class ASHRAE9012019

This class holds methods that apply ASHRAE 90.1-2019 to a given model. @ref [References::ASHRAE9012019]

Attributes

template[R]

Public Class Methods

new() click to toggle source
# File lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.rb, line 8
def initialize
  @template = '90.1-2019'
  load_standards_database
end

Public Instance Methods

air_loop_hvac_adjust_minimum_vav_damper_positions(air_loop_hvac) click to toggle source

Adjust minimum VAV damper positions and set minimum design system outdoor air flow following ASHRAE Std. 62.1-2019

@param (see economizer_required?) @return [Boolean] Returns true if required, false if not. @todo Add exception logic for systems serving parking garage, warehouse, or multifamily

# File lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.AirLoopHVAC.rb, line 562
  def air_loop_hvac_adjust_minimum_vav_damper_positions(air_loop_hvac)
    # Do not apply the adjustment to some of the system in
    # the hospital and outpatient which have their minimum
    # damper position determined based on AIA 2001 ventilation
    # requirements
    if (@instvarbuilding_type == 'Hospital' && (air_loop_hvac.name.to_s.include?('VAV_ER') || air_loop_hvac.name.to_s.include?('VAV_ICU') ||
                                                air_loop_hvac.name.to_s.include?('VAV_OR') || air_loop_hvac.name.to_s.include?('VAV_LABS') ||
                                                air_loop_hvac.name.to_s.include?('VAV_PATRMS'))) ||
       (@instvarbuilding_type == 'Outpatient' && air_loop_hvac.name.to_s.include?('Outpatient F1'))

      return true
    end

    # Total uncorrected outdoor airflow rate
    v_ou = 0.0
    air_loop_hvac.thermalZones.each do |zone|
      # Vou is the system uncorrected outdoor airflow:
      # Zone airflow is multiplied by the zone multiplier
      v_ou += OpenstudioStandards::ThermalZone.thermal_zone_get_outdoor_airflow_rate(zone) * zone.multiplier.to_f
    end

    v_ou_cfm = OpenStudio.convert(v_ou, 'm^3/s', 'cfm').get

    OpenStudio.logFree(OpenStudio::Debug, 'openstudio.standards.AirLoopHVAC', "For #{air_loop_hvac.name}: v_ou = #{v_ou_cfm.round} cfm.")

    # Retrieve the sum of the zone minimum primary airflow
    if air_loop_hvac.model.version < OpenStudio::VersionString.new('3.6.0')
      OpenStudio.logFree(OpenStudio::Error, 'openstudio.ashrae_90_1_2019.AirLoopHVAC', 'Required AirLoopHVAC method .autosizedSumMinimumHeatingAirFlowRates is not available in pre-OpenStudio 3.6.0 versions. Use a more recent version of OpenStudio.')
    else
      vpz_min_sum = air_loop_hvac.autosizedSumMinimumHeatingAirFlowRates
    end

    air_loop_hvac.thermalZones.sort.each do |zone|
      # Breathing zone airflow rate
      v_bz = OpenstudioStandards::ThermalZone.thermal_zone_get_outdoor_airflow_rate(zone)

      # Zone air distribution, assumed 1 per PNNL
      e_z = 1.0

      # Zone airflow rate
      v_oz = v_bz / e_z

      # Primary design airflow rate
      # max of heating and cooling
      # design air flow rates
      v_pz = 0.0

      # error if zone autosized methods are not available
      if air_loop_hvac.model.version < OpenStudio::VersionString.new('3.6.0')
        OpenStudio.logFree(OpenStudio::Error, 'openstudio.ashrae_90_1_2019.AirLoopHVAC', 'Required ThermalZone methods .autosizedCoolingDesignAirFlowRate and .autosizedHeatingDesignAirFlowRate are not available in pre-OpenStudio 3.6.0 versions. Use a more recent version of OpenStudio.')
      end

      clg_dsn_flow = zone.autosizedCoolingDesignAirFlowRate
      if clg_dsn_flow.is_initialized
        clg_dsn_flow = clg_dsn_flow.get
        if clg_dsn_flow > v_pz
          v_pz = clg_dsn_flow
        end
      else
        OpenStudio.logFree(OpenStudio::Warn, 'openstudio.ashrae_90_1_2019.AirLoopHVAC', "For #{air_loop_hvac.name}: #{zone.name} clg_dsn_flow could not be found.")
      end
      htg_dsn_flow = zone.autosizedHeatingDesignAirFlowRate
      if htg_dsn_flow.is_initialized
        htg_dsn_flow = htg_dsn_flow.get
        if htg_dsn_flow > v_pz
          v_pz = htg_dsn_flow
        end
      else
        OpenStudio.logFree(OpenStudio::Warn, 'openstudio.ashrae_90_1_2019.AirLoopHVAC', "For #{air_loop_hvac.name}: #{zone.name} htg_dsn_flow could not be found.")
      end

      # Zone ventilation efficiency calculation is computed
      # on a per zone basis, the zone primary airflow is
      # adjusted to removed the zone multiplier
      v_pz /= zone.multiplier.to_f

      # Set minimum damper position
      air_loop_hvac_set_minimum_damper_position(zone, [0.01, [1.5 * v_oz / v_pz, 1.0].min].max.round(3))
    end

    # Occupant diversity (D): Ps / sum(Pz)
    # Current value is based on school prototypes
    # which are assumed to have the most diversity
    occ_diver_d = 0.66

    # From ASHRAE Std 62.1-2019 Section 6.2.5.3
    if occ_diver_d < 0.6
      e_v = 0.88 * occ_diver_d + 0.22
    else
      e_v = 0.75
    end

    # Total system outdoor intake flow rate
    v_ot = v_ou / e_v
    v_ot_cfm = OpenStudio.convert(v_ot, 'm^3/s', 'cfm').get

    # Get maximum OA fraction schedule
    oa_ctrl = air_loop_hvac.airLoopHVACOutdoorAirSystem.get.getControllerOutdoorAir
    max_oa_frac_sch = oa_ctrl.maximumFractionofOutdoorAirSchedule

    if !max_oa_frac_sch.is_initialized
      max_oa_frac_sch = OpenStudio::Model::ScheduleConstant.new(air_loop_hvac.model)
      max_oa_frac_sch.setName("#{air_loop_hvac.name}_MAX_OA_FRAC")
      max_oa_frac_sch.setValue(1.0)
      max_oa_frac_sch_type = 'Schedule:Constant'
      oa_ctrl.setMaximumFractionofOutdoorAirSchedule(max_oa_frac_sch)
    else
      max_oa_frac_sch = max_oa_frac_sch.get
      if max_oa_frac_sch.to_ScheduleRuleset.is_initialized
        max_oa_frac_sch = max_oa_frac_sch.to_ScheduleRuleset.get
        max_oa_frac_sch_type = 'Schedule:Year'
      elsif max_oa_frac_sch.to_ScheduleConstant.is_initialized
        max_oa_frac_sch = max_oa_frac_sch.to_ScheduleConstant.get
        max_oa_frac_sch_type = 'Schedule:Constant'
      elsif max_oa_frac_sch.to_ScheduleCompact.is_initialized
        max_oa_frac_sch = max_oa_frac_sch.to_ScheduleCompact.get
        max_oa_frac_sch_type = 'Schedule:Compact'
      end
    end

    # Add EMS to "cap" the OA calculated by the
    # Controller:MechanicalVentilation object
    # to the design v_ot using the maximum OA
    # fraction schedule
    # In newer EnergyPlus versions, this is handled by Standard62.1VentilationRateProcedureWithLimit
    # in the Controller:MechanicalVentilation object
    if air_loop_hvac.model.version < OpenStudio::VersionString.new('3.3.0')
      # Add EMS sensors
      # OA mass flow calculated by the Controller:MechanicalVentilation
      air_loop_hvac_name_ems = "EMS_#{air_loop_hvac.name.to_s.gsub(' ', '_')}"
      oa_vrp_mass_flow = OpenStudio::Model::EnergyManagementSystemSensor.new(air_loop_hvac.model, 'Air System Outdoor Air Mechanical Ventilation Requested Mass Flow Rate')
      oa_vrp_mass_flow.setKeyName(air_loop_hvac.name.to_s)
      oa_vrp_mass_flow.setName("#{air_loop_hvac_name_ems}_OA_VRP")
      # Actual sensed OA mass flow
      oa_mass_flow = OpenStudio::Model::EnergyManagementSystemSensor.new(air_loop_hvac.model, 'Air System Outdoor Air Mass Flow Rate')
      oa_mass_flow.setKeyName(air_loop_hvac.name.to_s)
      oa_mass_flow.setName("#{air_loop_hvac_name_ems}_OA")
      # Actual sensed volumetric OA flow
      oa_vol_flow = OpenStudio::Model::EnergyManagementSystemSensor.new(air_loop_hvac.model, 'System Node Standard Density Volume Flow Rate')
      oa_vol_flow.setKeyName("#{air_loop_hvac.name} Mixed Air Node")
      oa_vol_flow.setName("#{air_loop_hvac_name_ems}_SUPPLY_FLOW")

      # Add EMS actuator
      max_oa_fraction = OpenStudio::Model::EnergyManagementSystemActuator.new(max_oa_frac_sch, max_oa_frac_sch_type, 'Schedule Value')
      max_oa_fraction.setName("#{air_loop_hvac_name_ems}_MAX_OA_FRAC")

      # Add EMS program
      max_oa_ems_prog = OpenStudio::Model::EnergyManagementSystemProgram.new(air_loop_hvac.model)
      max_oa_ems_prog.setName("#{air_loop_hvac.name}_MAX_OA_FRAC")
      max_oa_ems_prog_body = <<-EMS
      IF #{air_loop_hvac_name_ems}_OA > #{air_loop_hvac_name_ems}_OA_VRP,
      SET #{air_loop_hvac_name_ems}_MAX_OA_FRAC = NULL,
      ELSE,
      IF #{air_loop_hvac_name_ems}_SUPPLY_FLOW > 0,
      SET #{air_loop_hvac_name_ems}_MAX_OA_FRAC = #{v_ot} / #{air_loop_hvac_name_ems}_SUPPLY_FLOW,
      ELSE,
      SET #{air_loop_hvac_name_ems}_MAX_OA_FRAC = NULL,
      ENDIF,
      ENDIF
      EMS
      max_oa_ems_prog.setBody(max_oa_ems_prog_body)

      max_oa_ems_prog_manager = OpenStudio::Model::EnergyManagementSystemProgramCallingManager.new(air_loop_hvac.model)
      max_oa_ems_prog_manager.setName("SET_#{air_loop_hvac.name.to_s.gsub(' ', '_')}_MAX_OA_FRAC")
      max_oa_ems_prog_manager.setCallingPoint('InsideHVACSystemIterationLoop')
      max_oa_ems_prog_manager.addProgram(max_oa_ems_prog)
    end

    # Hard-size the sizing:system
    # object with the calculated min OA flow rate
    sizing_system = air_loop_hvac.sizingSystem
    sizing_system.setDesignOutdoorAirFlowRate(v_ot)
    sizing_system.setSystemOutdoorAirMethod('ZoneSum')

    return true
  end
air_loop_hvac_demand_control_ventilation_limits(air_loop_hvac) click to toggle source

Determines the OA flow rates above which an economizer is required. Two separate rates, one for systems with an economizer and another for systems without.

@param air_loop_hvac [OpenStudio::Model::AirLoopHVAC] air loop @return [Array<Double>] [min_oa_without_economizer_cfm, min_oa_with_economizer_cfm]

# File lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.AirLoopHVAC.rb, line 264
def air_loop_hvac_demand_control_ventilation_limits(air_loop_hvac)
  min_oa_without_economizer_cfm = 3000
  min_oa_with_economizer_cfm = 750
  return [min_oa_without_economizer_cfm, min_oa_with_economizer_cfm]
end
air_loop_hvac_economizer_limits(air_loop_hvac, climate_zone) click to toggle source

Determine the limits for the type of economizer present on the AirLoopHVAC, if any.

@param air_loop_hvac [OpenStudio::Model::AirLoopHVAC] air loop @param climate_zone [String] ASHRAE climate zone, e.g. ‘ASHRAE 169-2013-4A’ @return [Array<Double>] [drybulb_limit_f, enthalpy_limit_btu_per_lb, dewpoint_limit_f]

# File lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.AirLoopHVAC.rb, line 41
def air_loop_hvac_economizer_limits(air_loop_hvac, climate_zone)
  drybulb_limit_f = nil
  enthalpy_limit_btu_per_lb = nil
  dewpoint_limit_f = nil

  # Get the OA system and OA controller
  oa_sys = air_loop_hvac.airLoopHVACOutdoorAirSystem
  return [nil, nil, nil] unless oa_sys.is_initialized

  oa_sys = oa_sys.get
  oa_control = oa_sys.getControllerOutdoorAir
  economizer_type = oa_control.getEconomizerControlType
  oa_control.resetEconomizerMinimumLimitDryBulbTemperature

  case economizer_type
  when 'NoEconomizer'
    OpenStudio.logFree(OpenStudio::Debug, 'openstudio.standards.AirLoopHVAC', "For #{air_loop_hvac.name} no economizer")
    return [nil, nil, nil]
  when 'FixedDryBulb'
    search_criteria = {
      'template' => template,
      'climate_zone' => climate_zone
    }
    econ_limits = model_find_object(standards_data['economizers'], search_criteria)
    drybulb_limit_f = econ_limits['fixed_dry_bulb_high_limit_shutoff_temp']
  when 'FixedEnthalpy'
    enthalpy_limit_btu_per_lb = 28.0
  when 'FixedDewPointAndDryBulb'
    drybulb_limit_f = 75.0
    dewpoint_limit_f = 55.0
  when 'DifferentialDryBulb', 'DifferentialEnthalpy'
    OpenStudio.logFree(OpenStudio::Debug, 'openstudio.standards.AirLoopHVAC', "For #{air_loop_hvac.name}: Economizer type = #{economizer_type}, no limits defined.")
  end

  OpenStudio.logFree(OpenStudio::Info, 'openstudio.standards.AirLoopHVAC', "For #{air_loop_hvac.name}: Economizer type = #{economizer_type}, limits [#{drybulb_limit_f},#{enthalpy_limit_btu_per_lb},#{dewpoint_limit_f}]")

  return [drybulb_limit_f, enthalpy_limit_btu_per_lb, dewpoint_limit_f]
end
air_loop_hvac_economizer_type_allowable?(air_loop_hvac, climate_zone) click to toggle source

Check the economizer type currently specified in the ControllerOutdoorAir object on this air loop is acceptable per the standard.

