class ZEAEDGMultifamily

This class holds methods that apply the “standard” assumptions for Zero Energy Advanced Energy Design Guide for Multifamily Buildings to a given model. @ref [References::ZEAEDGMultifamily]

Attributes

template[R]

Public Class Methods

new() click to toggle source
Calls superclass method ASHRAE901::new
# File lib/openstudio-standards/standards/ashrae_90_1/ze_aedg_multifamily/ze_aedg_multifamily.rb, line 8
def initialize
  super()
  @template = 'ZE AEDG Multifamily'
  load_standards_database
end

Public Instance Methods

air_loop_hvac_apply_energy_recovery_ventilator_efficiency(erv, erv_type: 'ERV', heat_exchanger_type: 'Rotary') click to toggle source

Apply efficiency values to the erv

@param erv [OpenStudio::Model::HeatExchangerAirToAirSensibleAndLatent] erv to apply efficiency values @param erv_type [String] erv type ERV or HRV @param heat_exchanger_type [String] heat exchanger type Rotary or Plate @return [OpenStudio::Model::HeatExchangerAirToAirSensibleAndLatent] erv to apply efficiency values

# File lib/openstudio-standards/standards/ashrae_90_1/ze_aedg_multifamily/ze_aedg_multifamily.AirLoopHVAC.rb, line 777
def air_loop_hvac_apply_energy_recovery_ventilator_efficiency(erv, erv_type: 'ERV', heat_exchanger_type: 'Rotary')
  if heat_exchanger_type == 'Plate'
    # based on Zehnder ComfoAir
    if erv_type == 'HRV'
      erv.setSensibleEffectivenessat100HeatingAirFlow(0.865)
      erv.setLatentEffectivenessat100HeatingAirFlow(0.0)
      erv.setSensibleEffectivenessat75HeatingAirFlow(0.887)
      erv.setLatentEffectivenessat75HeatingAirFlow(0.0)
      erv.setSensibleEffectivenessat100CoolingAirFlow(0.865)
      erv.setLatentEffectivenessat100CoolingAirFlow(0.0)
      erv.setSensibleEffectivenessat75CoolingAirFlow(0.887)
      erv.setLatentEffectivenessat75CoolingAirFlow(0.0)
    else
      erv.setSensibleEffectivenessat100HeatingAirFlow(0.755)
      erv.setLatentEffectivenessat100HeatingAirFlow(0.564)
      erv.setSensibleEffectivenessat75HeatingAirFlow(0.791)
      erv.setLatentEffectivenessat75HeatingAirFlow(0.625)
      erv.setSensibleEffectivenessat100CoolingAirFlow(0.755)
      erv.setLatentEffectivenessat100CoolingAirFlow(0.564)
      erv.setSensibleEffectivenessat75CoolingAirFlow(0.791)
      erv.setLatentEffectivenessat75CoolingAirFlow(0.625)
    end
  else
    if erv_type == 'HRV'
      erv.setSensibleEffectivenessat100HeatingAirFlow(0.75)
      erv.setLatentEffectivenessat100HeatingAirFlow(0.0)
      erv.setSensibleEffectivenessat75HeatingAirFlow(0.79)
      erv.setLatentEffectivenessat75HeatingAirFlow(0.0)
      erv.setSensibleEffectivenessat100CoolingAirFlow(0.75)
      erv.setLatentEffectivenessat100CoolingAirFlow(0.0)
      erv.setSensibleEffectivenessat75CoolingAirFlow(0.78)
      erv.setLatentEffectivenessat75CoolingAirFlow(0.0)
    else
      erv.setSensibleEffectivenessat100HeatingAirFlow(0.75)
      erv.setLatentEffectivenessat100HeatingAirFlow(0.74)
      erv.setSensibleEffectivenessat75HeatingAirFlow(0.79)
      erv.setLatentEffectivenessat75HeatingAirFlow(0.79)
      erv.setSensibleEffectivenessat100CoolingAirFlow(0.75)
      erv.setLatentEffectivenessat100CoolingAirFlow(0.74)
      erv.setSensibleEffectivenessat75CoolingAirFlow(0.78)
      erv.setLatentEffectivenessat75CoolingAirFlow(0.78)
    end
  end

  return erv
end
air_loop_hvac_dcv_required_when_erv(air_loop_hvac) click to toggle source

Determine if the standard has an exception for demand control ventilation when an energy recovery device is present. DCV and an ERV may be used in conjunction.

