Class: ASHRAE9012004

Inherits:
ASHRAE901 show all
Defined in:
lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2004/ashrae_90_1_2004.rb,
lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2004/ashrae_90_1_2004.Model.rb,
lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2004/ashrae_90_1_2004.Space.rb,
lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2004/ashrae_90_1_2004.PlantLoop.rb,
lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2004/ashrae_90_1_2004.AirLoopHVAC.rb,
lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2004/ashrae_90_1_2004.ThermalZone.rb,
lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2004/ashrae_90_1_2004.FanVariableVolume.rb,
lib/openstudio-standards/prototypes/ashrae_90_1/ashrae_90_1_2004/ashrae_90_1_2004.AirTerminalSingleDuctVAVReheat.rb

Overview

This class holds methods that apply ASHRAE 90.1-2004 to a given model.

Technical References:

Constant Summary collapse

@@template =

rubocop:disable Style/ClassVars

'90.1-2004'

Instance Attribute Summary collapse

Model collapse

Space collapse

PlantLoop collapse

AirLoopHVAC collapse

ThermalZone collapse

FanVariableVolume collapse

AirTerminalSingleDuctVAVReheat collapse

Instance Method Summary collapse

Constructor Details

#initializeASHRAE9012004

Returns a new instance of ASHRAE9012004.


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# File 'lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2004/ashrae_90_1_2004.rb', line 9

def initialize
  super()
  @template = @@template
  load_standards_database
end

Instance Attribute Details

#templateObject (readonly)

Returns the value of attribute template


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# File 'lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2004/ashrae_90_1_2004.rb', line 7

def template
  @template
end

Instance Method Details

#air_loop_hvac_demand_control_ventilation_limits(air_loop_hvac) ⇒ Array<Double>

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. are zero for both types.

Returns:

  • (Array<Double>)
    min_oa_without_economizer_cfm, min_oa_with_economizer_cfm

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# File 'lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2004/ashrae_90_1_2004.AirLoopHVAC.rb', line 76

def air_loop_hvac_demand_control_ventilation_limits(air_loop_hvac)
  min_oa_without_economizer_cfm = 3000
  min_oa_with_economizer_cfm = 0
  return [min_oa_without_economizer_cfm, min_oa_with_economizer_cfm]
end

#air_loop_hvac_enable_supply_air_temperature_reset_delta(air_loop_hvac) ⇒ Double

Determines supply air temperature (SAT) temperature. For 90.1-2007, 10 delta-F (R)

Returns:

  • (Double)

    the SAT reset amount (R)


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# File 'lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2004/ashrae_90_1_2004.AirLoopHVAC.rb', line 126

def air_loop_hvac_enable_supply_air_temperature_reset_delta(air_loop_hvac)
  sat_reset_r = 10
  return sat_reset_r
end

#air_loop_hvac_energy_recovery_ventilator_flow_limit(air_loop_hvac, climate_zone, pct_oa) ⇒ Double

Determine the airflow limits that govern whether or not an ERV is required. Based on climate zone and % OA. if nil, ERV is never required.

Returns:

  • (Double)

    the flow rate above which an ERV is required.


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# File 'lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2004/ashrae_90_1_2004.AirLoopHVAC.rb', line 135

def air_loop_hvac_energy_recovery_ventilator_flow_limit(air_loop_hvac, climate_zone, pct_oa)
  erv_cfm = if pct_oa < 0.7
              nil
            else
              # @Todo: Add exceptions (eg: e. cooling systems in climate zones 3C, 4C, 5B, 5C, 6B, 7 and 8 | d. Heating systems in climate zones 1 to 3)
              5000
            end

  return erv_cfm
end

#air_loop_hvac_motorized_oa_damper_limits(air_loop_hvac, climate_zone) ⇒ Array<Double>

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

Returns:

  • (Array<Double>)
    minimum_oa_flow_cfm, maximum_stories

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# File 'lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2004/ashrae_90_1_2004.AirLoopHVAC.rb', line 94

def air_loop_hvac_motorized_oa_damper_limits(air_loop_hvac, climate_zone)
  case climate_zone
  when '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',
    minimum_oa_flow_cfm = 300
    maximum_stories = 999 # Any number of stories
  else
    minimum_oa_flow_cfm = 300
    maximum_stories = 3
  end

  return [minimum_oa_flow_cfm, maximum_stories]
end

#air_loop_hvac_prm_baseline_economizer_required?(air_loop_hvac, climate_zone) ⇒ Bool

Determine if an economizer is required per the PRM.