@param air_loop_hvac [OpenStudio::Model::AirLoopHVAC] air loop @param climate_zone [String] ASHRAE climate zone, e.g. ‘ASHRAE 169-2013-4A’ @return [Boolean] Returns true if allowable, if the system has no economizer or no OA system.

Returns false if the economizer type is not allowable.
# File lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.AirLoopHVAC.rb, line 97
def air_loop_hvac_economizer_type_allowable?(air_loop_hvac, climate_zone)
  # EnergyPlus economizer types
  # 'NoEconomizer'
  # 'FixedDryBulb'
  # 'FixedEnthalpy'
  # 'DifferentialDryBulb'
  # 'DifferentialEnthalpy'
  # 'FixedDewPointAndDryBulb'
  # 'ElectronicEnthalpy'
  # 'DifferentialDryBulbAndEnthalpy'

  # Get the OA system and OA controller
  oa_sys = air_loop_hvac.airLoopHVACOutdoorAirSystem
  return true unless oa_sys.is_initialized

  oa_sys = oa_sys.get
  oa_control = oa_sys.getControllerOutdoorAir
  economizer_type = oa_control.getEconomizerControlType

  # Return true if no economizer is present
  if economizer_type == 'NoEconomizer'
    return true
  end

  # Determine the prohibited types
  prohibited_types = []
  case climate_zone
  when 'ASHRAE 169-2006-0B',
       'ASHRAE 169-2006-1B',
       'ASHRAE 169-2006-2B',
       'ASHRAE 169-2006-3B',
       'ASHRAE 169-2006-3C',
       'ASHRAE 169-2006-4B',
       'ASHRAE 169-2006-4C',
       'ASHRAE 169-2006-5B',
       'ASHRAE 169-2006-6B',
       'ASHRAE 169-2006-7A',
       'ASHRAE 169-2006-7B',
       'ASHRAE 169-2006-8A',
       'ASHRAE 169-2006-8B',
       'ASHRAE 169-2013-0B',
       'ASHRAE 169-2013-1B',
       'ASHRAE 169-2013-2B',
       'ASHRAE 169-2013-3B',
       'ASHRAE 169-2013-3C',
       'ASHRAE 169-2013-4B',
       'ASHRAE 169-2013-4C',
       'ASHRAE 169-2013-5B',
       'ASHRAE 169-2013-6B',
       'ASHRAE 169-2013-7A',
       'ASHRAE 169-2013-7B',
       'ASHRAE 169-2013-8A',
       'ASHRAE 169-2013-8B'
    prohibited_types = ['FixedEnthalpy']
  when 'ASHRAE 169-2006-0A',
       'ASHRAE 169-2006-1A',
       'ASHRAE 169-2006-2A',
       'ASHRAE 169-2006-3A',
       'ASHRAE 169-2006-4A',
       'ASHRAE 169-2013-0A',
       'ASHRAE 169-2013-1A',
       'ASHRAE 169-2013-2A',
       'ASHRAE 169-2013-3A',
       'ASHRAE 169-2013-4A'
    prohibited_types = ['FixedDryBulb', 'DifferentialDryBulb']
  when 'ASHRAE 169-2006-5A',
       'ASHRAE 169-2006-6A',
       'ASHRAE 169-2013-5A',
       'ASHRAE 169-2013-6A'
    prohibited_types = []
  end

  # Check if the specified type is allowed
  economizer_type_allowed = true
  if prohibited_types.include?(economizer_type)
    economizer_type_allowed = false
  end

  return economizer_type_allowed
end
air_loop_hvac_energy_recovery_ventilator_flow_limit(air_loop_hvac, climate_zone, pct_oa) click to toggle source

Determine the airflow limits that govern whether or not an ERV is required. Based on climate zone and % OA, plus the number of operating hours the system has.

@param air_loop_hvac [OpenStudio::Model::AirLoopHVAC] air loop @param climate_zone [String] ASHRAE climate zone, e.g. ‘ASHRAE 169-2013-4A’ @param pct_oa [Double] percentage of outdoor air @return [Double] the flow rate above which an ERV is required. if nil, ERV is never required.

# File lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.AirLoopHVAC.rb, line 442
def air_loop_hvac_energy_recovery_ventilator_flow_limit(air_loop_hvac, climate_zone, pct_oa)
  # Calculate the number of system operating hours
  # based on the availability schedule.
  ann_op_hrs = 0.0
  avail_sch = air_loop_hvac.availabilitySchedule
  if avail_sch == air_loop_hvac.model.alwaysOnDiscreteSchedule
    ann_op_hrs = 8760.0
  elsif avail_sch.to_ScheduleRuleset.is_initialized
    avail_sch = avail_sch.to_ScheduleRuleset.get
    ann_op_hrs = OpenstudioStandards::Schedules.schedule_ruleset_get_hours_above_value(avail_sch, 0.0)
  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

  if ann_op_hrs < 8000.0
    # Table 6.5.6.1-1, less than 8000 hrs
    search_criteria = {
      'template' => template,
      'climate_zone' => climate_zone,
      'under_8000_hours' => true,
      'nontransient_dwelling' => false,
      'enthalpy_recovery_ratio_design_conditions' => 'Cooling'
    }
    energy_recovery_limits = model_find_object(standards_data['energy_recovery'], search_criteria)
    if energy_recovery_limits.nil?
      # Repeat the search for heating
      search_criteria['enthalpy_recovery_ratio_design_conditions'] = 'Heating'
      energy_recovery_limits = model_find_object(standards_data['energy_recovery'], search_criteria)
      if energy_recovery_limits.nil?
        OpenStudio.logFree(OpenStudio::Warn, 'openstudio.ashrae_90_1_2019.AirLoopHVAC', "Cannot find energy recovery limits for template '#{template}', climate zone '#{climate_zone}', and under 8000 hours, assuming no energy recovery required.")
        return nil
      end
    end

    if pct_oa < 0.1
      erv_cfm = nil
    elsif pct_oa >= 0.1 && pct_oa < 0.2
      erv_cfm = energy_recovery_limits['10_to_20_percent_oa']
    elsif pct_oa >= 0.2 && pct_oa < 0.3
      erv_cfm = energy_recovery_limits['20_to_30_percent_oa']
    elsif pct_oa >= 0.3 && pct_oa < 0.4
      erv_cfm = energy_recovery_limits['30_to_40_percent_oa']
    elsif pct_oa >= 0.4 && pct_oa < 0.5
      erv_cfm = energy_recovery_limits['40_to_50_percent_oa']
    elsif pct_oa >= 0.5 && pct_oa < 0.6
      erv_cfm = energy_recovery_limits['50_to_60_percent_oa']
    elsif pct_oa >= 0.6 && pct_oa < 0.7
      erv_cfm = energy_recovery_limits['60_to_70_percent_oa']
    elsif pct_oa >= 0.7 && pct_oa < 0.8
      erv_cfm = energy_recovery_limits['70_to_80_percent_oa']
    elsif pct_oa >= 0.8
      erv_cfm = energy_recovery_limits['greater_than_80_percent_oa']
    end
  else
    # Check if air loop serves a non-transient dwelling unit,
    # currently non-transient dwelling units are residential
    # spaces in the apartment prototypes
    building_data = model_get_building_properties(air_loop_hvac.model)
    building_type = building_data['building_type']
    nontrans_dwel = false
    if building_type == 'MidriseApartment' || building_type == 'HighriseApartment'
      air_loop_hvac.thermalZones.each do |zone|
        next unless OpenstudioStandards::ThermalZone.thermal_zone_residential?(zone)

        nontrans_dwel = true
      end
    end

    # Table 6.5.6.1-2, above 8000 hrs
    search_criteria = {
      'template' => template,
      'climate_zone' => climate_zone,
      'under_8000_hours' => false,
      'nontransient_dwelling' => nontrans_dwel,
      'enthalpy_recovery_ratio_design_conditions' => 'Cooling'
    }
    energy_recovery_limits = model_find_object(standards_data['energy_recovery'], search_criteria)
    if energy_recovery_limits.nil?
      # Repeat the search for heating
      search_criteria['enthalpy_recovery_ratio_design_conditions'] = 'Heating'
      energy_recovery_limits = model_find_object(standards_data['energy_recovery'], search_criteria)
      if energy_recovery_limits.nil?
        OpenStudio.logFree(OpenStudio::Warn, 'openstudio.ashrae_90_1_2019.AirLoopHVAC', "Cannot find energy recovery limits for template '#{template}', climate zone '#{climate_zone}', and under 8000 hours, assuming no energy recovery required.")
        return nil
      end
    end
    if pct_oa < 0.1
      if nontrans_dwel
        erv_cfm = energy_recovery_limits['0_to_10_percent_oa']
      else
        erv_cfm = nil
      end
    elsif pct_oa >= 0.1 && pct_oa < 0.2
      erv_cfm = energy_recovery_limits['10_to_20_percent_oa']
    elsif pct_oa >= 0.2 && pct_oa < 0.3
      erv_cfm = energy_recovery_limits['20_to_30_percent_oa']
    elsif pct_oa >= 0.3 && pct_oa < 0.4
      erv_cfm = energy_recovery_limits['30_to_40_percent_oa']
    elsif pct_oa >= 0.4 && pct_oa < 0.5
      erv_cfm = energy_recovery_limits['40_to_50_percent_oa']
    elsif pct_oa >= 0.5 && pct_oa < 0.6
      erv_cfm = energy_recovery_limits['50_to_60_percent_oa']
    elsif pct_oa >= 0.6 && pct_oa < 0.7
      erv_cfm = energy_recovery_limits['60_to_70_percent_oa']
    elsif pct_oa >= 0.7 && pct_oa < 0.8
      erv_cfm = energy_recovery_limits['70_to_80_percent_oa']
    elsif pct_oa >= 0.8
      erv_cfm = energy_recovery_limits['greater_than_80_percent_oa']
    end
  end

  return erv_cfm
end
air_loop_hvac_integrated_economizer_required?(air_loop_hvac, climate_zone) click to toggle source

Determine if the system economizer must be integrated or not. All economizers must be integrated in 90.1-2019

@param air_loop_hvac [OpenStudio::Model::AirLoopHVAC] air loop @param climate_zone [String] ASHRAE climate zone, e.g. ‘ASHRAE 169-2013-4A’ @return [Boolean] returns true if required, false if not

# File lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.AirLoopHVAC.rb, line 86
def air_loop_hvac_integrated_economizer_required?(air_loop_hvac, climate_zone)
  return true
end
air_loop_hvac_motorized_oa_damper_limits(air_loop_hvac, climate_zone) click to toggle source

Determine the air flow and number of story limits for whether motorized OA damper is required.

@param air_loop_hvac [OpenStudio::Model::AirLoopHVAC] air loop @param climate_zone [String] ASHRAE climate zone, e.g. ‘ASHRAE 169-2013-4A’ @return [Array<Double>] [minimum_oa_flow_cfm, maximum_stories]. If both nil, never required

# File lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.AirLoopHVAC.rb, line 275
def air_loop_hvac_motorized_oa_damper_limits(air_loop_hvac, climate_zone)
  case climate_zone
  when 'ASHRAE 169-2006-0A',
       'ASHRAE 169-2006-1A',
       'ASHRAE 169-2006-0B',
       'ASHRAE 169-2006-1B',
       'ASHRAE 169-2006-2A',
       'ASHRAE 169-2006-2B',
       'ASHRAE 169-2006-3A',
       'ASHRAE 169-2006-3B',
       'ASHRAE 169-2006-3C',
       'ASHRAE 169-2013-0A',
       'ASHRAE 169-2013-1A',
       'ASHRAE 169-2013-0B',
       'ASHRAE 169-2013-1B',
       'ASHRAE 169-2013-2A',
       'ASHRAE 169-2013-2B',
       'ASHRAE 169-2013-3A',
       'ASHRAE 169-2013-3B',
       'ASHRAE 169-2013-3C'
    minimum_oa_flow_cfm = 0
    maximum_stories = 999 # Any number of stories
  else
    minimum_oa_flow_cfm = 0
    maximum_stories = 0
  end

  return [minimum_oa_flow_cfm, maximum_stories]
end
air_loop_hvac_multizone_vav_optimization_required?(air_loop_hvac, climate_zone) click to toggle source

Determine if multizone vav optimization is required. @note code_sections [90.1-2019_6.5.3.3]

@param air_loop_hvac [OpenStudio::Model::AirLoopHVAC] air loop @param climate_zone [String] ASHRAE climate zone, e.g. ‘ASHRAE 169-2013-4A’ @return [Boolean] returns true if required, false if not @todo Add exception logic for systems with AIA healthcare ventilation requirements dual duct systems

# File lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.AirLoopHVAC.rb, line 185
def air_loop_hvac_multizone_vav_optimization_required?(air_loop_hvac, climate_zone)
  multizone_opt_required = false