@param air_loop_hvac [OpenStudio::Model::AirLoopHVAC] air loop @return [Boolean] returns true if required, false if not

# File lib/openstudio-standards/standards/ashrae_90_1/ze_aedg_multifamily/ze_aedg_multifamily.AirLoopHVAC.rb, line 282
def air_loop_hvac_dcv_required_when_erv(air_loop_hvac)
  dcv_required_when_erv_present = true
  return dcv_required_when_erv_present
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/ze_aedg_multifamily/ze_aedg_multifamily.AirLoopHVAC.rb, line 271
def air_loop_hvac_demand_control_ventilation_limits(air_loop_hvac)
  min_oa_without_economizer_cfm = 1500.0 # half the 90.1-2013 requirement
  min_oa_with_economizer_cfm = 375.0 # half the 90.1-2013 requirement
  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. @note Same as 90.1-2013

@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/ze_aedg_multifamily/ze_aedg_multifamily.AirLoopHVAC.rb, line 10
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 # No OA system

  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'
    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 169-2006-5C',
         '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 169-2013-5C',
         'ASHRAE 169-2013-6B',
         'ASHRAE 169-2013-7A',
         'ASHRAE 169-2013-7B',
         'ASHRAE 169-2013-8A',
         'ASHRAE 169-2013-8B'
      drybulb_limit_f = 75.0
    when 'ASHRAE 169-2006-5A',
         'ASHRAE 169-2006-6A',
         'ASHRAE 169-2013-5A',
         'ASHRAE 169-2013-6A'
      drybulb_limit_f = 70.0
    end
  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

Same as 90.1-2013 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/ze_aedg_multifamily/ze_aedg_multifamily.AirLoopHVAC.rb, line 98
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. @note Same as 90.1-2016

