Class: Honeybee::ServiceHotWaterAbridged

Inherits:
ModelObject show all
Defined in:
lib/honeybee/load/service_hot_water.rb,
lib/to_openstudio/load/service_hot_water.rb,
lib/from_openstudio/load/service_hot_water.rb

Constant Summary collapse

@@max_target_temp = 
60
@@max_temp_schedule = 
nil
@@shw_connections = 
{}
@@shw_rates = 
{}
@@hp_deadband = 
4
@@sys_count = 
1

Instance Attribute Summary

Attributes inherited from ModelObject

#errors, #openstudio_object, #warnings

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from ModelObject

#allowable_types, clean_identifier, clean_name, #initialize, #method_missing, read_from_disk, truncate

Constructor Details

This class inherits a constructor from Honeybee::ModelObject

Dynamic Method Handling

This class handles dynamic methods through the method_missing method in the class Honeybee::ModelObject

Class Method Details

.from_load(load, floor_area) ⇒ Object 



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# File 'lib/from_openstudio/load/service_hot_water.rb', line 38

def self.from_load(load, floor_area)
    # create an empty hash
    hash = {}
    hash[:type] = 'ServiceHotWaterAbridged'
    # set hash values from OpenStudio Object
    hash[:identifier] = clean_name(load.nameString)
    load_def = load.waterUseEquipmentDefinition
    # units of peak flow rate are m3/s
    peak_flow = load_def.peakFlowRate
    # unit for flow per area is L/h-m2 (m3/s = 3600000 L/h)
    hash[:flow_per_area] = (peak_flow * 3600000) / floor_area
    unless load.flowRateFractionSchedule.empty? 
        schedule = load.flowRateFractionSchedule.get
        hash[:schedule] = schedule.nameString
    end

    hash
end

Instance Method Details

#add_hot_water_plants(openstudio_model, shw_hashes) ⇒ Object 



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# File 'lib/to_openstudio/load/service_hot_water.rb', line 55

def add_hot_water_plants(openstudio_model, shw_hashes)
  # add district hot water loops to supply all of the shw_connections
  shw_hashes.each do |shw_hash|
    unless @@shw_rates[shw_hash[:identifier]].nil?
      # create the plant loop
      hot_water_plant = OpenStudio::Model::PlantLoop.new(openstudio_model)
      hot_water_plant.setName('SHW Loop ' + shw_hash[:identifier])
      hot_water_plant.setMaximumLoopTemperature(@@max_target_temp)
      hot_water_plant.setMinimumLoopTemperature(10)  # default value in C from OpenStudio Application

      # edit the sizing information to be for a hot water loop
      loop_sizing = hot_water_plant.sizingPlant()
      loop_sizing.setLoopType('Heating')
      loop_sizing.setDesignLoopExitTemperature(@@max_target_temp)  
      loop_sizing.setLoopDesignTemperatureDifference(5)  # default value in C from OpenStudio Application

      # add a setpoint manager for the loop
      hot_sch = @@max_temp_schedule
      if @@max_temp_schedule.nil?
        hot_sch_name = @@max_target_temp.to_s + 'C Hot Water'
        hot_sch = create_constant_schedule(openstudio_model, hot_sch_name, @@max_target_temp)
      end
      sp_manager = OpenStudio::Model::SetpointManagerScheduled.new(openstudio_model, hot_sch)
      sp_manager.addToNode(hot_water_plant.supplyOutletNode())

      # add a constant speed pump for the loop
      hot_water_pump = OpenStudio::Model::PumpConstantSpeed.new(openstudio_model)
      hot_water_pump.setName('SHW Pump' + @@sys_count.to_s)
      hot_water_pump.setRatedPumpHead(29891)  # default value in Pa from OpenStudio Application
      hot_water_pump.setMotorEfficiency(0.9)  # default value from OpenStudio Application
      hot_water_pump.addToNode(hot_water_plant.supplyInletNode())

      eq_type = shw_hash[:equipment_type]
      if eq_type == 'Default_District_SHW'
        # add a district heating system to supply the heat for the loop
        district_hw = OpenStudio::Model::WaterHeaterMixed.new(openstudio_model)
        district_hw.setName('Ideal Service Hot Water Heater')
        district_hw.setHeaterFuelType('DistrictHeating')
        district_hw.setOffCycleParasiticFuelType('DistrictHeating')
        district_hw.setOnCycleParasiticFuelType('DistrictHeating')
        district_hw.setHeaterThermalEfficiency(1.0)
        district_hw.setHeaterMaximumCapacity(1000000)
        district_hw.setTankVolume(0)
        district_hw.setHeaterControlType('Modulate')
        target_sch_name = '22C Ambient Condition'
        target_sch = create_constant_schedule(openstudio_model, target_sch_name, 22)
        district_hw.setAmbientTemperatureSchedule(target_sch)
        district_hw.setOffCycleLossCoefficienttoAmbientTemperature(0)
        district_hw.setOnCycleLossCoefficienttoAmbientTemperature(0)
        hot_water_plant.addSupplyBranchForComponent(district_hw)
        # try to minimize the impact of the pump as much as possible
        hot_water_pump.setEndUseSubcategory('Water Systems')
        hot_water_pump.setMotorEfficiency(0.9)
      else
        # add a water heater to supply the heat for the loop
        heater = OpenStudio::Model::WaterHeaterMixed.new(openstudio_model)
        if eq_type == 'Electric_WaterHeater' || eq_type == 'HeatPump_WaterHeater' || eq_type == 'Electric_TanklessHeater'
          heater.setHeaterFuelType('Electricity')
          heater.setOffCycleParasiticFuelType('Electricity')
          heater.setOnCycleParasiticFuelType('Electricity')
        end