  # Not required for systems with fan-powered terminals
  num_fan_powered_terminals = 0
  air_loop_hvac.demandComponents.each do |comp|
    if comp.to_AirTerminalSingleDuctParallelPIUReheat.is_initialized || comp.to_AirTerminalSingleDuctSeriesPIUReheat.is_initialized
      num_fan_powered_terminals += 1
    end
  end
  if num_fan_powered_terminals > 0
    OpenStudio.logFree(OpenStudio::Info, 'openstudio.standards.AirLoopHVAC', "For #{air_loop_hvac.name}, multizone vav optimization is not required because the system has #{num_fan_powered_terminals} fan-powered terminals.")
    return multizone_opt_required
  end

  # Get the OA intake
  controller_oa = nil
  controller_mv = nil
  oa_system = nil
  if air_loop_hvac.airLoopHVACOutdoorAirSystem.is_initialized
    oa_system = air_loop_hvac.airLoopHVACOutdoorAirSystem.get
    controller_oa = oa_system.getControllerOutdoorAir
    controller_mv = controller_oa.controllerMechanicalVentilation
  else
    OpenStudio.logFree(OpenStudio::Info, 'openstudio.standards.AirLoopHVAC', "For #{air_loop_hvac.name}, multizone optimization is not applicable because system has no OA intake.")
    return multizone_opt_required
  end

  # Get the AHU design supply air flow rate
  dsn_flow_m3_per_s = nil
  if air_loop_hvac.designSupplyAirFlowRate.is_initialized
    dsn_flow_m3_per_s = air_loop_hvac.designSupplyAirFlowRate.get
  elsif air_loop_hvac.autosizedDesignSupplyAirFlowRate.is_initialized
    dsn_flow_m3_per_s = air_loop_hvac.autosizedDesignSupplyAirFlowRate.get
  else
    OpenStudio.logFree(OpenStudio::Warn, 'openstudio.standards.AirLoopHVAC', "For #{air_loop_hvac.name} design supply air flow rate is not available, cannot apply efficiency standard.")
    return multizone_opt_required
  end
  dsn_flow_cfm = OpenStudio.convert(dsn_flow_m3_per_s, 'm^3/s', 'cfm').get

  # Get the minimum OA flow rate
  min_oa_flow_m3_per_s = nil
  if controller_oa.minimumOutdoorAirFlowRate.is_initialized
    min_oa_flow_m3_per_s = controller_oa.minimumOutdoorAirFlowRate.get
  elsif controller_oa.autosizedMinimumOutdoorAirFlowRate.is_initialized
    min_oa_flow_m3_per_s = controller_oa.autosizedMinimumOutdoorAirFlowRate.get
  else
    OpenStudio.logFree(OpenStudio::Warn, 'openstudio.standards.AirLoopHVAC', "For #{controller_oa.name}: minimum OA flow rate is not available, cannot apply efficiency standard.")
    return multizone_opt_required
  end
  min_oa_flow_cfm = OpenStudio.convert(min_oa_flow_m3_per_s, 'm^3/s', 'cfm').get

  # Calculate the percent OA at design airflow
  pct_oa = min_oa_flow_m3_per_s / dsn_flow_m3_per_s

  # Not required for systems where
  # exhaust is more than 70% of the total OA intake.
  if pct_oa > 0.7
    OpenStudio.logFree(OpenStudio::Info, 'openstudio.standards.AirLoopHVAC', "For #{controller_oa.name}: multizone optimization is not applicable because system is more than 70% OA.")
    return multizone_opt_required
  end

  # @todo Not required for dual-duct systems
  # if self.isDualDuct
  # OpenStudio::logFree(OpenStudio::Info, "openstudio.standards.AirLoopHVAC", "For #{controller_oa.name}: multizone optimization is not applicable because it is a dual duct system")
  # return multizone_opt_required
  # end

  # If here, multizone vav optimization is required
  multizone_opt_required = true

  return multizone_opt_required
end
air_loop_hvac_single_zone_controls_num_stages(air_loop_hvac, climate_zone) click to toggle source

Determine the number of stages that should be used as controls for single zone DX systems. 90.1-2019 depends on the cooling capacity of the system.

@param air_loop_hvac [OpenStudio::Model::AirLoopHVAC] air loop @param climate_zone [String] ASHRAE climate zone, e.g. ‘ASHRAE 169-2013-4A’ @return [Integer] the number of stages: 0, 1, 2

# File lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.AirLoopHVAC.rb, line 311
def air_loop_hvac_single_zone_controls_num_stages(air_loop_hvac, climate_zone)
  min_clg_cap_btu_per_hr = 65_000
  clg_cap_btu_per_hr = OpenStudio.convert(air_loop_hvac_total_cooling_capacity(air_loop_hvac), 'W', 'Btu/hr').get
  if clg_cap_btu_per_hr >= min_clg_cap_btu_per_hr
    num_stages = 2
    OpenStudio.logFree(OpenStudio::Info, 'openstudio.standards.AirLoopHVAC', "For #{air_loop_hvac.name}: two-stage control is required since cooling capacity of #{clg_cap_btu_per_hr.round} Btu/hr exceeds the minimum of #{min_clg_cap_btu_per_hr.round} Btu/hr .")
  else
    num_stages = 1
    OpenStudio.logFree(OpenStudio::Info, 'openstudio.standards.AirLoopHVAC', "For #{air_loop_hvac.name}: two-stage control is not required since cooling capacity of #{clg_cap_btu_per_hr.round} Btu/hr is less than the minimum of #{min_clg_cap_btu_per_hr.round} Btu/hr .")
  end

  return num_stages
end
air_loop_hvac_standby_mode_occupancy_control(air_loop_hvac, standby_mode_spaces) click to toggle source

Add occupant standby controls to air loop When the thermostat schedule is setup or setback the ventilation is shutoff. Currently this is done by scheduling air terminal dampers (so load can still be met) and cycling unitary system fans

@param air_loop_hvac [OpenStudio::Model::AirLoopHVAC] OpenStudio AirLoopHVAC object @param standby_mode_spaces [Array<OpenStudio::Model::Space>] List of all spaces required to have standby mode controls @return [Boolean] true if sucessful, false otherwise

# File lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.AirLoopHVAC.rb, line 748
def air_loop_hvac_standby_mode_occupancy_control(air_loop_hvac, standby_mode_spaces)
  if air_loop_hvac_include_unitary_system?(air_loop_hvac)
    unitary_system = nil
    # Get unitary system
    air_loop_hvac.supplyComponents.each do |comp|
      if comp.to_AirLoopHVACUnitarySystem.is_initialized
        unitary_system = comp.to_AirLoopHVACUnitarySystem.get
      end
    end
    return false unless !unitary_system.nil?

    # Set fan operating schedule during assumed occupant standby mode time to 0 so the fan can cycle
    new_sch = model_set_schedule_value(unitary_system.supplyAirFanOperatingModeSchedule.get, '12' => 0)
    unitary_system.setSupplyAirFanOperatingModeSchedule(new_sch) unless new_sch.nil?
  else
    # Get thermal zones associated with spaces having standby mode occupancy requirements
    standby_mode_zones = []
    standby_mode_spaces.sort.each do |space|
      standby_mode_zones << space.thermalZone.get
    end
    # Schedule the MDP of terminals to a low value during occupant standby mode
    # The intent is to reduce ventilation while still allowing the terminal to
    # meet loads
    standby_mode_zones.each do |zone|
      air_terminal = zone.airLoopHVACTerminal
      if air_terminal.is_initialized
        air_terminal = air_terminal.get
        if air_terminal.to_AirTerminalSingleDuctVAVReheat.is_initialized
          air_terminal = air_terminal.to_AirTerminalSingleDuctVAVReheat.get
          if air_terminal.zoneMinimumAirFlowInputMethod == 'Constant' || air_terminal.zoneMinimumAirFlowInputMethod == 'FixedFlow'
            if air_terminal.zoneMinimumAirFlowInputMethod == 'FixedFlow'
              mdp_org = air_terminal.fixedMinimumAirFlowRate.get / air_terminal.autosizedMaximumAirFlowRate.get
              air_terminal.setFixedMinimumAirFlowRate(0)
            else
              mdp_org = air_terminal.constantMinimumAirFlowFraction.get
              air_terminal.setConstantMinimumAirFlowFraction(0)
            end
            air_terminal.setZoneMinimumAirFlowInputMethod('Scheduled')
            air_terminal.setMinimumAirFlowFractionSchedule(model_set_schedule_value(OpenstudioStandards::Schedules.create_constant_schedule_ruleset(air_loop_hvac.model, mdp_org, name: "#{air_terminal.name} - MDP", schedule_type_limit: 'Fraction'), '12' => 0.1))
          elsif air_terminal.zoneMinimumAirFlowInputMethod == 'Scheduled'
            air_terminal.setMinimumAirFlowFractionSchedule(model_set_schedule_value(air_terminal.minimumAirFlowFractionSchedule.get, '12' => 0.1))
          else
            OpenStudio.logFree(OpenStudio::Warn, 'openstudio.ashrae_90_1_2019.AirLoopHVAC', "The air terminal associated with #{zone.name} uses a zone minimum air flow input method that is currently not supported so occupant standby controls were not modeled.")
          end
        else
          OpenStudio.logFree(OpenStudio::Warn, 'openstudio.ashrae_90_1_2019.AirLoopHVAC', "The air terminal associated with #{zone.name} isn't of the SingleDuctVAVReheat type so occupant standby controls were not modeled.")
        end
      end
    end
  end

  return true
end
air_loop_hvac_supply_air_temperature_reset_required?(air_loop_hvac, climate_zone) click to toggle source

Determine if the system required supply air temperature (SAT) reset. For 90.1-2019, SAT reset requirements are based on climate zone. More exceptions are added for 90.1 2019 6.5.3.5

@param air_loop_hvac [OpenStudio::Model::AirLoopHVAC] air loop @param climate_zone [String] ASHRAE climate zone, e.g. ‘ASHRAE 169-2013-4A’ @return [Boolean] returns true if required, false if not

# File lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.AirLoopHVAC.rb, line 331
def air_loop_hvac_supply_air_temperature_reset_required?(air_loop_hvac, climate_zone)
  is_sat_reset_required = false

  # Only required for multizone VAV systems
  unless air_loop_hvac_multizone_vav_system?(air_loop_hvac)
    return is_sat_reset_required
  end

  # check if design outside air is less than 10,000cfm (5000L/s) 90.1 2019 6.5.3.5 Exception 1 and 2
  design_oa_m3s = nil
  if air_loop_hvac.sizingSystem.designOutdoorAirFlowRate.is_initialized
    design_oa_m3s = air_loop_hvac.sizingSystem.designOutdoorAirFlowRate.get
  elsif air_loop_hvac.sizingSystem.autosizedDesignOutdoorAirFlowRate.is_initialized
    design_oa_m3s = air_loop_hvac.sizingSystem.autosizedDesignOutdoorAirFlowRate.get
  else
    OpenStudio.logFree(OpenStudio::Warn, 'openstudio.standards.AirLoopHVAC', "For #{air_loop_hvac.name} design outdoor air flow rate is not available.")
  end
  design_oa_cfm = OpenStudio.convert(design_oa_m3s, 'm^3/s', 'cfm').get

  # check if there is erv 90.1 2019 Exceptions to 6.5.3.5 Exception 3
  has_erv = air_loop_hvac_energy_recovery?(air_loop_hvac)
  design_sa_m3s = air_loop_hvac_find_design_supply_air_flow_rate(air_loop_hvac)

  oa_ratio = 0
  if design_sa_m3s > 0
    oa_ratio = design_oa_m3s / design_sa_m3s
  end
  has_large_oa = (oa_ratio >= 0.8)