@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/ze_aedg_multifamily/ze_aedg_multifamily.AirLoopHVAC.rb, line 485
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.standards.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
    case climate_zone
    when 'ASHRAE 169-2006-3B',
         'ASHRAE 169-2006-3C',
         'ASHRAE 169-2006-4B',
         'ASHRAE 169-2006-4C',
         'ASHRAE 169-2006-5B',
         'ASHRAE 169-2013-3B',
         'ASHRAE 169-2013-3C',
         'ASHRAE 169-2013-4B',
         'ASHRAE 169-2013-4C',
         'ASHRAE 169-2013-5B'
      erv_cfm = nil
    when 'ASHRAE 169-2006-0B',
         'ASHRAE 169-2006-1B',
         'ASHRAE 169-2006-2B',
         'ASHRAE 169-2006-5C',
         'ASHRAE 169-2013-0B',
         'ASHRAE 169-2013-1B',
         'ASHRAE 169-2013-2B',
         'ASHRAE 169-2013-5C'
      if pct_oa < 0.5
        erv_cfm = nil
      elsif pct_oa >= 0.5 && pct_oa < 0.6
        erv_cfm = 26_000
      elsif pct_oa >= 0.6 && pct_oa < 0.7
        erv_cfm = 12_000
      elsif pct_oa >= 0.7 && pct_oa < 0.8
        erv_cfm = 5000
      elsif pct_oa >= 0.8
        erv_cfm = 4000
      end
    when 'ASHRAE 169-2006-6B',
         'ASHRAE 169-2013-6B'
      if pct_oa < 0.1
        erv_cfm = nil
      elsif pct_oa >= 0.1 && pct_oa < 0.2
        erv_cfm = 28_000
      elsif pct_oa >= 0.2 && pct_oa < 0.3
        erv_cfm = 26_500
      elsif pct_oa >= 0.3 && pct_oa < 0.4
        erv_cfm = 11_000
      elsif pct_oa >= 0.4 && pct_oa < 0.5
        erv_cfm = 5500
      elsif pct_oa >= 0.5 && pct_oa < 0.6
        erv_cfm = 4500
      elsif pct_oa >= 0.6 && pct_oa < 0.7
        erv_cfm = 3500
      elsif pct_oa >= 0.7 && pct_oa < 0.8
        erv_cfm = 2500
      elsif pct_oa >= 0.8
        erv_cfm = 1500
      end
    when 'ASHRAE 169-2006-0A',
         'ASHRAE 169-2006-1A',
         'ASHRAE 169-2006-2A',
         'ASHRAE 169-2006-3A',
         'ASHRAE 169-2006-4A',
         'ASHRAE 169-2006-5A',
         'ASHRAE 169-2006-6A',
         'ASHRAE 169-2013-0A',
         'ASHRAE 169-2013-1A',
         'ASHRAE 169-2013-2A',
         'ASHRAE 169-2013-3A',
         'ASHRAE 169-2013-4A',
         'ASHRAE 169-2013-5A',
         'ASHRAE 169-2013-6A'
      if pct_oa < 0.1
        erv_cfm = nil
      elsif pct_oa >= 0.1 && pct_oa < 0.2
        erv_cfm = 26_000
      elsif pct_oa >= 0.2 && pct_oa < 0.3
        erv_cfm = 16_000
      elsif pct_oa >= 0.3 && pct_oa < 0.4
        erv_cfm = 5500
      elsif pct_oa >= 0.4 && pct_oa < 0.5
        erv_cfm = 4500
      elsif pct_oa >= 0.5 && pct_oa < 0.6
        erv_cfm = 3500
      elsif pct_oa >= 0.6 && pct_oa < 0.7
        erv_cfm = 2000
      elsif pct_oa >= 0.7 && pct_oa < 0.8
        erv_cfm = 1000
      elsif pct_oa >= 0.8
        erv_cfm = 120
      end
    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'
      if pct_oa < 0.1
        erv_cfm = nil
      elsif pct_oa >= 0.1 && pct_oa < 0.2
        erv_cfm = 4500
      elsif pct_oa >= 0.2 && pct_oa < 0.3
        erv_cfm = 4000
      elsif pct_oa >= 0.3 && pct_oa < 0.4
        erv_cfm = 2500
      elsif pct_oa >= 0.4 && pct_oa < 0.5
        erv_cfm = 1000
      elsif pct_oa >= 0.5 && pct_oa < 0.6
        erv_cfm = 140
      elsif pct_oa >= 0.6 && pct_oa < 0.7
        erv_cfm = 120
      elsif pct_oa >= 0.7 && pct_oa < 0.8
        erv_cfm = 100
      elsif pct_oa >= 0.8
        erv_cfm = 80
      end
    end
  else
    # Table 6.5.6.1-2, above 8000 hrs
    case climate_zone
    when 'ASHRAE 169-2006-3C',
         'ASHRAE 169-2013-3C'
      erv_cfm = nil
    when 'ASHRAE 169-2006-0B',
         'ASHRAE 169-2006-1B',
         'ASHRAE 169-2006-2B',
         'ASHRAE 169-2006-3B',
         'ASHRAE 169-2006-4C',
         'ASHRAE 169-2006-5C',
         'ASHRAE 169-2013-0B',
         'ASHRAE 169-2013-1B',
         'ASHRAE 169-2013-2B',
         'ASHRAE 169-2013-3B',
         'ASHRAE 169-2013-4C',
         'ASHRAE 169-2013-5C'
      if pct_oa < 0.2
        erv_cfm = nil
      elsif pct_oa >= 0.2 && pct_oa < 0.3
        erv_cfm = 19_500
      elsif pct_oa >= 0.3 && pct_oa < 0.4
        erv_cfm = 9000
      elsif pct_oa >= 0.4 && pct_oa < 0.5
        erv_cfm = 5000
      elsif pct_oa >= 0.5 && pct_oa < 0.6
        erv_cfm = 4000
      elsif pct_oa >= 0.6 && pct_oa < 0.7
        erv_cfm = 3000
      elsif pct_oa >= 0.7 && pct_oa < 0.8
        erv_cfm = 1500
      elsif pct_oa >= 0.8
        erv_cfm = 120
      end
    when 'ASHRAE 169-2006-0A',
         'ASHRAE 169-2006-1A',
         'ASHRAE 169-2006-2A',
         'ASHRAE 169-2006-3A',
         'ASHRAE 169-2006-4B',
         'ASHRAE 169-2006-5B',
         'ASHRAE 169-2013-0A',
         'ASHRAE 169-2013-1A',
         'ASHRAE 169-2013-2A',
         'ASHRAE 169-2013-3A',
         'ASHRAE 169-2013-4B',
         'ASHRAE 169-2013-5B'
      if pct_oa < 0.1
        erv_cfm = nil
      elsif pct_oa >= 0.1 && pct_oa < 0.2
        erv_cfm = 2500
      elsif pct_oa >= 0.2 && pct_oa < 0.3
        erv_cfm = 2000
      elsif pct_oa >= 0.3 && pct_oa < 0.4
        erv_cfm = 1000
      elsif pct_oa >= 0.4 && pct_oa < 0.5
        erv_cfm = 500
      elsif pct_oa >= 0.5 && pct_oa < 0.6
        erv_cfm = 140
      elsif pct_oa >= 0.6 && pct_oa < 0.7
        erv_cfm = 120
      elsif pct_oa >= 0.7 && pct_oa < 0.8
        erv_cfm = 100
      elsif pct_oa >= 0.8
        erv_cfm = 80
      end
    when 'ASHRAE 169-2006-4A',
         'ASHRAE 169-2006-5A',
         '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 169-2013-5A',
         'ASHRAE 169-2013-6A',
         'ASHRAE 169-2013-6B',
         'ASHRAE 169-2013-7A',
         'ASHRAE 169-2013-7B',
         'ASHRAE 169-2013-8A',
         'ASHRAE 169-2013-8B'
      if pct_oa < 0.1
        erv_cfm = nil
      elsif pct_oa >= 0.1 && pct_oa < 0.2
        erv_cfm = 200
      elsif pct_oa >= 0.2 && pct_oa < 0.3
        erv_cfm = 130
      elsif pct_oa >= 0.3 && pct_oa < 0.4
        erv_cfm = 100
      elsif pct_oa >= 0.4 && pct_oa < 0.5
        erv_cfm = 80
      elsif pct_oa >= 0.5 && pct_oa < 0.6
        erv_cfm = 70
      elsif pct_oa >= 0.6 && pct_oa < 0.7
        erv_cfm = 60
      elsif pct_oa >= 0.7 && pct_oa < 0.8
        erv_cfm = 50
      elsif pct_oa >= 0.8
        erv_cfm = 40
      end
    end
  end

  return erv_cfm
end
air_loop_hvac_energy_recovery_ventilator_heat_exchanger_type(air_loop_hvac) click to toggle source

Determine whether to use a Plate-Frame or Rotary Wheel style ERV depending on air loop outdoor air flow rate Defaults to Rotary.