        # set the water heater efficiency
        if eq_type == 'HeatPump_WaterHeater'
          heater.setHeaterThermalEfficiency(1.0)
        elsif shw_hash[:heater_efficiency].nil?
          if eq_type == 'Electric_WaterHeater' || eq_type == 'Electric_TanklessHeater'
            heater.setHeaterThermalEfficiency(1.0)
          else
            heater.setHeaterThermalEfficiency(0.8)
          end
        else
          heater.setHeaterThermalEfficiency(shw_hash[:heater_efficiency])
        end

        # set the ambient condition of the water tank
        to_thermal_zone = false
        unless shw_hash[:ambient_condition].nil?
          if shw_hash[:ambient_condition].is_a? Numeric
            target_sch_name = shw_hash[:ambient_condition].to_s + 'C Ambient Condition'
            target_sch = create_constant_schedule(
              openstudio_model, target_sch_name, shw_hash[:ambient_condition])
            heater.setAmbientTemperatureSchedule(target_sch)
          else
            source_zone_ref = openstudio_model.getThermalZoneByName(shw_hash[:ambient_condition])
            unless source_zone_ref.empty?
              source_zone = source_zone_ref.get
              heater.setAmbientTemperatureThermalZone(source_zone)
            end
            heater.setAmbientTemperatureIndicator('ThermalZone')
            to_thermal_zone = true
          end
        else
          target_sch_name = '22C Ambient Condition'
          target_sch = create_constant_schedule(openstudio_model, target_sch_name, 22)
          heater.setAmbientTemperatureSchedule(target_sch)
        end

        # set the ambient loss coefficient
        if to_thermal_zone
          unless shw_hash[:ambient_loss_coefficient].nil?
            heater.setOffCycleLossFractiontoThermalZone(
              shw_hash[:ambient_loss_coefficient])
            heater.setOnCycleLossFractiontoThermalZone(
              shw_hash[:ambient_loss_coefficient])
          else
            heater.setOffCycleLossFractiontoThermalZone(6)
            heater.setOnCycleLossFractiontoThermalZone(6)
          end
        else
          unless shw_hash[:ambient_loss_coefficient].nil?
            heater.setOffCycleLossCoefficienttoAmbientTemperature(
              shw_hash[:ambient_loss_coefficient])
            heater.setOnCycleLossCoefficienttoAmbientTemperature(
              shw_hash[:ambient_loss_coefficient])
          else
            heater.setOffCycleLossCoefficienttoAmbientTemperature(6)
            heater.setOnCycleLossCoefficienttoAmbientTemperature(6)
          end
        end

        # set the capactiy and and controls of the water heater
        heater.setHeaterMaximumCapacity(1000000)
        if eq_type == 'Gas_TanklessHeater' || eq_type == 'Electric_TanklessHeater'
          heater.setName('SHW Tankless WaterHeater' + @@sys_count.to_s)
          heater.setTankVolume(0)
          heater.setHeaterControlType('Modulate')
          heater.setOffCycleLossCoefficienttoAmbientTemperature(0)
          heater.setOnCycleLossCoefficienttoAmbientTemperature(0)
        else
          heater.setName('SHW WaterHeater' + @@sys_count.to_s)
          heater.setTankVolume(@@shw_rates[shw_hash[:identifier]])
        end

        # add it to the loop
        hot_water_plant.addSupplyBranchForComponent(heater)
        
        # if it's a heat pump system, then add the pump
        if eq_type == 'HeatPump_WaterHeater'
          # create a coil for the heat pump
          heat_pump = OpenStudio::Model::CoilWaterHeatingAirToWaterHeatPump.new(openstudio_model)
          heat_pump.setName('SHW HPWH DX Coil' + @@sys_count.to_s)
          if shw_hash[:heater_efficiency].nil?
            heat_pump.setRatedCOP(3.5)
          else
            heat_pump.setRatedCOP(shw_hash[:heater_efficiency])
          end

          # add a fan for the heat pump system
          fan = OpenStudio::Model::FanOnOff.new(openstudio_model)
          fan.setName('HPWH Fan' + @@sys_count.to_s)
          fan.setEndUseSubcategory('Water Systems')
          setpt_sch = create_constant_schedule(
            openstudio_model, 'HPWH Setpoint' + @@sys_count.to_s, @@max_target_temp + (@@hp_deadband * 2))
          inlet_sch = create_constant_schedule(
            openstudio_model, 'Inlet Air Mixer Fraction' + @@sys_count.to_s, 0.2)