  case climate_zone
  when 'ASHRAE 169-2006-0A',
       'ASHRAE 169-2006-1A',
       'ASHRAE 169-2006-3A',
       'ASHRAE 169-2013-0A',
       'ASHRAE 169-2013-1A',
       'ASHRAE 169-2013-3A'
    if design_oa_cfm < 3000
      is_sat_reset_required = false
      OpenStudio.logFree(OpenStudio::Info, 'openstudio.standards.AirLoopHVAC', "For #{air_loop_hvac.name}: Supply air temperature reset is not required per 6.5.3.5 Exception 1, the system is located in climate zone #{climate_zone}.")
      return is_sat_reset_required
    end
    if has_erv && has_large_oa
      is_sat_reset_required = false
      OpenStudio.logFree(OpenStudio::Info, 'openstudio.standards.AirLoopHVAC', "For #{air_loop_hvac.name}: Supply air temperature reset is not required per 6.5.3.5 Exception 3, the system is located in climate zone #{climate_zone}.")
      return is_sat_reset_required
    end
    is_sat_reset_required = true
    OpenStudio.logFree(OpenStudio::Info, 'openstudio.standards.AirLoopHVAC', "For #{air_loop_hvac.name}: Supply air temperature reset is required.")
    return is_sat_reset_required
  when 'ASHRAE 169-2006-2A',
       'ASHRAE 169-2013-2A'
    if design_oa_cfm < 10000
      is_sat_reset_required = false
      OpenStudio.logFree(OpenStudio::Info, 'openstudio.standards.AirLoopHVAC', "For #{air_loop_hvac.name}: Supply air temperature reset is not required per 6.5.3.5 Exception 2, the system is located in climate zone #{climate_zone}.")
      return is_sat_reset_required
    end
    if has_erv && has_large_oa
      is_sat_reset_required = false
      OpenStudio.logFree(OpenStudio::Info, 'openstudio.standards.AirLoopHVAC', "For #{air_loop_hvac.name}: Supply air temperature reset is not required per 6.5.3.5 Exception 3, the system is located in climate zone #{climate_zone}.")
      return is_sat_reset_required
    end
    is_sat_reset_required = true
    OpenStudio.logFree(OpenStudio::Info, 'openstudio.standards.AirLoopHVAC', "For #{air_loop_hvac.name}: Supply air temperature reset is required.")
    return is_sat_reset_required
  when 'ASHRAE 169-2006-0B',
       'ASHRAE 169-2006-1B',
       'ASHRAE 169-2006-2B',
       'ASHRAE 169-2006-3B',
       'ASHRAE 169-2006-3C',
       'ASHRAE 169-2006-4A',
       'ASHRAE 169-2006-4B',
       'ASHRAE 169-2006-4C',
       'ASHRAE 169-2006-5A',
       'ASHRAE 169-2006-5B',
       'ASHRAE 169-2006-5C',
       'ASHRAE 169-2006-6A',
       'ASHRAE 169-2006-6B',
       'ASHRAE 169-2006-7A',
       'ASHRAE 169-2006-7B',
       'ASHRAE 169-2006-8A',
       'ASHRAE 169-2006-8B',
       'ASHRAE 169-2013-0B',
       'ASHRAE 169-2013-1B',
       'ASHRAE 169-2013-2B',
       'ASHRAE 169-2013-3B',
       'ASHRAE 169-2013-3C',
       'ASHRAE 169-2013-4A',
       'ASHRAE 169-2013-4B',
       'ASHRAE 169-2013-4C',
       'ASHRAE 169-2013-5A',
       'ASHRAE 169-2013-5B',
       'ASHRAE 169-2013-5C',
       'ASHRAE 169-2013-6A',
       'ASHRAE 169-2013-6B',
       'ASHRAE 169-2013-7A',
       'ASHRAE 169-2013-7B',
       'ASHRAE 169-2013-8A',
       'ASHRAE 169-2013-8B'
    is_sat_reset_required = true
    OpenStudio.logFree(OpenStudio::Info, 'openstudio.standards.AirLoopHVAC', "For #{air_loop_hvac.name}: Supply air temperature reset is required.")
    return is_sat_reset_required
  end
end
air_terminal_single_duct_vav_reheat_apply_initial_prototype_damper_position(air_terminal_single_duct_vav_reheat, zone_oa_per_area) click to toggle source

@!group AirTerminalSingleDuctVAVReheat Set the initial minimum damper position based on OA rate of the space and the template. Zones with low OA per area get lower initial guesses. Final position will be adjusted upward as necessary by Standards.AirLoopHVAC.apply_minimum_vav_damper_positions

@param air_terminal_single_duct_vav_reheat [OpenStudio::Model::AirTerminalSingleDuctVAVReheat] the air terminal object @param zone_oa_per_area [Double] the zone outdoor air per area in m^3/s*m^2 @return [Boolean] returns true if successful, false if not

# File lib/openstudio-standards/prototypes/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.AirTerminalSingleDuctVAVReheat.rb, line 10
def air_terminal_single_duct_vav_reheat_apply_initial_prototype_damper_position(air_terminal_single_duct_vav_reheat, zone_oa_per_area)
  min_damper_position = case air_terminal_single_duct_vav_reheat_reheat_type(air_terminal_single_duct_vav_reheat)
                        when 'HotWater'
                          0.2
                        when 'Electricity', 'NaturalGas'
                          0.3
                        else
                          0.2
                        end

  # Set the minimum flow fraction
  air_terminal_single_duct_vav_reheat.setConstantMinimumAirFlowFraction(min_damper_position)

  return true
end
air_terminal_single_duct_vav_reheat_minimum_damper_position(air_terminal_single_duct_vav_reheat, has_ddc = false) click to toggle source

Specifies the minimum damper position for VAV dampers. For terminals with hot water heat and DDC, the minimum is 20%, otherwise the minimum is 30%.

@param air_terminal_single_duct_vav_reheat [OpenStudio::Model::AirTerminalSingleDuctVAVReheat] the air terminal object @param has_ddc [Boolean] whether or not there is DDC control of the VAV terminal in question @return [Double] minimum damper position

# File lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.AirTerminalSingleDuctVAVReheat.rb, line 10
def air_terminal_single_duct_vav_reheat_minimum_damper_position(air_terminal_single_duct_vav_reheat, has_ddc = false)
  min_damper_position = nil
  case air_terminal_single_duct_vav_reheat_reheat_type(air_terminal_single_duct_vav_reheat)
  when 'HotWater'
    min_damper_position = if has_ddc
                            0.2
                          else
                            0.3
                          end
  when 'Electricity', 'NaturalGas'
    min_damper_position = 0.3
  end

  return min_damper_position
end
boiler_get_eff_fplr(boiler_hot_water) click to toggle source

Determine what part load efficiency degredation curve should be used for a boiler

@param boiler_hot_water [OpenStudio::Model::BoilerHotWater] hot water boiler object @return [String] returns name of the boiler curve to be used, or nil if not applicable

# File lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.BoilerHotWater.rb, line 6
def boiler_get_eff_fplr(boiler_hot_water)
  capacity_w = boiler_hot_water_find_capacity(boiler_hot_water)
  capacity_btu_per_hr = OpenStudio.convert(capacity_w, 'W', 'Btu/hr').get
  fplr = capacity_btu_per_hr >= 1_000_000 ? 'Boiler with Minimum Turndown' : 'Boiler with No Minimum Turndown'
  return fplr
end
chiller_electric_eir_get_cap_f_t_curve_name(chiller_electric_eir, compressor_type, cooling_type, chiller_tonnage, compliance_path) click to toggle source

Get applicable performance curve for capacity as a function of temperature

@param chiller_electric_eir [OpenStudio::Model::ChillerElectricEIR] chiller object @param compressor_type [String] compressor type @param cooling_type [String] cooling type (‘AirCooled’ or ‘WaterCooled’) @param chiller_tonnage [Double] chiller capacity in ton @return [String] name of applicable cuvre, nil if not found @todo the current assingment is meant to replicate what was in the data, it probably needs to be reviewed

# File lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.ChillerElectricEIR.rb, line 10
def chiller_electric_eir_get_cap_f_t_curve_name(chiller_electric_eir, compressor_type, cooling_type, chiller_tonnage, compliance_path)
  case cooling_type
  when 'AirCooled'
    return 'AirCooled_Chiller_2010_PathA_CAPFT'
  when 'WaterCooled'
    case compressor_type
    when 'Centrifugal'
      if compliance_path == 'Path A'
        return 'WaterCooled_Centrifugal_Chiller_2010_PathA_CAPFT'
      elsif compliance_path == 'Path B'
        return 'WaterCooled_Centrifugal_Chiller_2010_PathB_CAPFT'
      else
        return nil
      end
    when 'Reciprocating', 'Rotary Screw', 'Scroll'
      return 'ChlrWtrPosDispPathAAllQRatio_fTchwsTcwsSI'
    else
      return nil
    end
  else
    return nil
  end
end
chiller_electric_eir_get_eir_f_plr_curve_name(chiller_electric_eir, compressor_type, cooling_type, chiller_tonnage, compliance_path) click to toggle source

Get applicable performance curve for EIR as a function of part load ratio

@param chiller_electric_eir [OpenStudio::Model::ChillerElectricEIR] chiller object @param compressor_type [String] compressor type @param cooling_type [String] cooling type (‘AirCooled’ or ‘WaterCooled’) @param chiller_tonnage [Double] chiller capacity in ton @return [String] name of applicable cuvre, nil if not found @todo the current assingment is meant to replicate what was in the data, it probably needs to be reviewed

# File lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.ChillerElectricEIR.rb, line 74
def chiller_electric_eir_get_eir_f_plr_curve_name(chiller_electric_eir, compressor_type, cooling_type, chiller_tonnage, compliance_path)
  case cooling_type
  when 'AirCooled'
    return 'AirCooled_Chiller_AllCapacities_2004_2010_EIRFPLR'
  when 'WaterCooled'
    case compressor_type
    when 'Centrifugal'
      return 'ChlrWtrCentPathAAllEIRRatio_fQRatio'
    when 'Reciprocating', 'Rotary Screw', 'Scroll'
      return 'ChlrWtrPosDispPathAAllEIRRatio_fQRatio'
    else
      return nil
    end
  else
    return nil
  end
end
chiller_electric_eir_get_eir_f_t_curve_name(chiller_electric_eir, compressor_type, cooling_type, chiller_tonnage, compliance_path) click to toggle source

Get applicable performance curve for EIR as a function of temperature

@param chiller_electric_eir [OpenStudio::Model::ChillerElectricEIR] chiller object @param compressor_type [String] compressor type @param cooling_type [String] cooling type (‘AirCooled’ or ‘WaterCooled’) @param chiller_tonnage [Double] chiller capacity in ton @return [String] name of applicable cuvre, nil if not found @todo the current assingment is meant to replicate what was in the data, it probably needs to be reviewed

# File lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.ChillerElectricEIR.rb, line 42
def chiller_electric_eir_get_eir_f_t_curve_name(chiller_electric_eir, compressor_type, cooling_type, chiller_tonnage, compliance_path)
  case cooling_type
  when 'AirCooled'
    return 'AirCooled_Chiller_2010_PathA_EIRFT'
  when 'WaterCooled'
    case compressor_type
    when 'Centrifugal'
      if compliance_path == 'Path A'
        return 'WaterCooled_Centrifugal_Chiller_2010_PathA_EIRFT'
      elsif compliance_path == 'Path B'
        return 'WaterCooled_Centrifugal_Chiller_2010_PathB_EIRFT'
      else
        return nil
      end
    when 'Reciprocating', 'Rotary Screw', 'Scroll'
      return 'ChlrWtrPosDispPathAAllEIRRatio_fTchwsTcwsSI'
    else
      return nil
    end
  else
    return nil
  end
end
coil_heating_gas_additional_search_criteria(coil_heating_gas, search_criteria) click to toggle source

Applies the standard efficiency ratings to CoilHeatingGas.

@param coil_heating_gas [OpenStudio::Model::CoilHeatingGas] coil heating gas object @param search_criteria [Hash] search criteria for looking up furnace data @return [Hash] updated search criteria

# File lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.CoilHeatingGas.rb, line 7
def coil_heating_gas_additional_search_criteria(coil_heating_gas, search_criteria)
  capacity_w = coil_heating_gas_find_capacity(coil_heating_gas)
  capacity_btu_per_hr = OpenStudio.convert(capacity_w, 'W', 'Btu/hr').get
  if capacity_btu_per_hr < 225_000
    search_criteria['subtype'] = 'Weatherized' # assumption; could be based on input
  end
  return search_criteria
end
cooling_tower_variable_speed_apply_efficiency_and_curves(cooling_tower_variable_speed) click to toggle source

Apply the efficiency, plus Multicell heat rejection with VSD

@param cooling_tower_variable_speed [OpenStudio::Model::CoolingTowerVariableSpeed] variable speed cooling tower @return [Boolean] returns true if successful, false if not

# File lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.CoolingTowerVariableSpeed.rb, line 10
def cooling_tower_variable_speed_apply_efficiency_and_curves(cooling_tower_variable_speed)
  cooling_tower_apply_minimum_power_per_flow(cooling_tower_variable_speed)
  cooling_tower_variable_speed.setCellControl('MaximalCell')
  return true
end
fan_constant_volume_airloop_fan_pressure_rise(fan_constant_volume) click to toggle source

Determine the prototype fan pressure rise for a constant volume fan on an AirLoopHVAC based on system airflow. Defaults to the logic from ASHRAE 90.1-2004 prototypes.

@param fan_constant_volume [OpenStudio::Model::FanConstantVolume] constant volume fan object @return [Double] pressure rise in inches H20

# File lib/openstudio-standards/prototypes/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.FanConstantVolume.rb, line 9
def fan_constant_volume_airloop_fan_pressure_rise(fan_constant_volume)
  # Get the max flow rate from the fan.
  maximum_flow_rate_m3_per_s = nil
  if fan_constant_volume.maximumFlowRate.is_initialized
    maximum_flow_rate_m3_per_s = fan_constant_volume.maximumFlowRate.get
  elsif fan_constant_volume.autosizedMaximumFlowRate.is_initialized
    maximum_flow_rate_m3_per_s = fan_constant_volume.autosizedMaximumFlowRate.get
  else
    OpenStudio.logFree(OpenStudio::Warn, 'openstudio.prototype.FanConstantVolume', "For #{fan_constant_volume.name} max flow rate is not available, cannot apply prototype assumptions.")
    return false
  end

  # Convert max flow rate to cfm
  maximum_flow_rate_cfm = OpenStudio.convert(maximum_flow_rate_m3_per_s, 'm^3/s', 'cfm').get

  # Determine the pressure rise
  pressure_rise_in_h2o = if maximum_flow_rate_cfm < 7437
                           2.5
                         else # Over 7,437 cfm
                           4.09
                         end

  return pressure_rise_in_h2o
end
fan_on_off_airloop_or_unitary_fan_pressure_rise(fan_on_off) click to toggle source

Determine the prototype fan pressure rise for an on off fan on an AirLoopHVAC or inside a unitary system based on system airflow. Defaults to the logic from ASHRAE 90.1-2004 prototypes.

