honeybee_energy.load.hotwater module

Complete definition of service hot water, including schedule and load.

class honeybee_energy.load.hotwater.ServiceHotWater(identifier, flow_per_area, schedule, target_temperature=60, sensible_fraction=0.2, latent_fraction=0.05)[source]

Bases: _LoadBase

A complete definition of service hot water, including schedules and load.

Parameters

  • identifier – Text string for a unique ServiceHotWater ID. Must be < 100 characters and not contain any EnergyPlus special characters. This will be used to identify the object across a model and in the exported IDF.

  • flow_per_area – A numerical value for the total volume flow rate of water per unit area of floor (L/h-m2).

  • schedule – A ScheduleRuleset or ScheduleFixedInterval for the use of hot water over the course of the year. The type of this schedule should be Fractional and the fractional values will get multiplied by the flow_per_area to yield a complete water usage profile.

  • target_temperature – The target temperature of the water out of the tap in Celsius. This the temperature after the hot water has been mixed with cold water from the water mains. The default essentially assumes that the flow_per_area on this object is only for water straight out of the water heater. (Default: 60C).

  • sensible_fraction – A number between 0 and 1 for the fraction of the total hot water load given off as sensible heat in the zone. (Default: 0.2).

  • latent_fraction – A number between 0 and 1 for the fraction of the total hot water load that is latent (as opposed to sensible). (Default: 0.05).

Properties:

  • identifier

  • display_name

  • flow_per_area

  • schedule

  • target_temperature

  • sensible_fraction

  • latent_fraction

  • lost_fraction

  • standard_watts_per_area

  • user_data

ToString()

Overwrite .NET ToString.

static average(identifier, hot_waters, weights=None, timestep_resolution=1)[source]

Get a ServiceHotWater object that’s a weighted average between other objects.

Parameters

  • identifier – Text string for a unique ID for the new averaged ServiceHotWater. Must be < 100 characters and not contain any EnergyPlus special characters. This will be used to identify the object across a model and in the exported IDF.

  • hot_waters – A list of ServiceHotWater objects that will be averaged together to make a new ServiceHotWater.

  • weights – An optional list of fractional numbers with the same length as the input hot_waters. These will be used to weight each of the ServiceHotWater objects in the resulting average. Note that these weights can sum to less than 1 in which case the average flow_per_area will assume 0 for the unaccounted fraction of the weights. If None, the objects will be weighted equally. (Default: None).

  • timestep_resolution – An optional integer for the timestep resolution at which the schedules will be averaged. Any schedule details smaller than this timestep will be lost in the averaging process. (Default: 1).

diversify(count, flow_stdev=20, schedule_offset=1, timestep=1, schedule_indices=None)[source]

Get an array of diversified ServiceHotWater derived from this “average” one.

Approximately 2/3 of the schedules in the output objects will be offset from the mean by the input schedule_offset (1/3 ahead and another 1/3 behind).

Parameters

  • count – An positive integer for the number of diversified objects to generate from this mean object.

  • flow_stdev – A number between 0 and 100 for the percent of the flow_per_area representing one standard deviation of diversification from the mean. (Default 20 percent).

  • schedule_offset – A positive integer for the number of timesteps at which the lighting schedule of the resulting objects will be shifted - roughly 1/3 of the objects ahead and another 1/3 behind. (Default: 1).

  • timestep – An integer for the number of timesteps per hour at which the shifting is occurring. This must be a value between 1 and 60, which is evenly divisible by 60. 1 indicates that each step is an hour while 60 indicates that each step is a minute. (Default: 1).

  • schedule_indices – An optional list of integers from 0 to 2 with a length equal to the input count, which will be used to set whether a given schedule is behind (0), ahead (2), or the same (1). This can be used to coordinate schedules across diversified programs. If None a random list of integers will be genrated. (Default: None).

duplicate()

Get a copy of this object.

classmethod from_dict(data)[source]

Create a ServiceHotWater object from a dictionary.

Note that the dictionary must be a non-abridged version for this classmethod to work.

Parameters

data – A ServiceHotWater dictionary in following the format below.

{
"type": 'ServiceHotWater',
"identifier": 'Residential_SHW_015',
"display_name": 'Residential Hot Water',
"flow_per_area": 0.15, # how water L/h per square meter of floor area
"schedule": {}, # ScheduleRuleset/ScheduleFixedInterval dictionary
"target_temperature": 60, # target temperature in C
"sensible_fraction": 0.2, # fraction of heat that is sensible
"latent_fraction": 0.05 # fraction of heat that is latent
}
classmethod from_dict_abridged(data, schedule_dict)[source]

Create a ServiceHotWater object from an abridged dictionary.

Parameters

  • data – A ServiceHotWaterAbridged dictionary in following the format below.

  • schedule_dict – A dictionary with schedule identifiers as keys and honeybee schedule objects as values (either ScheduleRuleset or ScheduleFixedInterval). These will be used to assign the schedules to the ServiceHotWater object.

