximumSecondaryAirFlowRate(maximum_secondary_air_flow_rate.get)
  end
  
  minimum_primary_air_flow_fraction = self.autosizedMinimumPrimaryAirFlowFraction
  if minimum_primary_air_flow_fraction.is_initialized
    self.setMinimumPrimaryAirFlowFraction(minimum_primary_air_flow_fraction.get) 
  end
  
  fan_on_flow_fraction = self.autosizedFanOnFlowFraction
  if fan_on_flow_fraction.is_initialized
    self.setFanOnFlowFraction(fan_on_flow_fraction.get)
  end

  
end

#autosize ⇒ Object

Sets all auto-sizeable fields to autosize



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# File 'lib/openstudio-standards/hvac_sizing/HVACSizing.AirTerminalSingleDuctParallelPIUReheat.rb', line 6

def autosize
  OpenStudio::logFree(OpenStudio::Warn, "openstudio.sizing.AirTerminalSingleDuctParallelPIUReheat", ".autosize not yet implemented for #{self.iddObject.type.valueDescription}.")
end

#autosizedFanOnFlowFraction ⇒ Object

returns the autosized fan on flow fraction as an optional double



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# File 'lib/openstudio-standards/hvac_sizing/HVACSizing.AirTerminalSingleDuctParallelPIUReheat.rb', line 60

def autosizedFanOnFlowFraction

  return self.model.getAutosizedValue(self, 'Design Size Fan On Flow Fraction', '')
     
end

#autosizedMaximumPrimaryAirFlowRate ⇒ Object

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



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# File 'lib/openstudio-standards/hvac_sizing/HVACSizing.AirTerminalSingleDuctParallelPIUReheat.rb', line 39

def autosizedMaximumPrimaryAirFlowRate

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

#autosizedMaximumSecondaryAirFlowRate ⇒ Object

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



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# File 'lib/openstudio-standards/hvac_sizing/HVACSizing.AirTerminalSingleDuctParallelPIUReheat.rb', line 46

def autosizedMaximumSecondaryAirFlowRate

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

#autosizedMinimumPrimaryAirFlowFraction ⇒ Object

returns the autosized minimum primary air flow fraction as an optional double



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# File 'lib/openstudio-standards/hvac_sizing/HVACSizing.AirTerminalSingleDuctParallelPIUReheat.rb', line 53

def autosizedMinimumPrimaryAirFlowFraction

  return self.model.getAutosizedValue(self, 'Design Size Minimum Primary Air Flow Fraction', '')
    
end

#set_performance_rating_method_baseline_fan_power(template) ⇒ Bool

Sets the fan power of a PIU fan based on the W/cfm specified in the standard.

Parameters:

  • template (String) —

    the standard

Returns:

  • (Bool) —

    returns true if successful, false if not



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# File 'lib/openstudio-standards/standards/Standards.AirTerminalSingleDuctParallelPIUReheat.rb', line 10

def set_performance_rating_method_baseline_fan_power(template)

  OpenStudio::logFree(OpenStudio::Debug, 'openstudio.model.AirTerminalSingleDuctParallelPIUReheat', "Setting PIU fan power for #{self.name}.")
  
  # Determine the fan sizing flow rate, min flow rate,
  # and W/cfm
  sec_flow_frac = 0.5
  min_flow_frac = 0.3
  fan_efficacy_w_per_cfm = 0.35
  # case template
  # when
  # else
  # end
  
  # Get the maximum flow rate through the terminal
  max_primary_air_flow_rate = nil
  if self.autosizedMaximumPrimaryAirFlowRate.is_initialized
    max_primary_air_flow_rate = self.autosizedMaximumPrimaryAirFlowRate.get
  elsif self.maximumPrimaryAirFlowRate.is_initialized
    max_primary_air_flow_rate = self.maximumPrimaryAirFlowRate.get
  end
  
  # Set the max secondary air flow rate
  max_sec_flow_rate_m3_per_s = max_primary_air_flow_rate * sec_flow_frac
  self.setMaximumSecondaryAirFlowRate(max_sec_flow_rate_m3_per_s)
  
  # Set the minimum flow fraction
  #TODO Also compare to min OA requirement
  self.setMinimumPrimaryAirFlowFraction(min_flow_frac)

  # Set the fan efficacy
  fan = self.fan.to_FanConstantVolume.get
  fan_rise_pa = fan.pressureRise
  fan_rise_in_wc = OpenStudio.convert(fan_rise_pa, "Pa", "inH_{2}O")
  OpenStudio::logFree(OpenStudio::Debug, 'openstudio.model.AirTerminalSingleDuctParallelPIUReheat', "=> Pressure Rise = #{fan_rise_pa} Pa")

  max_sec_flow_rate_cfm = OpenStudio.convert(max_sec_flow_rate_m3_per_s, "m^3/s", "ft^3/min").get
  OpenStudio::logFree(OpenStudio::Debug, 'openstudio.model.AirTerminalSingleDuctParallelPIUReheat', "=> Maximum Fan Flow Rate = #{max_sec_flow_rate_cfm} m3/s")
  OpenStudio::logFree(OpenStudio::Debug, 'openstudio.model.AirTerminalSingleDuctParallelPIUReheat', "=> Maximum Secondary Air Flow Rate = #{self.maximumSecondaryAirFlowRate.get} m3/s")      
  
  fan_efficiency = fan.fanEfficiency
  OpenStudio::logFree(OpenStudio::Debug, 'openstudio.model.AirTerminalSingleDuctParallelPIUReheat', "=> Fan Total Efficiency = #{fan_efficiency}")

  fan_power_w = fan_rise_pa * max_sec_flow_rate_m3_per_s / fan_efficiency
  fan_efficacy_calc = fan_power_w / max_sec_flow_rate_m3_per_s
  OpenStudio::logFree(OpenStudio::Debug, 'openstudio.model.AirTerminalSingleDuctParallelPIUReheat', "=> fan efficacy calculated = #{fan_efficacy_calc} W-s/m3")

  fan_efficacy_w_per_m3_per_s = fan_efficacy_w_per_cfm * OpenStudio.convert(1, 'm^3/s', 'cfm').get

  fan_rise_new_pa = fan_efficacy_w_per_m3_per_s * fan_efficiency
  OpenStudio::logFree(OpenStudio::Debug, 'openstudio.model.AirTerminalSingleDuctParallelPIUReheat', "=> fan pressure rise new = #{fan_rise_new_pa} Pa")
  fan.setPressureRise(fan_rise_new_pa)
  fan_power_new_w = fan_rise_new_pa * max_sec_flow_rate_cfm / fan_efficiency
  fan_efficacy_new_w_per_cfm = fan_power_new_w / max_sec_flow_rate_cfm
  
  OpenStudio::logFree(OpenStudio::Debug, 'openstudio.model.AirTerminalSingleDuctParallelPIUReheat', "For #{self.name}: fan efficacy set to #{fan_efficacy_new_w_per_cfm.round(2)} W/cfm, fan bhp = #{fan.brakeHorsepower} hp, motor efficiency = #{fan.motorEfficiency}.")
  
  return true

end