@param fan_on_off [OpenStudio::Model::FanOnOff] on off fan object @return [Double] pressure rise in inches H20

# File lib/openstudio-standards/prototypes/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.FanOnOff.rb, line 9
def fan_on_off_airloop_or_unitary_fan_pressure_rise(fan_on_off)
  # Get the max flow rate from the fan.
  maximum_flow_rate_m3_per_s = nil
  if fan_on_off.maximumFlowRate.is_initialized
    maximum_flow_rate_m3_per_s = fan_on_off.maximumFlowRate.get
  elsif fan_on_off.autosizedMaximumFlowRate.is_initialized
    maximum_flow_rate_m3_per_s = fan_on_off.autosizedMaximumFlowRate.get
  else
    OpenStudio.logFree(OpenStudio::Warn, 'openstudio.prototype.FanOnOff', "For #{fan_on_off.name} max flow rate is not available, cannot apply prototype assumptions.")
    return false
  end

  # Convert max flow rate to cfm
  maximum_flow_rate_cfm = OpenStudio.convert(maximum_flow_rate_m3_per_s, 'm^3/s', 'cfm').get

  # Determine the pressure rise
  pressure_rise_in_h2o = if maximum_flow_rate_cfm < 7437
                           2.5
                         else # Over 7,437 cfm
                           4.09
                         end

  return pressure_rise_in_h2o
end
fan_variable_volume_airloop_fan_pressure_rise(fan_variable_volume) click to toggle source

Determine the prototype fan pressure rise for a variable volume fan on an AirLoopHVAC based on system airflow. Defaults to the logic from ASHRAE 90.1-2004 prototypes.

@param fan_variable_volume [OpenStudio::Model::FanVariableVolume] variable volume fan object @return [Double] pressure rise in inches H20

# File lib/openstudio-standards/prototypes/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.FanVariableVolume.rb, line 9
def fan_variable_volume_airloop_fan_pressure_rise(fan_variable_volume)
  # Get the max flow rate from the fan.
  maximum_flow_rate_m3_per_s = nil
  if fan_variable_volume.maximumFlowRate.is_initialized
    maximum_flow_rate_m3_per_s = fan_variable_volume.maximumFlowRate.get
  elsif fan_variable_volume.autosizedMaximumFlowRate.is_initialized
    maximum_flow_rate_m3_per_s = fan_variable_volume.autosizedMaximumFlowRate.get
  else
    OpenStudio.logFree(OpenStudio::Warn, 'openstudio.prototype.FanVariableVolume', "For #{fan_variable_volume.name} max flow rate is not available, cannot apply prototype assumptions.")
    return false
  end

  # Convert max flow rate to cfm
  maximum_flow_rate_cfm = OpenStudio.convert(maximum_flow_rate_m3_per_s, 'm^3/s', 'cfm').get

  # Determine the pressure rise
  pressure_rise_in_h2o = if maximum_flow_rate_cfm < 4648
                           4.0
                         else # Over 7,437 cfm
                           5.58
                         end

  return pressure_rise_in_h2o
end
fan_variable_volume_part_load_fan_power_limitation_capacity_limit(fan_variable_volume) click to toggle source

The threhold capacity below which part load control is not required. Per 90.1-2019, table 6.5.3.2.1: the cooling capacity threshold is 75000 instead of 110000 as of 1/1/2014

@param fan_variable_volume [OpenStudio::Model::FanVariableVolume] variable volume fan object @return [Double] the limit, in Btu/hr. Return nil for no limit by default.

# File lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.FanVariableVolume.rb, line 29
def fan_variable_volume_part_load_fan_power_limitation_capacity_limit(fan_variable_volume)
  cap_limit_btu_per_hr = case fan_variable_volume_cooling_system_type(fan_variable_volume)
                         when 'dx'
                           65_000
                         end

  return cap_limit_btu_per_hr
end
fan_variable_volume_part_load_fan_power_limitation_hp_limit(fan_variable_volume) click to toggle source

The threhold horsepower below which part load control is not required. Per 90.1-2019, table 6.5.3.2.1: the fan motor size for chiller-water and evaporative cooling is 0.25 hp as of 1/1/2014 instead of 5 hp

@param fan_variable_volume [OpenStudio::Model::FanVariableVolume] variable volume fan object @return [Double] the limit, in horsepower. Return nil for no limit by default.

# File lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.FanVariableVolume.rb, line 10
def fan_variable_volume_part_load_fan_power_limitation_hp_limit(fan_variable_volume)
  hp_limit = case fan_variable_volume_cooling_system_type(fan_variable_volume)
             when 'dx'
               0.0
             when 'chw'
               0.25
             when 'evap'
               0.25
             end

  return hp_limit
end
load_standards_database(data_directories = []) click to toggle source

Loads the openstudio standards dataset for this standard.

@param data_directories [Array<String>] array of file paths that contain standards data @return [Hash] a hash of standards data

Calls superclass method ASHRAE901#load_standards_database
# File lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.rb, line 17
def load_standards_database(data_directories = [])
  super([__dir__] + data_directories)
end
model_add_lights_shutoff(model) click to toggle source

Implement occupancy based lighting level threshold (0.02 W/sqft). This is only for ASHRAE 90.1 2016 onwards. @note code_sections [90.1-2016_9.4.1.1.h/i] @author Xuechen (Jerry) Lei, PNNL

@param model [OpenStudio::Model::Model] OpenStudio Model @return [Boolean] returns true if successful, false if not

# File lib/openstudio-standards/prototypes/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.Model.rb, line 237
  def model_add_lights_shutoff(model)
    zones = model.getThermalZones
    num_zones = 0
    business_sch_name = prototype_input['business_schedule']
    return if business_sch_name.nil? # This is only for 10 prototypes that do not have continuous operation.

    # Add business schedule
    model_add_schedule(model, business_sch_name)

    # Add EMS object for business schedule variable
    business_sensor = OpenStudio::Model::EnergyManagementSystemSensor.new(model, 'Schedule Value')
    business_sensor.setKeyName(business_sch_name)
    business_sensor.setName('Business_Sensor')
    business_sensor_name = business_sensor.name.to_s

    space_types_affected = []
    zones.sort.each do |zone|
      spaces = zone.spaces
      if spaces.length != 1
        puts 'warning, there are more than one spaces in the zone, need to confirm the implementation'
      end
      space = spaces[0]
      space_lights = space.lights
      lights_defined_by_spacetype = false
      if space_lights.empty?
        space_lights = space.spaceType.get.lights
        lights_defined_by_spacetype = true
        space_types_affected << space.spaceType
      end
      space_people = space.people
      if space_people.empty?
        space_people = space.spaceType.get.people
      end

      # guard clause to skip space with no lights
      next if space_lights.empty?

      # if lights are defined at the space type level, clone each lights object and make it individual to the space
      new_space_lights = []
      if lights_defined_by_spacetype
        space_lights.each do |lights|
          new_lights = lights.clone.to_Lights.get
          new_lights.setName("#{space.name}-#{lights.name}")
          new_lights.setSpace(space)
          new_space_lights << new_lights
        end
        space_lights = new_space_lights
      end

      zone_name = zone.name.to_s
      next if zone_name =~ /data\s*center/i # skip data centers

      # EnergyPlus v9.4.0 / OpenStudio v3.1.0 variable name change from 'Zone Lights Electric Power' to 'Zone Lights Electricity Rate'
      # EnergyPlus v9.6.0 / OpenStudio v3.3.0 added Space objects, variable name change from 'Zone Lights Electricity Rate' to 'Space Lights Electricity Rate'
      # https://github.com/NREL/OpenStudio/pull/4104
      if model.version < OpenStudio::VersionString.new('3.1.0')
        light_sensor = OpenStudio::Model::EnergyManagementSystemSensor.new(model, 'Zone Lights Electric Power')
        key_name = zone_name
      elsif model.version < OpenStudio::VersionString.new('3.3.0')
        light_sensor = OpenStudio::Model::EnergyManagementSystemSensor.new(model, 'Zone Lights Electricity Rate')
        key_name = zone_name
      else
        light_sensor = OpenStudio::Model::EnergyManagementSystemSensor.new(model, 'Space Lights Electricity Rate')
        key_name = space.name.to_s
      end
      light_sensor.setKeyName(key_name)
      light_sensor.setName("#{key_name}_LSr".gsub(/[\s-]/, ''))
      light_sensor_name = light_sensor.name.to_s

      # get the space floor area for calculations
      space_floor_area = space.floorArea

      # account for multiple lights (also work for single light)
      big_light = space_lights[0] # find the light with highest power (assuming specified by watts/area)
      space_lights.each do |light_x|
        big_light_power = big_light.definition.to_LightsDefinition.get.wattsperSpaceFloorArea.to_f
        light_x_power = light_x.definition.to_LightsDefinition.get.wattsperSpaceFloorArea.to_f
        if light_x_power > big_light_power
          big_light = light_x
        end
      end

      add_lights_prog_0 = ''
      add_lights_prog_null = ''
      light_id = 0
      space_lights.each do |light_x|
        light_id += 1
        # EnergyPlus v9.4 name change for EMS actuators
        # https://github.com/NREL/OpenStudio/pull/4104
        if model.version < OpenStudio::VersionString.new('3.1.0')
          light_x_actuator = OpenStudio::Model::EnergyManagementSystemActuator.new(light_x, 'Lights', 'Electric Power Level')
        else
          light_x_actuator = OpenStudio::Model::EnergyManagementSystemActuator.new(light_x, 'Lights', 'Electricity Rate')
        end
        light_x_actuator.setName("#{key_name}_Light#{light_id}_Actuator".gsub(/[\s-]/, ''))
        light_x_actuator_name = light_x_actuator.name.to_s
        add_lights_prog_null += "\n      SET #{light_x_actuator_name} = NULL,"
        if light_x == big_light
          add_lights_prog_0 += "\n      SET #{light_x_actuator_name} = 0.02*#{space_floor_area}/0.09290304,"
          next
        end
        add_lights_prog_0 += "\n      SET #{light_x_actuator_name} = 0,"
      end

      light_ems_prog = OpenStudio::Model::EnergyManagementSystemProgram.new(model)
      light_ems_prog.setName("SET_#{key_name}_Light_EMS_Program".gsub(/[\s-]/, ''))
      light_ems_prog_body = <<-EMS
      SET #{light_sensor_name}_IP=0.093*#{light_sensor_name}/#{space_floor_area},
      IF (#{business_sensor_name} <= 0) && (#{light_sensor_name}_IP >= 0.02),#{add_lights_prog_0}
      ELSE,#{add_lights_prog_null}
      ENDIF
      EMS
      light_ems_prog.setBody(light_ems_prog_body)

      light_ems_prog_manager = OpenStudio::Model::EnergyManagementSystemProgramCallingManager.new(model)
      light_ems_prog_manager.setName("SET_#{key_name}_Light_EMS_Program_Manager")
      light_ems_prog_manager.setCallingPoint('AfterPredictorAfterHVACManagers')
      light_ems_prog_manager.addProgram(light_ems_prog)
    end

    # remove lights at the space type level
    space_types_affected.each do |space_type|
      space_type.get.lights.each(&:remove)
    end

    return true
  end
model_cw_loop_cooling_tower_fan_type(model) click to toggle source

Determine which type of fan the cooling tower will have. Variable Speed Fan for ASHRAE 90.1-2019.

@param model [OpenStudio::Model::Model] OpenStudio model object @return [String] the fan type: TwoSpeed Fan, Variable Speed Fan

# File lib/openstudio-standards/prototypes/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.hvac_systems.rb, line 9
def model_cw_loop_cooling_tower_fan_type(model)
  fan_type = 'Variable Speed Fan'
  return fan_type
end
model_door_infil_flow_rate_metal_coiling_cfm_ft2(climate_zone) click to toggle source

Metal coiling door code minimum infiltration rate at 75 Pa @note code_sections [90.1-2019_5.4.3.2]

@param climate_zone [String] ASHRAE climate zone, e.g. ‘ASHRAE 169-2013-4A’ @return [Double] Minimum infiltration rate for metal coiling doors

# File lib/openstudio-standards/prototypes/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.Model.rb, line 215
def model_door_infil_flow_rate_metal_coiling_cfm_ft2(climate_zone)
  case climate_zone
    when 'ASHRAE 169-2006-7A',
         'ASHRAE 169-2006-7B',
         'ASHRAE 169-2006-8A',
         'ASHRAE 169-2006-8B',
         'ASHRAE 169-2013-7A',
         'ASHRAE 169-2013-7B',
         'ASHRAE 169-2013-8A',
         'ASHRAE 169-2013-8B'
      return 0.4
    else
      return 1.0
  end
end
model_economizer_type(model, climate_zone) click to toggle source

Determine the prototypical economizer type for the model.

@param model [OpenStudio::Model::Model] OpenStudio model object @param climate_zone [String] ASHRAE climate zone, e.g. ‘ASHRAE 169-2013-4A’ @return [String] the economizer type. Possible values are:

'NoEconomizer'
'FixedDryBulb'
'FixedEnthalpy'
'DifferentialDryBulb'
'DifferentialEnthalpy'
'FixedDewPointAndDryBulb'
'ElectronicEnthalpy'
'DifferentialDryBulbAndEnthalpy'
# File lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.AirLoopHVAC.rb, line 17
def model_economizer_type(model, climate_zone)
  economizer_type = case climate_zone
                    when 'ASHRAE 169-2006-0A',
                        'ASHRAE 169-2006-1A',
                        'ASHRAE 169-2006-2A',
                        'ASHRAE 169-2006-3A',
                        'ASHRAE 169-2006-4A',
                        'ASHRAE 169-2013-0A',
                        'ASHRAE 169-2013-1A',
                        'ASHRAE 169-2013-2A',
                        'ASHRAE 169-2013-3A',
                        'ASHRAE 169-2013-4A'
                      'DifferentialEnthalpy'
                    else
                      'DifferentialDryBulb'
                    end
  return economizer_type
end
model_elevator_fan_pwr(model, vent_rate_cfm) click to toggle source

Determines the power of the elevator ventilation fan. 90.1-2019 has a requirement for ventilation fan efficiency.