@param air_loop_hvac [OpenStudio::Model::AirLoopHVAC] air loop @return [String] the erv type

# File lib/openstudio-standards/standards/ashrae_90_1/ze_aedg_multifamily/ze_aedg_multifamily.AirLoopHVAC.rb, line 738
def air_loop_hvac_energy_recovery_ventilator_heat_exchanger_type(air_loop_hvac)
  # Get the OA system
  if air_loop_hvac.airLoopHVACOutdoorAirSystem.is_initialized
    oa_system = air_loop_hvac.airLoopHVACOutdoorAirSystem.get
    controller_oa = oa_system.getControllerOutdoorAir
  else
    OpenStudio.logFree(OpenStudio::Info, 'openstudio.nrel_zne_ready_2017.AirLoopHVAC', "For #{air_loop_hvac.name}, ERV type not applicable because it has no OA intake.")
    return false
  end

  # Get the minimum OA flow rate
  if controller_oa.maximumOutdoorAirFlowRate.is_initialized
    max_oa_flow_m3_per_s = controller_oa.maximumOutdoorAirFlowRate.get
  elsif controller_oa.autosizedMaximumOutdoorAirFlowRate.is_initialized
    max_oa_flow_m3_per_s = controller_oa.autosizedMaximumOutdoorAirFlowRate.get
  else
    OpenStudio.logFree(OpenStudio::Warn, 'openstudio.nrel_zne_ready_2017.AirLoopHVAC', "For #{controller_oa.name}: maximum OA flow rate is not available, cannot determine ERV type.")
    return false
  end
  max_oa_flow_cfm = OpenStudio.convert(max_oa_flow_m3_per_s, 'm^3/s', 'cfm').get

  # Use a 500 cfm threshold
  if max_oa_flow_cfm < 500.0
    heat_exchanger_type = 'Plate'
    OpenStudio.logFree(OpenStudio::Info, 'openstudio.nrel_zne_ready_2017.AirLoopHVAC', "For #{air_loop_hvac.name}, maximum outdoor air flow rate is less than 500 cfm, assuming a plate and frame heat exchanger.")
  else
    heat_exchanger_type = 'Rotary'
    OpenStudio.logFree(OpenStudio::Info, 'openstudio.nrel_zne_ready_2017.AirLoopHVAC', "For #{air_loop_hvac.name}, maximum outdoor air flow rate is greater than 500 cfm, assuming a rotary wheel heat exchanger.")
  end

  return heat_exchanger_type
end
air_loop_hvac_energy_recovery_ventilator_required?(air_loop_hvac, climate_zone) click to toggle source

Same as Standards method but with no DCV exception Check if ERV is required on this airloop.

@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/ze_aedg_multifamily/ze_aedg_multifamily.AirLoopHVAC.rb, line 422
def air_loop_hvac_energy_recovery_ventilator_required?(air_loop_hvac, climate_zone)
  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}, ERV not applicable because it has no OA intake.")
    return false
  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 false
  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 false
  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

  # Determine the airflow limit
  erv_cfm = air_loop_hvac_energy_recovery_ventilator_flow_limit(air_loop_hvac, climate_zone, pct_oa)

  # Determine if an ERV is required
  if erv_cfm.nil?
    OpenStudio.logFree(OpenStudio::Info, 'openstudio.standards.AirLoopHVAC', "For #{air_loop_hvac.name}, ERV not required based on #{(pct_oa * 100).round}% OA flow, design supply air flow of #{dsn_flow_cfm.round}cfm, and climate zone #{climate_zone}.")
    erv_required = false
  elsif dsn_flow_cfm < erv_cfm
    OpenStudio.logFree(OpenStudio::Info, 'openstudio.standards.AirLoopHVAC', "For #{air_loop_hvac.name}, ERV not required based on #{(pct_oa * 100).round}% OA flow, design supply air flow of #{dsn_flow_cfm.round}cfm, and climate zone #{climate_zone}. Does not exceed minimum flow requirement of #{erv_cfm}cfm.")
    erv_required = false
  else
    OpenStudio.logFree(OpenStudio::Info, 'openstudio.standards.AirLoopHVAC', "For #{air_loop_hvac.name}, ERV required based on #{(pct_oa * 100).round}% OA flow, design supply air flow of #{dsn_flow_cfm.round}cfm, and climate zone #{climate_zone}. Exceeds minimum flow requirement of #{erv_cfm}cfm.")
    erv_required = true
  end

  return erv_required
end
air_loop_hvac_energy_recovery_ventilator_type(air_loop_hvac, climate_zone) click to toggle source

Determine whether to apply an Energy Recovery Ventilator ‘ERV’ or a Heat Recovery Ventilator ‘HRV’ depending on the climate zone Defaults to ERV.