          # add a water heater to supply the heat for the loop
          heat_sys = OpenStudio::Model::WaterHeaterHeatPump.new(
            openstudio_model, heat_pump, heater, fan, setpt_sch, inlet_sch)
          heat_sys.setDeadBandTemperatureDifference(@@hp_deadband)
          
          source_zone_ref = openstudio_model.getThermalZoneByName(shw_hash[:ambient_condition])
          unless source_zone_ref.empty?
            source_zone = source_zone_ref.get
            heat_sys.addToThermalZone(source_zone)
          end
          heat_sys.setName('SHW WaterHeater HeatPump' + @@sys_count.to_s)
        end
      end

      # add all of the water use connections to the loop and total the capacity
      @@shw_connections[shw_hash[:identifier]].each do |shw_conn|
        hot_water_plant.addDemandBranchForComponent(shw_conn)
      end
      @@sys_count = @@sys_count + 1
    end
  end
end

#defaults ⇒ Object 



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# File 'lib/honeybee/load/service_hot_water.rb', line 37

def defaults
  @@schema[:components][:schemas][:ServiceHotWaterAbridged][:properties]
end

#find_existing_openstudio_object(openstudio_model) ⇒ Object 



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# File 'lib/to_openstudio/load/service_hot_water.rb', line 49

def find_existing_openstudio_object(openstudio_model)
  model_shw = openstudio_model.getWaterUseEquipmentByName(@hash[:identifier])
  return model_shw.get unless model_shw.empty?
  nil
end

#shw_connections ⇒ Object 



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# File 'lib/to_openstudio/load/service_hot_water.rb', line 45

def shw_connections
  @@shw_connections
end

#to_openstudio(openstudio_model, os_space, shw_name) ⇒ Object 



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# File 'lib/to_openstudio/load/service_hot_water.rb', line 235

def to_openstudio(openstudio_model, os_space, shw_name)
  # if there's no name, assume that we're using the default district water heater
  if shw_name.nil?
    shw_name = 'default_district_shw'
  end

  # create water use equipment + connection and set identifier
  os_shw_def = OpenStudio::Model::WaterUseEquipmentDefinition.new(openstudio_model)
  os_shw = OpenStudio::Model::WaterUseEquipment.new(os_shw_def)
  unique_id = @hash[:identifier] + '..' + os_space.nameString[0...-6]
  os_shw_def.setName(unique_id)
  os_shw.setName(unique_id)

  # assign the flow of water
  total_flow = (@hash[:flow_per_area].to_f * os_space.floorArea) / 3600000
  os_shw_def.setPeakFlowRate(total_flow)
  os_shw_def.setEndUseSubcategory('General')
  if @@shw_rates[shw_name].nil?
    @@shw_rates[shw_name] = 0
  end
  @@shw_rates[shw_name] = @@shw_rates[shw_name] + (total_flow * 3600)

  # assign schedule
  shw_schedule = openstudio_model.getScheduleByName(@hash[:schedule])
  unless shw_schedule.empty?
    shw_schedule_object = shw_schedule.get
    os_shw.setFlowRateFractionSchedule(shw_schedule_object)
  end

  # assign the hot water temperature
  target_temp = defaults[:target_temperature][:default]
  if @hash[:target_temperature]
    target_temp = @hash[:target_temperature]
  end
  target_sch_name = target_temp.to_s + 'C Hot Water'
  target_water_sch = create_constant_schedule(openstudio_model, target_sch_name, target_temp)
  os_shw_def.setTargetTemperatureSchedule(target_water_sch)

  # create the hot water connection with same temperature as target temperature
  os_shw_conn = OpenStudio::Model::WaterUseConnections.new(openstudio_model)
  os_shw_conn.addWaterUseEquipment(os_shw)
  os_shw_conn.setHotWaterSupplyTemperatureSchedule(target_water_sch)
  if target_temp > @@max_target_temp
    @@max_target_temp = target_temp
    @@max_temp_schedule = target_water_sch
  end
  if @@shw_connections[shw_name].nil?
    @@shw_connections[shw_name] = []
  end
  @@shw_connections[shw_name] << os_shw_conn

  # assign sensible fraction if it exists
  sens_fract = defaults[:sensible_fraction][:default]
  if @hash[:sensible_fraction]
    sens_fract = @hash[:sensible_fraction]
  end
  sens_sch_name = sens_fract.to_s + ' Hot Water Sensible Fraction'
  sens_fract_sch = create_constant_schedule(openstudio_model, sens_sch_name, sens_fract)
  os_shw_def.setSensibleFractionSchedule(sens_fract_sch)

  # assign latent fraction if it exists
  lat_fract = defaults[:latent_fraction][:default]
  if @hash[:latent_fraction]
    lat_fract = @hash[:latent_fraction]
  end
  lat_sch_name = lat_fract.to_s + ' Hot Water Latent Fraction'
  lat_fract_sch = create_constant_schedule(openstudio_model, lat_sch_name, lat_fract)
  os_shw_def.setLatentFractionSchedule(lat_fract_sch)

  # assign the service hot water to the space
  os_shw.setSpace(os_space)

  os_shw
end