@param model [OpenStudio::Model::Model] OpenStudio model object @param vent_rate_cfm [Double] the ventilation rate in ft^3/min @return [Double] the ventilation fan power in watts

# File lib/openstudio-standards/prototypes/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.Model.elevators.rb, line 21
def model_elevator_fan_pwr(model, vent_rate_cfm)
  vent_pwr_per_flow_w_per_cfm = 0.33
  vent_pwr_w = vent_pwr_per_flow_w_per_cfm * vent_rate_cfm
  # addendum 90.1-2007 aj has requirement on efficiency
  vent_pwr_w = vent_pwr_w * 0.29 / 0.70

  return vent_pwr_w
end
model_elevator_lighting_pct_incandescent(model) click to toggle source

Determines the percentage of the elevator cab lighting that is incandescent. The remainder is assumed to be LED. Defaults to 0% incandescent (100% LED), representing newer elevators.

@param model [OpenStudio::Model::Model] OpenStudio model object @return [Double] incandescent lighting percentage

# File lib/openstudio-standards/prototypes/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.Model.elevators.rb, line 10
def model_elevator_lighting_pct_incandescent(model)
  pct_incandescent = 0.0 # 100% LED
  return pct_incandescent
end
model_fenestration_orientation(model, climate_zone) click to toggle source

Adjust model to comply with fenestration orientation requirements @note code_sections [90.1-2013_5.5.4.5]

@param model [OpenStudio::Model::Model] OpenStudio model object @param climate_zone [String] ASHRAE climate zone, e.g. ‘ASHRAE 169-2013-4A’ @return [Boolean] Returns true if successful, false otherwise

# File lib/openstudio-standards/prototypes/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.Model.rb, line 10
def model_fenestration_orientation(model, climate_zone)
  # Building rotation to meet the same code requirement for
  # 90.1-2010 are kept
  if model.getBuilding.standardsBuildingType.is_initialized
    building_type = model.getBuilding.standardsBuildingType.get

    case building_type
      when 'Hospital'
        # Rotate the building counter-clockwise
        OpenstudioStandards::Geometry.model_set_building_north_axis(model, 270.0)
      when 'SmallHotel'
        # Rotate the building clockwise
        OpenstudioStandards::Geometry.model_set_building_north_axis(model, 180)
    end
  end

  wwr = false
  # Section 6.2.1.2 in the ANSI/ASHRAE/IES Standard 90.1-2013 Determination
  # of Energy Savings: Quantitative Analysis mentions that the SHGC trade-off
  # path is most likely to be used by designers for compliance.
  #
  # The following adjustment are only made for models with simple glazing objects
  non_simple_glazing = false
  shgc_a = 0
  model.getSpaces.each do |space|
    # Get thermal zone multiplier
    multiplier = space.thermalZone.get.multiplier

    space.surfaces.each do |surface|
      surface.subSurfaces.each do |subsurface|
        # Get window subsurface type
        subsurface_type = subsurface.subSurfaceType.to_s.downcase

        # Window, glass doors
        next unless (subsurface_type.include? 'window') || (subsurface_type.include? 'glass')

        # Check if non simple glazing fenestration objects are used
        subsurface_cons = subsurface.construction.get.to_Construction.get
        non_simple_glazing = true unless subsurface_cons.layers[0].to_SimpleGlazing.is_initialized

        if non_simple_glazing
          OpenStudio.logFree(OpenStudio::Warn, 'openstudio.ashrae_90_1_2013.model', 'Fenestration objects in the model use non-simple glazing models, fenestration requirements are not applied')
          return false
        end

        # Get subsurface's simple glazing object
        subsurface_shgc = subsurface_cons.layers[0].to_SimpleGlazing.get.solarHeatGainCoefficient

        # Get subsurface area
        subsurface_area = subsurface.grossArea * subsurface.multiplier * multiplier

        # SHGC * Area
        shgc_a += subsurface_shgc * subsurface_area
      end
    end
  end

  # Calculate West, East and total fenestration area
  a_n = OpenstudioStandards::Geometry.model_get_exterior_window_and_wall_area_by_orientation(model)['north_window']
  a_s = OpenstudioStandards::Geometry.model_get_exterior_window_and_wall_area_by_orientation(model)['south_window']
  a_e = OpenstudioStandards::Geometry.model_get_exterior_window_and_wall_area_by_orientation(model)['east_window']
  a_w = OpenstudioStandards::Geometry.model_get_exterior_window_and_wall_area_by_orientation(model)['west_window']
  a_t = a_n + a_s + a_e + a_w

  return true if a_t == 0.0

  # For prototypes SHGC_c assumed to be the building's weighted average SHGC
  shgc_c = shgc_a / a_t
  shgc_c = shgc_c.round(2)

  # West and East facing WWR
  wwr_w = OpenstudioStandards::Geometry.model_get_exterior_window_to_wall_ratio(model, cardinal_direction: 'W')
  wwr_e = OpenstudioStandards::Geometry.model_get_exterior_window_to_wall_ratio(model, cardinal_direction: 'E')

  # Calculate new SHGC for west and east facing fenestration;
  # Create new simple glazing object and assign it to all
  # West and East fenestration
  #
  # Exception 5 is applied when applicable
  shgc_w = 0
  shgc_e = 0

  # Determine requirement criteria
  case climate_zone
    when 'ASHRAE 169-2006-0A',
         'ASHRAE 169-2006-0B',
         'ASHRAE 169-2006-1A',
         'ASHRAE 169-2006-1B',
         'ASHRAE 169-2006-2A',
         'ASHRAE 169-2006-2B',
         'ASHRAE 169-2006-3A',
         'ASHRAE 169-2006-3B',
         'ASHRAE 169-2006-3C',
         'ASHRAE 169-2013-0A',
         'ASHRAE 169-2013-0B',
         'ASHRAE 169-2013-1A',
         'ASHRAE 169-2013-1B',
         'ASHRAE 169-2013-2A',
         'ASHRAE 169-2013-2B',
         'ASHRAE 169-2013-3A',
         'ASHRAE 169-2013-3B',
         'ASHRAE 169-2013-3C'
      criteria = 4
    when 'ASHRAE 169-2006-4A',
         'ASHRAE 169-2006-4B',
         'ASHRAE 169-2006-4C',
         'ASHRAE 169-2006-5A',
         'ASHRAE 169-2006-5B',
         'ASHRAE 169-2006-5C',
         'ASHRAE 169-2006-6A',
         'ASHRAE 169-2006-6B',
         'ASHRAE 169-2006-7A',
         'ASHRAE 169-2006-7B',
         'ASHRAE 169-2006-8A',
         'ASHRAE 169-2006-8B',
         'ASHRAE 169-2013-4A',
         'ASHRAE 169-2013-4B',
         'ASHRAE 169-2013-4C',
         'ASHRAE 169-2013-5A',
         'ASHRAE 169-2013-5B',
         'ASHRAE 169-2013-5C',
         'ASHRAE 169-2013-6A',
         'ASHRAE 169-2013-6B',
         'ASHRAE 169-2013-7A',
         'ASHRAE 169-2013-7B',
         'ASHRAE 169-2013-8A',
         'ASHRAE 169-2013-8B'
      criteria = 5
    else
      return false
  end

  if !((a_w <= a_t / criteria) && (a_e <= a_t / criteria))
    # Calculate new SHGC
    if wwr_w > 0.2
      shgc_w = a_t * shgc_c / (criteria * a_w)
    end
    if wwr_e > 0.2
      shgc_e = a_t * shgc_c / (criteria * a_w)
    end

    # No SHGC adjustment needed
    return true if shgc_w == 0 && shgc_e == 0

    model.getSpaces.each do |space|
      # Get thermal zone multiplier
      multiplier = space.thermalZone.get.multiplier

      space.surfaces.each do |surface|
        # Proceed only for East and West facing surfaces that are required
        # to have their SHGC adjusted
        next unless (OpenstudioStandards::Geometry.surface_get_cardinal_direction(surface) == 'W' && shgc_w > 0) ||
                    (OpenstudioStandards::Geometry.surface_get_cardinal_direction(surface) == 'E' && shgc_e > 0)

        surface.subSurfaces.each do |subsurface|
          # Get window subsurface type
          subsurface_type = subsurface.subSurfaceType.to_s.downcase

          # Window, glass doors
          next unless (subsurface_type.include? 'window') || (subsurface_type.include? 'glass')

          new_shgc = OpenstudioStandards::Geometry.surface_get_cardinal_direction(surface) == 'W' ? shgc_w : shgc_e
          new_shgc = new_shgc.round(2)

          # Get construction/simple glazing associated with the subsurface
          subsurface_org_cons = subsurface.construction.get.to_Construction.get
          subsurface_org_cons_mat = subsurface_org_cons.layers[0].to_SimpleGlazing.get

          # Only proceed if new SHGC is different than orignal one
          next unless (new_shgc - subsurface_org_cons_mat.solarHeatGainCoefficient).abs > 0

          # Clone construction/simple glazing associated with the subsurface
          subsurface_new_cons = subsurface_org_cons.clone(model).to_Construction.get
          subsurface_new_cons.setName("#{subsurface.name} Wind Cons U-#{OpenStudio.convert(subsurface_org_cons_mat.uFactor, 'W/m^2*K', 'Btu/ft^2*h*R').get.round(2)} SHGC #{new_shgc}")
          subsurface_new_cons_mat = subsurface_org_cons_mat.clone(model).to_SimpleGlazing.get
          subsurface_new_cons_mat.setName("#{subsurface.name} Wind SG Mat U-#{OpenStudio.convert(subsurface_org_cons_mat.uFactor, 'W/m^2*K', 'Btu/ft^2*h*R').get.round(2)} SHGC #{new_shgc}")
          subsurface_new_cons_mat.setSolarHeatGainCoefficient(new_shgc)
          new_layers = OpenStudio::Model::MaterialVector.new
          new_layers << subsurface_new_cons_mat
          subsurface_new_cons.setLayers(new_layers)

          # Assign new construction to sub surface
          subsurface.setConstruction(subsurface_new_cons)
        end
      end
    end
  end

  return true
end
model_transfer_air_required?(model) click to toggle source

Is transfer air required? @note code_sections [90.1-2019_6.5.7.1]

@param model [OpenStudio::Model::Model] OpenStudio model object @return [Boolean] returns true if transfer air is required, false if not

# File lib/openstudio-standards/prototypes/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.Model.rb, line 206
def model_transfer_air_required?(model)
  return true
end
pump_standard_minimum_motor_efficiency_and_size(pump, motor_bhp) click to toggle source

Determines the minimum pump motor efficiency and nominal size for a given motor bhp. This should be the total brake horsepower with any desired safety factor already included. This method picks the next nominal motor catgory larger than the required brake horsepower, and the efficiency is based on that size. For example, if the bhp = 6.3, the nominal size will be 7.5HP and the efficiency for 90.1-2010 will be 91.7% from Table 10.8B. This method assumes 4-pole, 1800rpm totally-enclosed fan-cooled motors.

@param motor_bhp [Double] motor brake horsepower (hp) @return [Array<Double>] minimum motor efficiency (0.0 to 1.0), nominal horsepower

# File lib/openstudio-standards/prototypes/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.Pump.rb, line 15
def pump_standard_minimum_motor_efficiency_and_size(pump, motor_bhp)
  motor_eff = 0.85
  nominal_hp = motor_bhp

  # Don't attempt to look up motor efficiency
  # for zero-hp pumps (required for circulation-pump-free
  # service water heating systems).
  return [1.0, 0] if motor_bhp == 0.0

  # Lookup the minimum motor efficiency
  motors = standards_data['motors']

  # Assuming all pump motors are 4-pole ODP
  search_criteria = {
    'template' => template,
    'number_of_poles' => 4.0,
    'type' => 'Enclosed'
  }

  motor_properties = model_find_object(motors, search_criteria, motor_bhp)
  if motor_properties.nil?
    OpenStudio.logFree(OpenStudio::Error, 'openstudio.standards.Pump', "For #{pump.name}, could not find motor properties using search criteria: #{search_criteria}, motor_bhp = #{motor_bhp} hp.")
    return [motor_eff, nominal_hp]
  end

  motor_eff = motor_properties['nominal_full_load_efficiency']
  nominal_hp = motor_properties['maximum_capacity'].to_f.round(1)
  # Round to nearest whole HP for niceness
  if nominal_hp >= 2
    nominal_hp = nominal_hp.round
  end

  # Get the efficiency based on the nominal horsepower
  # Add 0.01 hp to avoid search errors.
  motor_properties = model_find_object(motors, search_criteria, nominal_hp + 0.01)
  if motor_properties.nil?
    OpenStudio.logFree(OpenStudio::Error, 'openstudio.standards.Fan', "For #{pump.name}, could not find nominal motor properties using search criteria: #{search_criteria}, motor_hp = #{nominal_hp} hp.")
    return [motor_eff, nominal_hp]
  end
  motor_eff = motor_properties['nominal_full_load_efficiency']

  # Get flow rate (whether autosized or hard-sized)
  flow_m3_per_s = 0
  flow_m3_per_s = if pump.to_PumpVariableSpeed.is_initialized || pump.to_PumpConstantSpeed.is_initialized
                    if pump.ratedFlowRate.is_initialized
                      pump.ratedFlowRate.get
                    elsif pump.autosizedRatedFlowRate.is_initialized
                      pump.autosizedRatedFlowRate.get
                    end
                  elsif pump.to_HeaderedPumpsVariableSpeed.is_initialized || pump.to_HeaderedPumpsConstantSpeed.is_initialized
                    if pump.totalRatedFlowRate.is_initialized
                      pump.totalRatedFlowRate.get / pump.numberofPumpsinBank
                    elsif pump.autosizedTotalRatedFlowRate.is_initialized
                      pump.autosizedTotalRatedFlowRate.get / pump.numberofPumpsinBank
                    end
                  end
  flow_gpm = OpenStudio.convert(flow_m3_per_s, 'm^3/s', 'gal/min').get