@param air_loop_hvac [OpenStudio::Model::AirLoopHVAC] air loop @param climate_zone [String] ASHRAE climate zone, e.g. ‘ASHRAE 169-2013-4A’ @return [String] the erv type

# File lib/openstudio-standards/standards/ashrae_90_1/ze_aedg_multifamily/ze_aedg_multifamily.AirLoopHVAC.rb, line 728
def air_loop_hvac_energy_recovery_ventilator_type(air_loop_hvac, climate_zone)
  erv_type = 'ERV'
  return erv_type
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. @note same as 90.1-2013 All economizers must be integrated in 90.1-2013

@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/ze_aedg_multifamily/ze_aedg_multifamily.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. @note Same as 90.1-2013

@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/ze_aedg_multifamily/ze_aedg_multifamily.AirLoopHVAC.rb, line 293
def air_loop_hvac_motorized_oa_damper_limits(air_loop_hvac, climate_zone)
  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'
    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 Same as 90.1-2013

@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/ze_aedg_multifamily/ze_aedg_multifamily.AirLoopHVAC.rb, line 186
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

  # Not required for systems that require an ERV
  if air_loop_hvac_energy_recovery?(air_loop_hvac)
    OpenStudio.logFree(OpenStudio::Info, 'openstudio.standards.AirLoopHVAC', "For #{air_loop_hvac.name}: multizone vav optimization is not required because the system has Energy Recovery.")
    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. @note Same as 90.1-2013 90.1-2013 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/ze_aedg_multifamily/ze_aedg_multifamily.AirLoopHVAC.rb, line 330
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_supply_air_temperature_reset_required?(air_loop_hvac, climate_zone) click to toggle source

Determine if the system required supply air temperature (SAT) reset. @note Same as 90.1-2013 For 90.1-2013, SAT reset requirements are based on climate zone.

@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/ze_aedg_multifamily/ze_aedg_multifamily.AirLoopHVAC.rb, line 351
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

  case climate_zone
  when 'ASHRAE 169-2006-0A',
       'ASHRAE 169-2006-1A',
       'ASHRAE 169-2006-2A',
       'ASHRAE 169-2006-3A',
       'ASHRAE 169-2013-0A',
       'ASHRAE 169-2013-1A',
       'ASHRAE 169-2013-2A',
       'ASHRAE 169-2013-3A'
    OpenStudio.logFree(OpenStudio::Info, 'openstudio.standards.AirLoopHVAC', "For #{air_loop_hvac.name}: Supply air temperature reset is not required per 6.5.3.4 Exception 1, the system is located in climate zone #{climate_zone}.")
    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_loop_hvac_unoccupied_threshold() click to toggle source

Default occupancy fraction threshold for determining if the spaces on the air loop are occupied @return [Double] threshold at which the air loop space are considered unoccupied

# File lib/openstudio-standards/standards/ashrae_90_1/ze_aedg_multifamily/ze_aedg_multifamily.AirLoopHVAC.rb, line 412
def air_loop_hvac_unoccupied_threshold
  return 0.05
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/ze_aedg_multifamily/ze_aedg_multifamily.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
                        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 = true) 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/ze_aedg_multifamily/ze_aedg_multifamily.AirTerminalSingleDuctVAVReheat.rb, line 10
def air_terminal_single_duct_vav_reheat_minimum_damper_position(air_terminal_single_duct_vav_reheat, has_ddc = true)
  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
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 per 90.1-2013 6.5.2.2

@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/ze_aedg_multifamily/ze_aedg_multifamily.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/ze_aedg_multifamily/ze_aedg_multifamily.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/ze_aedg_multifamily/ze_aedg_multifamily.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/ze_aedg_multifamily/ze_aedg_multifamily.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 90.1-2013, 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/ze_aedg_multifamily/ze_aedg_multifamily.FanVariableVolume.rb, line 27
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'
                           110_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 90.1-2013, 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/ze_aedg_multifamily/ze_aedg_multifamily.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', 'evap'
               0.25
             end

  return hp_limit
end
heat_exchanger_air_to_air_sensible_and_latent_apply_effectiveness(heat_exchanger_air_to_air_sensible_and_latent) click to toggle source

Sets the minimum effectiveness of the heat exchanger

# File lib/openstudio-standards/standards/ashrae_90_1/ze_aedg_multifamily/ze_aedg_multifamily.HeatExchangerSensLat.rb, line 5
def heat_exchanger_air_to_air_sensible_and_latent_apply_effectiveness(heat_exchanger_air_to_air_sensible_and_latent)
  # Assumed to be sensible and latent at all flow
  heat_exchanger_type = heat_exchanger_air_to_air_sensible_and_latent.heatExchangerType