Returns:

  • (Bool)

    returns true if required, false if not


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# File 'lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2004/ashrae_90_1_2004.AirLoopHVAC.rb', line 8

def air_loop_hvac_prm_baseline_economizer_required?(air_loop_hvac, climate_zone)
  economizer_required = false

  # A big number of ft2 as the minimum requirement
  infinity_ft2 = 999_999_999_999
  min_int_area_served_ft2 = infinity_ft2
  min_ext_area_served_ft2 = infinity_ft2

  # Determine the minimum capacity that requires an economizer
  case climate_zone
  when 'ASHRAE 169-2006-1A',
      'ASHRAE 169-2006-1B',
      'ASHRAE 169-2006-2A',
      'ASHRAE 169-2006-3A',
      'ASHRAE 169-2006-4A'
    min_int_area_served_ft2 = infinity_ft2 # No requirement
    min_ext_area_served_ft2 = infinity_ft2 # No requirement
  when 'ASHRAE 169-2006-2B',
      'ASHRAE 169-2006-5A',
      'ASHRAE 169-2006-6A',
      'ASHRAE 169-2006-7A',
      'ASHRAE 169-2006-7B',
      'ASHRAE 169-2006-8A',
      'ASHRAE 169-2006-8B'
    min_int_area_served_ft2 = 15_000
    min_ext_area_served_ft2 = infinity_ft2 # No requirement
  when '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'
    min_int_area_served_ft2 = 10_000
    min_ext_area_served_ft2 = 25_000
  end

  # Check whether the system requires an economizer by comparing
  # the system capacity to the minimum capacity.
  min_int_area_served_m2 = OpenStudio.convert(min_int_area_served_ft2, 'ft^2', 'm^2').get
  min_ext_area_served_m2 = OpenStudio.convert(min_ext_area_served_ft2, 'ft^2', 'm^2').get

  # Get the interior and exterior area served
  int_area_served_m2 = air_loop_hvac_floor_area_served_interior_zones(air_loop_hvac)
  ext_area_served_m2 = air_loop_hvac_floor_area_served_exterior_zones(air_loop_hvac)

  # Check the floor area exception
  if int_area_served_m2 < min_int_area_served_m2 && ext_area_served_m2 < min_ext_area_served_m2
    if min_int_area_served_ft2 == infinity_ft2 && min_ext_area_served_ft2 == infinity_ft2
      OpenStudio.logFree(OpenStudio::Info, 'openstudio.standards.AirLoopHVAC', "For #{air_loop_hvac.name}: Economizer not required for climate zone #{climate_zone}.")
    else
      OpenStudio.logFree(OpenStudio::Info, 'openstudio.standards.AirLoopHVAC', "For #{air_loop_hvac.name}: Economizer not required for because the interior area served of #{int_area_served_m2} ft2 < minimum of #{min_int_area_served_m2} and the perimeter area served of #{ext_area_served_m2} ft2 < minimum of #{min_ext_area_served_m2} for climate zone #{climate_zone}.")
    end
    return economizer_required
  end

  # If here, economizer required
  economizer_required = true
  OpenStudio.logFree(OpenStudio::Info, 'openstudio.standards.AirLoopHVAC', "For #{air_loop_hvac.name}: Economizer required for the performance rating method baseline.")

  return economizer_required
end

#air_loop_hvac_single_zone_controls_num_stages(air_loop_hvac, climate_zone) ⇒ Integer

Determine the number of stages that should be used as controls for single zone DX systems. 90.1-2004 requires 1 stage.

Returns:

  • (Integer)

    the number of stages: 0, 1, 2


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# File 'lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2004/ashrae_90_1_2004.AirLoopHVAC.rb', line 117

def air_loop_hvac_single_zone_controls_num_stages(air_loop_hvac, climate_zone)
  num_stages = 1
  return num_stages
end

#air_loop_hvac_vav_damper_action(air_loop_hvac) ⇒ String

Determine whether the VAV damper control is single maximum or dual maximum control. Single Maximum for 90.1-2004.

Returns:

  • (String)

    the damper control type: Single Maximum, Dual Maximum


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# File 'lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2004/ashrae_90_1_2004.AirLoopHVAC.rb', line 86

def air_loop_hvac_vav_damper_action(air_loop_hvac)
  damper_action = 'Single Maximum'
  return damper_action
end

#air_terminal_single_duct_vav_reheat_apply_initial_prototype_damper_position(air_terminal_single_duct_vav_reheat, building_type, zone_oa_per_area) ⇒ Bool

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

Parameters:

  • zone_oa_per_area (Double)

    the zone outdoor air per area, m^3/s

Returns:

  • (Bool)

    returns true if successful, false if not


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# File 'lib/openstudio-standards/prototypes/ashrae_90_1/ashrae_90_1_2004/ashrae_90_1_2004.AirTerminalSingleDuctVAVReheat.rb', line 11

def air_terminal_single_duct_vav_reheat_apply_initial_prototype_damper_position(air_terminal_single_duct_vav_reheat, building_type, zone_oa_per_area)
  vav_name = air_terminal_single_duct_vav_reheat.name.get
  min_damper_position = 0.3

  # High OA zones
  # Determine whether or not to use the high minimum guess.
  # Cutoff was determined by correlating apparent minimum guesses
  # to OA rates in prototypes since not well documented in papers.
  if zone_oa_per_area > 0.001 # 0.001 m^3/s*m^2 = .196 cfm/ft2

    min_damper_position = if building_type == 'Outpatient' || building_type == 'Hospital'
                            1.0
                          else
                            0.7
                          end
  end

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

  return true
end

#fan_variable_volume_part_load_fan_power_limitation_hp_limit(fan_variable_volume) ⇒ Double

TODO:

AddRef

The threhold horsepower below which part load control is not required. 15 nameplate HP threshold is equivalent to motors with input powers of 9.9 HP per TSD

Parameters:

  • fan_variable_volume (OpenStudio::Model::FanVariableVolume)

    the fan

Returns:

  • (Double)

    the limit, in horsepower. Return nil for no limit by default.


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# File 'lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2004/ashrae_90_1_2004.FanVariableVolume.rb', line 10

def fan_variable_volume_part_load_fan_power_limitation_hp_limit(fan_variable_volume)
  hp_limit = 9.9
  return hp_limit
end

#model_get_climate_zone_set_from_list(model, possible_climate_zone_sets) ⇒ Object

Determine which climate zone to use. Uses the most specific climate zone set for most climate zones, except for ClimateZone 3, which uses the least specific climate zone.


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# File 'lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2004/ashrae_90_1_2004.Model.rb', line 8

def model_get_climate_zone_set_from_list(model, possible_climate_zone_sets)
  climate_zone_set = if possible_climate_zone_sets.include? 'ClimateZone 3'
                       possible_climate_zone_sets.sort.last
                     else
                       possible_climate_zone_sets.sort.first
                     end
  return climate_zone_set
end

#plant_loop_apply_prm_baseline_chilled_water_pumping_type(plant_loop) ⇒ Object

Set the primary and secondary pumping control types for the chilled water loop, as specified in Appendix G.


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# File 'lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2004/ashrae_90_1_2004.PlantLoop.rb', line 6

def plant_loop_apply_prm_baseline_chilled_water_pumping_type(plant_loop)
  # Determine the pumping type.
  minimum_area_ft2 = 120_000

  # Determine the area served
  area_served_m2 = plant_loop_total_floor_area_served(plant_loop)
  area_served_ft2 = OpenStudio.convert(area_served_m2, 'm^2', 'ft^2').get

  # Determine the primary pump type
  pri_control_type = 'Constant Flow'

  # Determine the secondary pump type
  sec_control_type = 'Riding Curve'
  if area_served_ft2 > minimum_area_ft2
    sec_control_type = 'VSD No Reset'
  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

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

  # 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_pump_variable_speed_set_control_type(pump, control_type)
    end
  end

  # 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)
    elsif sc.to_HeaderedPumpsVariableSpeed.is_initialized
      pump = sc.to_HeaderedPumpsVariableSpeed.get
      headered_pump_variable_speed_set_control_type(pump, control_type)
    end
  end

  return true
end

#space_infiltration_rate_75_pa(space) ⇒ Double

Determine the base infiltration rate at 75 PA.

defaults to no infiltration.

Returns:

  • (Double)

    the baseline infiltration rate, in cfm/ft^2


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# File 'lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2004/ashrae_90_1_2004.Space.rb', line 8

def space_infiltration_rate_75_pa(space)
  basic_infil_rate_cfm_per_ft2 = 1.8
  return basic_infil_rate_cfm_per_ft2
end

#thermal_zone_demand_control_ventilation_limits(thermal_zone) ⇒ Array<Double>

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

and the minimum occupancy density in m^2/person. Returns nil if there is no requirement.

Parameters:

  • thermal_zone (OpenStudio::Model::ThermalZone)

    the thermal zone

Returns:

  • (Array<Double>)

    the minimum area, in m^2


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# File 'lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2004/ashrae_90_1_2004.ThermalZone.rb', line 11

def thermal_zone_demand_control_ventilation_limits(thermal_zone)
  min_area_ft2 = nil # No minimum area
  min_occ_per_1000_ft2 = 100

  # Convert to SI
  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_ft2, min_m2_per_occ]
end