{
"type": 'ServiceHotWaterAbridged',
"identifier": 'Residential_SHW_015',
"display_name": 'Residential Hot Water',
"flow_per_area": 0.15, # how water L/h per square meter of floor area
"schedule": 'Residential DHW Usage', # schedule identifier
"target_temperature": 60, # target temperature in C
"sensible_fraction": 0.2, # fraction of heat that is sensible
"latent_fraction": 0.05 # fraction of heat that is latent
}
classmethod from_idf(idf_string, floor_area, schedule_dict)[source]

Create a ServiceHotWater object from an IDF WaterUse:Equipment string.

Parameters

  • idf_string – A text string of an EnergyPlus WaterUse:Equipment definition.

  • floor_area – A number for the floor area of the room to which the WaterUse:Equipment definition is assigned.

  • schedule_dict – A dictionary with schedule identifiers as keys and honeybee schedule objects as values (either ScheduleRuleset or ScheduleFixedInterval). These will be used to assign the schedules to the ServiceHotWater object.

Returns

A tuple with two elements

  • shw: A ServiceHotWater object loaded from the idf_string.

  • zone_identifier: The identifier of the zone to which the ServiceHotWater object should be assigned. Will be None if no zone is found.

  • total_flow: Number for the absolute flow rate of the ServiceHotWater object in L/h.

classmethod from_watts_per_area(identifier, watts_per_area, schedule, target_temperature=60, sensible_fraction=0.2, latent_fraction=0.05, water_mains_temperature=10)[source]

Create a ServiceHotWater object from hot water power density (W/m2).

Parameters

  • identifier – Text string for a unique ServiceHotWater ID. Must be < 100 characters and not contain any EnergyPlus special characters. This will be used to identify the object across a model and in the exported IDF.

  • watts_per_area – The desired hot water power density (W/m2).

  • schedule – A ScheduleRuleset or ScheduleFixedInterval for the use of hot water over the course of the year. The type of this schedule should be Fractional and the fractional values will get multiplied by the watts_per_area to yield a complete hot water profile.

  • target_temperature – The target temperature of the water out of the tap in Celsius. This the temperature after the hot water has been mixed with cold water from the water mains. The default essentially assumes that the flow_per_area on this object is only for water straight out of the water heater. (Default: 60C).

  • sensible_fraction – A number between 0 and 1 for the fraction of the total hot water load given off as sensible heat in the zone. (Default: 0.2).

  • latent_fraction – A number between 0 and 1 for the fraction of the total hot water load that is latent (as opposed to sensible). (Default: 0.05).

  • water_mains_temperature – The average annual temperature of the water mains that supply the water heater in Celsius. This should be close to the average annual temperature. (Default: 10C).

lock()
set_watts_per_area(watts_per_area, water_mains_temperature=10)[source]

Set the volume flow rate per floor area using the hot water power density.

Parameters

  • watts_per_area – The desired hot water power density (W/m2).

  • water_mains_temperature – The average annual temperature of the water mains that supply the water heater in Celsius. This should be close to the average annual temperature. (Default: 10C).

to_dict(abridged=False)[source]

ServiceHotWater dictionary representation.

Parameters

abridged – Boolean to note whether the full dictionary describing the object should be returned (False) or just an abridged version (True), which only specifies the identifiers of schedules. (Default: False).

to_idf(room)[source]

IDF string representation of ServiceHotWater object.

Note that this method only outputs a string for the WaterUse:Equipment object and a Schedule:Constant for the target temperature. Thus, to write everything needed to describe the object into an IDF, this object’s schedule must also be written.

Parameters

room – The honeybee Room to which this ServiceHotWater object is being applied. This is needed for both to convert the flow_per_area to an absolute flow and to assign the hot water object to the Room (such that sensible/latent heat gains are transferred to the Room).

Returns

A tuple with two values.

  • water_use: A WaterUse:Equipment string for the ServiceHotWater.

  • schedules: A list of Schedule:Constant strings for the schedules needed to describe the target temperatures as well as the sensible and latent fractions.

unlock()
WATER_HEAT_CAPACITY = 4179600
property display_name

Get or set a string for the object name without any character restrictions.

If not set, this will be equal to the identifier.

property flow_per_area

Get or set the hot water volume flow rate per unit area of floor (L/h-m2).

property identifier

Get or set the text string for object identifier.

property latent_fraction

Get or set the fraction of hot water heat that is latent.

property lost_fraction

Get the fraction of hot water heat that is lost down the drain.

property properties

Get properties for extensions.

property schedule

Get or set a ScheduleRuleset or ScheduleFixedInterval for hot water usage.

property sensible_fraction

Get or set the fraction of hot water heat given off as zone sensible heat.

property standard_watts_per_area

Get the hot water power density (W/m2) assuming a standard mains temperature.

Standard water mains temperature is 10C, which is the default water mains temperature in EnergyPlus when none is specified.

property target_temperature

Get or set the temperature out of the tap (C).

property user_data

Get or set an optional dictionary for additional meta data for this object.

This will be None until it has been set. All keys and values of this dictionary should be of a standard Python type to ensure correct serialization of the object to/from JSON (eg. str, float, int, list, dict)