  # Adjustment for clean water pumps requirement:
  # The adjustment is made based on results included
  # in https://www.energy.gov/sites/prod/files/2015/12/f28/Pumps%20ECS%20Final%20Rule.pdf
  # Table 1 summarizes final rule efficiency levels
  # analyzed with corresponding C-values. With the
  # rulemaking adopted TSL/EL2 from the report, it shows
  # about 4.3% of average efficiency improvement, and after
  # considering 25% of the market, about 1.1% of the
  # final average efficiency improvement is estimated.
  #
  # The clean water pump requirement is only
  # applied to pumps with a flow rate of at least 25 gpm
  motor_eff *= 1.011 unless flow_gpm < 25.0

  return [motor_eff, nominal_hp]
end
pump_variable_speed_get_control_type(pump, plant_loop_type, pump_nominal_hp) click to toggle source

Determine type of pump part load control type @note code_sections [90.1-2019_6.5.4.2]

@param pump [OpenStudio::Model::PumpVariableSpeed] OpenStudio pump object @param plant_loop_type [String] Type of plant loop @param pump_nominal_hp [Float] Pump nominal horsepower @return [String] Pump part load control type

# File lib/openstudio-standards/prototypes/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.PumpVariableSpeed.rb, line 11
def pump_variable_speed_get_control_type(pump, plant_loop_type, pump_nominal_hp)
  # Sizing factor to take into account that pumps
  # are typically sized to handle a ~10% pressure
  # increase and ~10% flow increase.
  design_sizing_factor = 1.25

  # Get climate zone
  climate_zone = pump.plantLoop.get.model.getClimateZones.getClimateZone(0)
  climate_zone = "#{climate_zone.institution} 169-#{climate_zone.year}-#{climate_zone.value}"

  # Get nameplate hp threshold:
  # The thresholds below represent the nameplate
  # hp one level lower than the threshold in the
  # code. Motor size from table in section 10 are
  # used as reference.
  case plant_loop_type
    when 'Heating'
      case climate_zone
        when 'ASHRAE 169-2006-7A',
             'ASHRAE 169-2006-7B',
             'ASHRAE 169-2006-8A',
             'ASHRAE 169-2006-8B',
             'ASHRAE 169-2013-7A',
             'ASHRAE 169-2013-7B',
             'ASHRAE 169-2013-8A',
             'ASHRAE 169-2013-8B'
          threshold = 3
        when 'ASHRAE 169-2006-3C',
             'ASHRAE 169-2006-5A',
             'ASHRAE 169-2006-5C',
             'ASHRAE 169-2006-6A',
             'ASHRAE 169-2006-6B',
             'ASHRAE 169-2013-3C',
             'ASHRAE 169-2013-5A',
             'ASHRAE 169-2013-5C',
             'ASHRAE 169-2013-6A',
             'ASHRAE 169-2013-6B'
          threshold = 5
        when 'ASHRAE 169-2006-4A',
             'ASHRAE 169-2006-4C',
             'ASHRAE 169-2006-5B',
             'ASHRAE 169-2013-4A',
             'ASHRAE 169-2013-4C',
             'ASHRAE 169-2013-5B'
          threshold = 7.5
        when 'ASHRAE 169-2006-4B',
             'ASHRAE 169-2013-4B'
          threshold = 10
        when 'ASHRAE 169-2006-2A',
             'ASHRAE 169-2006-2B',
             'ASHRAE 169-2006-3A',
             'ASHRAE 169-2006-3B',
             'ASHRAE 169-2013-2A',
             'ASHRAE 169-2013-2B',
             'ASHRAE 169-2013-3A',
             'ASHRAE 169-2013-3B'
          threshold = 20
        when 'ASHRAE 169-2006-1B',
             'ASHRAE 169-2013-1B'
          threshold = 75
        when 'ASHRAE 169-2006-0A',
             'ASHRAE 169-2006-0B',
             'ASHRAE 169-2006-1A',
             'ASHRAE 169-2013-0A',
             'ASHRAE 169-2013-0B',
             'ASHRAE 169-2013-1A'
          threshold = 150
        else
          OpenStudio.logFree(OpenStudio::Warn, 'openstudio.ashrae_90_1_2019.PumpVariableSpeed', "Pump flow control requirement missing for heating water pumps in climate zone: #{climate_zone}.")
      end
    when 'Cooling'
      case climate_zone
        when 'ASHRAE 169-2006-0A',
             'ASHRAE 169-2006-0B',
             'ASHRAE 169-2006-1A',
             'ASHRAE 169-2006-1B',
             'ASHRAE 169-2006-2B',
             'ASHRAE 169-2013-0A',
             'ASHRAE 169-2013-0B',
             'ASHRAE 169-2013-1A',
             'ASHRAE 169-2013-1B',
             'ASHRAE 169-2013-2B'
          threshold = 1.5
        when 'ASHRAE 169-2006-2A',
             'ASHRAE 169-2006-3B',
             'ASHRAE 169-2013-2A',
             'ASHRAE 169-2013-3B'
          threshold = 2
        when 'ASHRAE 169-2006-3A',
             'ASHRAE 169-2006-3C',
             'ASHRAE 169-2006-4A',
             'ASHRAE 169-2006-4B',
             'ASHRAE 169-2013-3A',
             'ASHRAE 169-2013-3C',
             'ASHRAE 169-2013-4A',
             'ASHRAE 169-2013-4B'
          threshold = 3
        when 'ASHRAE 169-2006-4C',
             'ASHRAE 169-2006-5A',
             'ASHRAE 169-2006-5B',
             'ASHRAE 169-2006-5C',
             'ASHRAE 169-2006-6A',
             'ASHRAE 169-2006-6B',
             'ASHRAE 169-2013-4C',
             'ASHRAE 169-2013-5A',
             'ASHRAE 169-2013-5B',
             'ASHRAE 169-2013-5C',
             'ASHRAE 169-2013-6A',
             'ASHRAE 169-2013-6B'
          threshold = 5
        when 'ASHRAE 169-2006-7A',
             'ASHRAE 169-2006-7B',
             'ASHRAE 169-2006-8A',
             'ASHRAE 169-2006-8B',
             'ASHRAE 169-2013-7A',
             'ASHRAE 169-2013-7B',
             'ASHRAE 169-2013-8A',
             'ASHRAE 169-2013-8B'
          threshold = 10
        else
          OpenStudio.logFree(OpenStudio::Warn, 'openstudio.ashrae_90_1_2019.PumpVariableSpeed', "Pump flow control requirement missing for chilled water pumps in climate zone: #{climate_zone}.")
      end
    else
      OpenStudio.logFree(OpenStudio::Warn, 'openstudio.ashrae_90_1_2019.PumpVariableSpeed', "No pump flow requirement for #{plant_loop_type} plant loops.")
      return false
  end

  return 'VSD DP Reset' if pump_nominal_hp * design_sizing_factor > threshold

  # else
  return 'Riding Curve'
end
set_maximum_fraction_outdoor_air_schedule(air_loop_hvac, oa_control, snc) click to toggle source

Create an economizer maximum OA fraction schedule with For ASHRAE 90.1 2019, a maximum of 75% to reflect damper leakage per PNNL

@param air_loop_hvac [OpenStudio::Model::AirLoopHVAC] HVAC air loop object @param oa_control [OpenStudio::Model::ControllerOutdoorAir] Outdoor air controller object to have this maximum OA fraction schedule @param snc [String] System name

@return [OpenStudio::Model::ScheduleRuleset] Generated maximum outdoor air fraction schedule for later use

# File lib/openstudio-standards/prototypes/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.hvac_systems.rb, line 22
def set_maximum_fraction_outdoor_air_schedule(air_loop_hvac, oa_control, snc)
  max_oa_sch_name = "#{snc}maxOASch"
  max_oa_sch = OpenStudio::Model::ScheduleRuleset.new(air_loop_hvac.model)
  max_oa_sch.setName(max_oa_sch_name)
  max_oa_sch.defaultDaySchedule.setName("#{max_oa_sch_name}Default")
  max_oa_sch.defaultDaySchedule.addValue(OpenStudio::Time.new(0, 24, 0, 0), 0.75)
  oa_control.setMaximumFractionofOutdoorAirSchedule(max_oa_sch)
  max_oa_sch
end
space_daylighted_area_window_width(space) click to toggle source

Determines the method used to extend the daylighted area horizontally next to a window. If the method is ‘fixed’, 2 ft is added to the width of each window. If the method is ‘proportional’, a distance equal to half of the head height of the window is added. If the method is ‘none’, no additional width is added.

@return [String] returns ‘fixed’ or ‘proportional’

# File lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.Space.rb, line 11
def space_daylighted_area_window_width(space)
  method = 'proportional'
  return method
end
space_daylighting_control_required?(space, areas) click to toggle source

Determine if the space requires daylighting controls for toplighting, primary sidelighting, and secondary sidelighting. Defaults to false for all types.

@param space [OpenStudio::Model::Space] the space in question @param areas [Hash] a hash of daylighted areas @return [Array<Bool>] req_top_ctrl, req_pri_ctrl, req_sec_ctrl

# File lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.Space.rb, line 23
def space_daylighting_control_required?(space, areas)
  req_top_ctrl = true
  req_pri_ctrl = true
  req_sec_ctrl = true

  # Get the LPD of the space
  space_lpd_w_per_m2 = space.lightingPowerPerFloorArea

  # Primary Sidelighting
  # Check if the primary sidelit area contains less than 150W of lighting
  if areas['primary_sidelighted_area'] == 0.0
    OpenStudio.logFree(OpenStudio::Debug, 'openstudio.model.Space', "For #{space.name}, primary sidelighting control not required because primary sidelighted area = 0ft2 per 9.4.1.1(e).")
    req_pri_ctrl = false
  elsif areas['primary_sidelighted_area'] * space_lpd_w_per_m2 < 150.0
    OpenStudio.logFree(OpenStudio::Info, 'openstudio.model.Space', "For #{space.name}, primary sidelighting control not required because less than 150W of lighting are present in the primary daylighted area per 9.4.1.1(e).")
    req_pri_ctrl = false
  else
    # Check the size of the windows
    if areas['total_window_area'] < OpenStudio.convert(20.0, 'ft^2', 'm^2').get
      OpenStudio.logFree(OpenStudio::Info, 'openstudio.model.Space', "For #{space.name}, primary sidelighting control not required because there are less than 20ft2 of window per 9.4.1.1(e) Exception 2.")
      req_pri_ctrl = false
    end
  end

  # Secondary Sidelighting
  # Check if the primary and secondary sidelit areas contains less than 300W of lighting
  if areas['secondary_sidelighted_area'] == 0.0
    OpenStudio.logFree(OpenStudio::Debug, 'openstudio.model.Space', "For #{space.name}, secondary sidelighting control not required because secondary sidelighted area = 0ft2 per 9.4.1.1(e).")
    req_sec_ctrl = false
  elsif (areas['primary_sidelighted_area'] + areas['secondary_sidelighted_area']) * space_lpd_w_per_m2 < 300
    OpenStudio.logFree(OpenStudio::Info, 'openstudio.model.Space', "For #{space.name}, secondary sidelighting control not required because less than 300W of lighting are present in the combined primary and secondary daylighted areas per 9.4.1.1(e).")
    req_sec_ctrl = false
  else
    # Check the size of the windows
    if areas['total_window_area'] < OpenStudio.convert(20.0, 'ft^2', 'm^2').get
      OpenStudio.logFree(OpenStudio::Info, 'openstudio.model.Space', "For #{space.name}, secondary sidelighting control not required because there are less than 20ft2 of window per 9.4.1.1(e) Exception 2.")
      req_sec_ctrl = false
    end
  end

  # Toplighting
  # Check if the toplit area contains less than 150W of lighting
  if areas['toplighted_area'] == 0.0
    OpenStudio.logFree(OpenStudio::Debug, 'openstudio.model.Space', "For #{space.name}, toplighting control not required because toplighted area = 0ft2 per 9.4.1.1(f).")
    req_top_ctrl = false
  elsif areas['toplighted_area'] * space_lpd_w_per_m2 < 150
    OpenStudio.logFree(OpenStudio::Info, 'openstudio.model.Space', "For #{space.name}, toplighting control not required because less than 150W of lighting are present in the toplighted area per 9.4.1.1(f).")
    req_top_ctrl = false
  end

  # Exceptions
  if space.spaceType.is_initialized
    case space.spaceType.get.standardsSpaceType.to_s
    # Retail spaces exception (c) to Section 9.4.1.4
    # req_sec_ctrl set to true to create a second reference point
    when 'Core_Retail'
      req_pri_ctrl = false
      req_sec_ctrl = true
    when 'Entry', 'Front_Retail', 'Point_of_Sale'
      req_pri_ctrl = false
      req_sec_ctrl = false
    # Strip mall
    when 'Strip mall - type 1', 'Strip mall - type 2', 'Strip mall - type 3'
      req_pri_ctrl = false
      req_sec_ctrl = false
    # Residential apartments
    when 'Apartment', 'Apartment_topfloor_NS', 'Apartment_topfloor_WE'
      req_top_ctrl = false
      req_pri_ctrl = false
      req_sec_ctrl = false
    end
  end

  return [req_top_ctrl, req_pri_ctrl, req_sec_ctrl]
end
space_daylighting_control_type(space) click to toggle source

Provide the type of daylighting control type

@param space [OpenStudio::Model::Space] OpenStudio Space object return [String] daylighting control type

# File lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.Space.rb, line 197
def space_daylighting_control_type(space)
  return 'ContinuousOff'
end
space_daylighting_fractions_and_windows(space, areas, sorted_windows, sorted_skylights, req_top_ctrl, req_pri_ctrl, req_sec_ctrl) click to toggle source

Determine the fraction controlled by each sensor and which window each sensor should go near.