  if heat_exchanger_type == 'Plate'
    heat_exchanger_air_to_air_sensible_and_latent.setSensibleEffectivenessat100HeatingAirFlow(0.755)
    heat_exchanger_air_to_air_sensible_and_latent.setLatentEffectivenessat100HeatingAirFlow(0.564)
    heat_exchanger_air_to_air_sensible_and_latent.setSensibleEffectivenessat75HeatingAirFlow(0.791)
    heat_exchanger_air_to_air_sensible_and_latent.setLatentEffectivenessat75HeatingAirFlow(0.625)
    heat_exchanger_air_to_air_sensible_and_latent.setSensibleEffectivenessat100CoolingAirFlow(0.755)
    heat_exchanger_air_to_air_sensible_and_latent.setLatentEffectivenessat100CoolingAirFlow(0.564)
    heat_exchanger_air_to_air_sensible_and_latent.setSensibleEffectivenessat75CoolingAirFlow(0.791)
    heat_exchanger_air_to_air_sensible_and_latent.setLatentEffectivenessat75CoolingAirFlow(0.625)
    heat_exchanger_air_to_air_sensible_and_latent.setNominalElectricPower(0.0)
  else # Rotary
    heat_exchanger_air_to_air_sensible_and_latent.setSensibleEffectivenessat100HeatingAirFlow(0.75)
    heat_exchanger_air_to_air_sensible_and_latent.setLatentEffectivenessat100HeatingAirFlow(0.74)
    heat_exchanger_air_to_air_sensible_and_latent.setSensibleEffectivenessat75HeatingAirFlow(0.79)
    heat_exchanger_air_to_air_sensible_and_latent.setLatentEffectivenessat75HeatingAirFlow(0.79)
    heat_exchanger_air_to_air_sensible_and_latent.setSensibleEffectivenessat100CoolingAirFlow(0.75)
    heat_exchanger_air_to_air_sensible_and_latent.setLatentEffectivenessat100CoolingAirFlow(0.74)
    heat_exchanger_air_to_air_sensible_and_latent.setSensibleEffectivenessat75CoolingAirFlow(0.78)
    heat_exchanger_air_to_air_sensible_and_latent.setLatentEffectivenessat75CoolingAirFlow(0.78)
  end

  OpenStudio.logFree(OpenStudio::Info, 'openstudio.ze_aedg_multifamily.HeatExchangerAirToAirSensibleAndLatent', "For #{heat_exchanger_air_to_air_sensible_and_latent.name}, set sensible and latent effectiveness to #{heat_exchanger_type} values.")

  return true
end
heat_exchanger_air_to_air_sensible_and_latent_prototype_default_fan_efficiency() click to toggle source

Default fan efficiency assumption for the prm added fan power

@return [Double] default fan efficiency

# File lib/openstudio-standards/prototypes/ashrae_90_1/ze_aedg_multifamily/ze_aedg_multifamily.HeatExchangerAirToAirSensibleAndLatent.rb, line 7
def heat_exchanger_air_to_air_sensible_and_latent_prototype_default_fan_efficiency
  default_fan_efficiency = 0.55
  return default_fan_efficiency
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/ze_aedg_multifamily/ze_aedg_multifamily.rb, line 18
def load_standards_database(data_directories = [])
  super([__dir__] + data_directories)
end
model_apply_hvac_efficiency_standard(model, climate_zone, apply_controls: true) click to toggle source

Applies the HVAC parts of the template to all objects in the model using the the template specified in the model.

# File lib/openstudio-standards/standards/ashrae_90_1/ze_aedg_multifamily/ze_aedg_multifamily.Model.rb, line 5
def model_apply_hvac_efficiency_standard(model, climate_zone, apply_controls: true)
  sql_db_vars_map = {}

  OpenStudio.logFree(OpenStudio::Info, 'openstudio.ze_aedg_multifamily.Model', "Started applying HVAC efficiency standards for #{template} template.")

  # Air Loop Controls
  if apply_controls.nil? || apply_controls == true
    model.getAirLoopHVACs.sort.each { |obj| air_loop_hvac_apply_standard_controls(obj, climate_zone) unless air_loop_hvac_unitary_system?(obj) }
  end

  # Plant Loop Controls
  if apply_controls.nil? || apply_controls == true
    model.getPlantLoops.sort.each { |obj| plant_loop_apply_standard_controls(obj, climate_zone) }
  end

  # Zone HVAC Controls
  model.getZoneHVACComponents.sort.each { |obj| zone_hvac_component_apply_standard_controls(obj) }

  ##### Apply equipment efficiencies

  # Fans
  model.getFanVariableVolumes.sort.each { |obj| fan_apply_standard_minimum_motor_efficiency(obj, fan_brake_horsepower(obj)) }
  model.getFanConstantVolumes.sort.each { |obj| fan_apply_standard_minimum_motor_efficiency(obj, fan_brake_horsepower(obj)) }
  model.getFanOnOffs.sort.each { |obj| fan_apply_standard_minimum_motor_efficiency(obj, fan_brake_horsepower(obj)) }
  model.getFanZoneExhausts.sort.each { |obj| fan_apply_standard_minimum_motor_efficiency(obj, fan_brake_horsepower(obj)) }
  model.getZoneHVACComponents.sort.each { |obj| zone_hvac_component_apply_prm_baseline_fan_power(obj) }