@param space [OpenStudio::Model::Space] space object @param areas [Hash] a hash of daylighted areas @param sorted_windows [Hash] a hash of windows, sorted by priority @param sorted_skylights [Hash] a hash of skylights, sorted by priority @param req_top_ctrl [Boolean] if toplighting controls are required @param req_pri_ctrl [Boolean] if primary sidelighting controls are required @param req_sec_ctrl [Boolean] if secondary sidelighting controls are required @return [Array] array of 4 items

[sensor 1 fraction, sensor 2 fraction, sensor 1 window, sensor 2 window]
# File lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.Space.rb, line 110
def space_daylighting_fractions_and_windows(space,
                                            areas,
                                            sorted_windows,
                                            sorted_skylights,
                                            req_top_ctrl,
                                            req_pri_ctrl,
                                            req_sec_ctrl)
  sensor_1_frac = 0.0
  sensor_2_frac = 0.0
  sensor_1_window = nil
  sensor_2_window = nil

  # Get the area of the space
  space_area_m2 = space.floorArea

  # get the climate zone
  climate_zone = OpenstudioStandards::Weather.model_get_climate_zone(space.model)

  if req_top_ctrl && req_pri_ctrl && req_sec_ctrl
    # Sensor 1 controls toplighted area
    sensor_1_frac = areas['toplighted_area'] / space_area_m2
    sensor_1_window = sorted_skylights[0]
    # Sensor 2 controls primary + secondary area
    sensor_2_frac = (areas['primary_sidelighted_area'] + areas['secondary_sidelighted_area']) / space_area_m2
    sensor_2_window = sorted_windows[0]
  elsif !req_top_ctrl && req_pri_ctrl && req_sec_ctrl
    # Sensor 1 controls primary area
    sensor_1_frac = areas['primary_sidelighted_area'] / space_area_m2
    sensor_1_window = sorted_windows[0]
    # Sensor 2 controls secondary area
    sensor_2_frac = (areas['secondary_sidelighted_area'] / space_area_m2)
    sensor_2_window = sorted_windows[0]
  elsif req_top_ctrl && !req_pri_ctrl && req_sec_ctrl
    # Sensor 1 controls toplighted area
    sensor_1_frac = areas['toplighted_area'] / space_area_m2
    sensor_1_window = sorted_skylights[0]
    # Sensor 2 controls secondary area
    sensor_2_frac = (areas['secondary_sidelighted_area'] / space_area_m2)
    # sorted_skylights[0] assigned to sensor_2_window so a second reference point is added for top daylighting
    sensor_2_window = sorted_skylights[0]
  elsif req_top_ctrl && !req_pri_ctrl && !req_sec_ctrl
    case climate_zone
      when 'ASHRAE 169-2006-6A',
           'ASHRAE 169-2006-6B',
           'ASHRAE 169-2006-7A',
           'ASHRAE 169-2006-8A',
           'ASHRAE 169-2013-6A',
           'ASHRAE 169-2013-6B',
           'ASHRAE 169-2013-7A',
           'ASHRAE 169-2013-8A'
        # Sensor 1 controls toplighted area
        sensor_1_frac = areas['toplighted_area'] / space_area_m2
        sensor_1_window = sorted_skylights[0]
      else
        # Sensor 1 controls toplighted area
        num_sensors = 2
        sensor_1_frac = areas['toplighted_area'] / space_area_m2 / num_sensors
        sensor_1_window = sorted_skylights[0]
        sensor_2_frac = sensor_1_frac
        sensor_2_window = sensor_1_window
    end
  elsif !req_top_ctrl && req_pri_ctrl && !req_sec_ctrl
    # Sensor 1 controls primary area
    sensor_1_frac = areas['primary_sidelighted_area'] / space_area_m2
    sensor_1_window = sorted_windows[0]
  elsif !req_top_ctrl && !req_pri_ctrl && req_sec_ctrl
    # Sensor 1 controls secondary area
    sensor_1_frac = areas['secondary_sidelighted_area'] / space_area_m2
    sensor_1_window = sorted_windows[0]
  end

  return [sensor_1_frac, sensor_2_frac, sensor_1_window, sensor_2_window]
end
space_daylighting_minimum_input_power_fraction(space) click to toggle source

Provide the minimum input power fraction for continuous dimming daylighting control

@param space [OpenStudio::Model::Space] OpenStudio Space object return [Float] daylighting minimum input power fraction

# File lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.Space.rb, line 206
def space_daylighting_minimum_input_power_fraction(space)
  return 0.2
end
space_infiltration_rate_75_pa(space = nil) click to toggle source

Determine the base infiltration rate at 75 Pa.

@return [Double] the baseline infiltration rate, in cfm/ft^2 defaults to no infiltration.

# File lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.Space.rb, line 188
def space_infiltration_rate_75_pa(space = nil)
  basic_infil_rate_cfm_per_ft2 = 1.0
  return basic_infil_rate_cfm_per_ft2
end
space_occupancy_standby_mode(thermostat) click to toggle source

Modify thermostat schedule to account for a thermostat setback/up

@param thermostat [OpenStudio::Model::ThermostatSetpointDualSetpoint] OpenStudio ThermostatSetpointDualSetpoint object @return [Boolean] returns true if successful, false if not

# File lib/openstudio-standards/prototypes/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.Space.rb, line 40
def space_occupancy_standby_mode(thermostat)
  htg_sch = thermostat.getHeatingSchedule.get
  clg_sch = thermostat.getCoolingSchedule.get

  # Setback heating schedule
  # Setback is 1 deg. F per code requirement
  # Time of the day is arbitrary lack of dynamic occupant modeling
  setup = 1 # deg. F
  htg_sch_mod = { '12' => -1 * OpenStudio.convert(setup, 'R', 'K').get }
  htg_sch_name = "#{htg_sch.name} - occupant standby mode"
  htg_sch_old = thermostat.model.getScheduleRulesetByName(htg_sch_name)
  if htg_sch_old.empty?
    htg_sch_offset = model_offset_schedule_value(htg_sch, htg_sch_mod)
    htg_sch_offset.setName(htg_sch_name)
    thermostat.setHeatingSchedule(htg_sch_offset)
  else
    thermostat.setHeatingSchedule(htg_sch_old.get)
  end

  # Setup cooling schedule
  # Setup is 1 deg. F per code requirement
  # Time of the day is arbitrary lack of dynamic occupant modeling
  setback = 1 # deg. F
  clg_sch_mod = { '12' => OpenStudio.convert(setback, 'R', 'K').get }
  clg_sch_name = "#{clg_sch.name} - occupant standby mode"
  clg_sch_old = thermostat.model.getScheduleRulesetByName(clg_sch_name)
  if clg_sch_old.empty?
    clg_sch_offset = model_offset_schedule_value(clg_sch, clg_sch_mod)
    clg_sch_offset.setName(clg_sch_name)
    thermostat.setCoolingSchedule(clg_sch_offset)
  else
    thermostat.setCoolingSchedule(clg_sch_old.get)
  end

  return true
end
space_occupancy_standby_mode_required?(space) click to toggle source

Determine if a space should be modeled with an occupancy standby mode

@param space [OpenStudio::Model::Space] OpenStudio Space object @return [Boolean] true if occupancy standby mode is to be modeled, false otherwise

# File lib/openstudio-standards/prototypes/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.Space.rb, line 8
def space_occupancy_standby_mode_required?(space)
  # Get space type
  return false if space.spaceType.empty?

  space_type = space.spaceType.get

  # Get standards space type
  return false if space_type.standardsSpaceType.empty?

  std_space_type = space_type.standardsSpaceType.get

  # Space with standby mode are determined based
  # on note H in Std 62.1 and their automatic partial
  # of full off lighting control requirement in 90.1.
  # In 90.1-2019/62.1-2016 this comes down to office
  # spaces (enclosed =< 250 ft2) and conference/meeting
  # and multipurpose rooms.
  # Currently standards doesn't excatly use the 90.1
  # space description so all spaces types that include
  # office/meeting/conference are flagged as having
  # occupant standby mode.
  if std_space_type.downcase.include?('office') || std_space_type.downcase.include?('meeting') || std_space_type.downcase.include?('conference')
    return true
  end

  return false
end
thermal_zone_demand_control_ventilation_limits(thermal_zone) click to toggle source

Determine the area and occupancy level limits for demand control ventilation.

@param thermal_zone [OpenStudio::Model::ThermalZone] the thermal zone @return [Array<Double>] the minimum area, in m^2 and the minimum occupancy density in m^2/person. Returns nil if there is no requirement.

# File lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.ThermalZone.rb, line 46
def thermal_zone_demand_control_ventilation_limits(thermal_zone)
  min_area_ft2 = 500
  min_occ_per_1000_ft2 = 25

  # Convert to SI
  min_area_m2 = OpenStudio.convert(min_area_ft2, 'ft^2', 'm^2').get
  min_occ_per_ft2 = min_occ_per_1000_ft2 / 1000.0
  min_ft2_per_occ = 1.0 / min_occ_per_ft2
  min_m2_per_occ = OpenStudio.convert(min_ft2_per_occ, 'ft^2', 'm^2').get

  return [min_area_m2, min_m2_per_occ]
end
thermal_zone_occupancy_type(thermal_zone) click to toggle source

Determine the thermal zone’s occupancy type category. Options are: residential, nonresidential, publicassembly, retail

@return [String] the occupancy type category @todo Add public assembly building types

# File lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.ThermalZone.rb, line 9
def thermal_zone_occupancy_type(thermal_zone)
  occ_type = if OpenstudioStandards::ThermalZone.thermal_zone_residential?(thermal_zone)
               'residential'
             else
               'nonresidential'
             end

  # Based on the space type that
  # represents a majority of the zone.
  space_type = OpenstudioStandards::ThermalZone.thermal_zone_get_space_type(thermal_zone)
  if space_type.is_initialized
    space_type = space_type.get
    bldg_type = space_type.standardsBuildingType
    if bldg_type.is_initialized
      bldg_type = bldg_type.get
      case bldg_type
      when 'Retail', 'StripMall', 'SuperMarket'
        occ_type = 'retail'
        # when 'SomeBuildingType'
        # @todo add publicassembly building types
        # occ_type = 'publicassembly'
      end
    end
  end

  # OpenStudio::logFree(OpenStudio::Info, "openstudio.Standards.ThermalZone", "For #{self.name}, occupancy type = #{occ_type}.")

  return occ_type
end
water_heater_mixed_additional_search_criteria(water_heater_mixed, search_criteria) click to toggle source

Add additional search criteria for water heater lookup efficiency.

@param water_heater_mixed [OpenStudio::Model::WaterHeaterMixed] water heater mixed object @param search_criteria [Hash] search criteria for looking up water heater data @return [Hash] updated search criteria

# File lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.WaterHeaterMixed.rb, line 7
def water_heater_mixed_additional_search_criteria(water_heater_mixed, search_criteria)
  search_criteria['draw_profile'] = 'medium' # assumption; could be based on inputs
  return search_criteria
end
zone_hvac_component_vestibule_heating_control_required?(zone_hvac_component) click to toggle source

Determine if vestibule heating control is required. Required for 90.1-2019 per 6.4.3.9.

@ref [References::ASHRAE9012019] 6.4.3.9 @param zone_hvac_component [OpenStudio::Model::ZoneHVACComponent] zone hvac component @return [Boolean] returns true if successful, false if not

# File lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.ZoneHVACComponent.rb, line 10
def zone_hvac_component_vestibule_heating_control_required?(zone_hvac_component)
  # Ensure that the equipment is assigned to a thermal zone
  if zone_hvac_component.thermalZone.empty?
    OpenStudio.logFree(OpenStudio::Warn, 'openstudio.model.ZoneHVACComponent', "For #{zone_hvac_component.name}: equipment is not assigned to a thermal zone, cannot apply vestibule heating control.")
    return false
  end

  # Only applies to equipment that is in vestibule zones
  return true if OpenstudioStandards::ThermalZone.thermal_zone_vestibule?(zone_hvac_component.thermalZone.get)

  # If here, vestibule heating control not required
  return false
end
zone_hvac_model_standby_mode_occupancy_control(zone_hvac_component) click to toggle source

Add occupant standby controls to zone equipment Currently, the controls consists of cycling the fan during the occupant standby mode hours

@param zone_hvac_component OpenStudio zonal equipment object @return [Boolean] true if sucessful, false otherwise

# File lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2019/ashrae_90_1_2019.ZoneHVACComponent.rb, line 30
def zone_hvac_model_standby_mode_occupancy_control(zone_hvac_component)
  # Ensure that the equipment is assigned to a thermal zone
  if zone_hvac_component.thermalZone.empty?
    OpenStudio.logFree(OpenStudio::Warn, 'openstudio.model.ZoneHVACComponent', "For #{zone_hvac_component.name}: equipment is not assigned to a thermal zone, cannot apply vestibule heating control.")
    return true
  end

  # Get supply fan
  # Only Fan:OnOff can cycle
  fan = zone_hvac_component.supplyAirFan
  return true unless fan.to_FanOnOff.is_initialized

  fan = fan.to_FanOnOff.get
  # Set fan operating schedule during assumed occupant standby mode time to 0 so the fan can cycle
  # ZoneHVACFourPipeFanCoil has it optional, PTAC/PTHP starting a 3.5.0 is required
  new_sch = model_set_schedule_value(OpenStudio::Model::OptionalSchedule.new(zone_hvac_component.supplyAirFanOperatingModeSchedule).get, '12' => 0)
  zone_hvac_component.setSupplyAirFanOperatingModeSchedule(new_sch) unless new_sch == true

  return true
end