  # Pumps
  model.getPumpConstantSpeeds.sort.each { |obj| pump_apply_standard_minimum_motor_efficiency(obj) }
  model.getPumpVariableSpeeds.sort.each { |obj| pump_apply_standard_minimum_motor_efficiency(obj) }
  model.getHeaderedPumpsConstantSpeeds.sort.each { |obj| pump_apply_standard_minimum_motor_efficiency(obj) }
  model.getHeaderedPumpsVariableSpeeds.sort.each { |obj| pump_apply_standard_minimum_motor_efficiency(obj) }
  model.getPlantLoops.sort.each { |obj| plant_loop_apply_prm_baseline_pumping_type(obj) unless plant_loop_swh_loop?(obj) }

  # Unitary HPs
  # set DX HP coils before DX clg coils because when DX HP coils need to first
  # pull the capacities of their paired DX clg coils, and this does not work
  # correctly if the DX clg coil efficiencies have been set because they are renamed.
  model.getCoilHeatingDXSingleSpeeds.sort.each { |obj| sql_db_vars_map = coil_heating_dx_single_speed_apply_efficiency_and_curves(obj, sql_db_vars_map) }

  # Unitary ACs
  model.getCoilCoolingDXTwoSpeeds.sort.each { |obj| sql_db_vars_map = coil_cooling_dx_two_speed_apply_efficiency_and_curves(obj, sql_db_vars_map) }
  model.getCoilCoolingDXSingleSpeeds.sort.each { |obj| sql_db_vars_map = coil_cooling_dx_single_speed_apply_efficiency_and_curves(obj, sql_db_vars_map) }

  # WSHPs
  # set WSHP heating coils before cooling coils to get cooling coil capacities before they are renamed
  model.getCoilHeatingWaterToAirHeatPumpEquationFits.sort.each { |obj| sql_db_vars_map = coil_heating_water_to_air_heat_pump_apply_efficiency_and_curves(obj, sql_db_vars_map) }
  model.getCoilCoolingWaterToAirHeatPumpEquationFits.sort.each { |obj| sql_db_vars_map = coil_cooling_water_to_air_heat_pump_apply_efficiency_and_curves(obj, sql_db_vars_map) }

  # Chillers
  clg_tower_objs = model.getCoolingTowerSingleSpeeds
  model.getChillerElectricEIRs.sort.each { |obj| chiller_electric_eir_apply_efficiency_and_curves(obj, clg_tower_objs) }

  # Boilers
  model.getBoilerHotWaters.sort.each { |obj| boiler_hot_water_apply_efficiency_and_curves(obj) }

  # Water Heaters
  model.getWaterHeaterMixeds.sort.each { |obj| water_heater_mixed_apply_efficiency(obj) }

  # Cooling Towers
  model.getCoolingTowerSingleSpeeds.sort.each { |obj| cooling_tower_single_speed_apply_efficiency_and_curves(obj) }
  model.getCoolingTowerTwoSpeeds.sort.each { |obj| cooling_tower_two_speed_apply_efficiency_and_curves(obj) }
  model.getCoolingTowerVariableSpeeds.sort.each { |obj| cooling_tower_variable_speed_apply_efficiency_and_curves(obj) }

  # Fluid Coolers
  model.getFluidCoolerSingleSpeeds.sort.each { |obj| fluid_cooler_apply_minimum_power_per_flow(obj, equipment_type: 'Dry Cooler') }
  model.getFluidCoolerTwoSpeeds.sort.each { |obj| fluid_cooler_apply_minimum_power_per_flow(obj, equipment_type: 'Dry Cooler') }
  model.getEvaporativeFluidCoolerSingleSpeeds.sort.each { |obj| fluid_cooler_apply_minimum_power_per_flow(obj, equipment_type: 'Closed Cooling Tower') }
  model.getEvaporativeFluidCoolerTwoSpeeds.sort.each { |obj| fluid_cooler_apply_minimum_power_per_flow(obj, equipment_type: 'Closed Cooling Tower') }

  # ERVs
  model.getHeatExchangerAirToAirSensibleAndLatents.each { |obj| heat_exchanger_air_to_air_sensible_and_latent_apply_effectiveness(obj) }

  # Gas Heaters
  model.getCoilHeatingGass.sort.each { |obj| coil_heating_gas_apply_efficiency_and_curves(obj) }

  OpenStudio.logFree(OpenStudio::Info, 'openstudio.ze_aedg_multifamily.Model', "Finished applying HVAC efficiency standards for #{template} template.")
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 NREL ZNE Ready 2017.

@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/ze_aedg_multifamily/ze_aedg_multifamily.hvac_systems.rb, line 9
def model_cw_loop_cooling_tower_fan_type(model)
  fan_type = 'Variable Speed Fan'
  return fan_type
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/prototypes/ashrae_90_1/ze_aedg_multifamily/ze_aedg_multifamily.Model.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. Same as 90.1-2013, which 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/ze_aedg_multifamily/ze_aedg_multifamily.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/ze_aedg_multifamily/ze_aedg_multifamily.Model.elevators.rb, line 10
def model_elevator_lighting_pct_incandescent(model)
  pct_incandescent = 0.0 # 100% LED
  return pct_incandescent
end
plant_loop_apply_prm_baseline_chilled_water_pumping_type(plant_loop) click to toggle source

Applies the chilled water pumping controls to the loop based on Appendix G.

@param plant_loop [OpenStudio::Model::PlantLoop] chilled water loop @return [Boolean] returns true if successful, false if not

# File lib/openstudio-standards/standards/ashrae_90_1/ze_aedg_multifamily/ze_aedg_multifamily.PlantLoop.rb, line 8
def plant_loop_apply_prm_baseline_chilled_water_pumping_type(plant_loop)
  pri_control_type = 'VSD DP Reset'
  sec_control_type = 'VSD DP Reset'
  has_secondary_pump = false

  # Modify all the secondary pumps
  plant_loop.demandComponents.each do |sc|
    if sc.to_PumpVariableSpeed.is_initialized
      pump = sc.to_PumpVariableSpeed.get
      pump_variable_speed_set_control_type(pump, sec_control_type)
      has_secondary_pump = true
    elsif sc.to_HeaderedPumpsVariableSpeed.is_initialized
      pump = sc.to_HeaderedPumpsVariableSpeed.get
      headered_pumps_variable_speed_set_control_type(pump, control_type)
      has_secondary_pump = true
    end
  end

  # Primary is constant flow if primary/secondary setup
  pri_control_type = 'Constant Flow' if has_secondary_pump

  # Modify all the primary pumps
  plant_loop.supplyComponents.each do |sc|
    if sc.to_PumpVariableSpeed.is_initialized
      pump = sc.to_PumpVariableSpeed.get
      pump_variable_speed_set_control_type(pump, pri_control_type)
    elsif sc.to_HeaderedPumpsVariableSpeed.is_initialized
      pump = sc.to_HeaderedPumpsVariableSpeed.get
      headered_pumps_variable_speed_set_control_type(pump, control_type)
    end
  end

  # Report out the pumping type
  unless pri_control_type.nil?
    OpenStudio.logFree(OpenStudio::Info, 'openstudio.standards.AirLoopHVAC', "For #{plant_loop.name}, primary pump type is #{pri_control_type}.")
  end

  if has_secondary_pump
    OpenStudio.logFree(OpenStudio::Info, 'openstudio.standards.AirLoopHVAC', "For #{plant_loop.name}, secondary pump type is #{sec_control_type}.")
  end

  return true
end
plant_loop_apply_prm_baseline_hot_water_pumping_type(plant_loop) click to toggle source

Applies the hot water pumping controls to the loop

# File lib/openstudio-standards/standards/ashrae_90_1/ze_aedg_multifamily/ze_aedg_multifamily.PlantLoop.rb, line 53
def plant_loop_apply_prm_baseline_hot_water_pumping_type(plant_loop)
  control_type = 'VSD DP Reset'

  # Modify all the primary pumps
  plant_loop.supplyComponents.each do |sc|
    if sc.to_PumpVariableSpeed.is_initialized
      pump = sc.to_PumpVariableSpeed.get
      pump_variable_speed_set_control_type(pump, control_type)
    end
  end

  # Report out the pumping type
  unless control_type.nil?
    OpenStudio.logFree(OpenStudio::Info, 'openstudio.standards.PlantLoop', "For #{plant_loop.name}, pump type is #{control_type}.")
  end

  return true
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/ze_aedg_multifamily/ze_aedg_multifamily.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/ze_aedg_multifamily/ze_aedg_multifamily.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'] < 0.01
    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'] < 0.01
    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'] < 0.01
    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

  return [req_top_ctrl, req_pri_ctrl, req_sec_ctrl]
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/ze_aedg_multifamily/ze_aedg_multifamily.Space.rb, line 87
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

  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)
    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]
  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_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/ze_aedg_multifamily/ze_aedg_multifamily.Space.rb, line 144
def space_infiltration_rate_75_pa(space = nil)
  basic_infil_rate_cfm_per_ft2 = 0.5 # Half of 90.1-2013
  return basic_infil_rate_cfm_per_ft2
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/ze_aedg_multifamily/ze_aedg_multifamily.ThermalZone.rb, line 11
def thermal_zone_demand_control_ventilation_limits(thermal_zone)
  min_area_ft2 = 500
  min_occ_per_1000_ft2 = 12 # half of 90.1-2013

  # 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
zone_hvac_component_prm_baseline_fan_efficacy() click to toggle source

default fan efficiency for small zone hvac fans, in watts per cfm

@return [Double] fan efficiency in watts per cfm

# File lib/openstudio-standards/standards/ashrae_90_1/ze_aedg_multifamily/ze_aedg_multifamily.ZoneHVACComponent.rb, line 7
def zone_hvac_component_prm_baseline_fan_efficacy
  fan_efficacy_w_per_cfm = 0.65
  return fan_efficacy_w_per_cfm
end