Energy Conservation Measure

Biased Economizer Sensor: Mixed Temperature

Name 
biased_economizer_sensor_mixed_t
Display Name 
Biased Economizer Sensor: Mixed Temperature
UID
3a9ab8b0-6fe8-4395-9f3e-57726ae4edaa

Version ID
12cf68e9-9a14-43ca-849b-335aee09728f
Class Name 
BiasedEconomizerSensorMixedT
Version Modified 
20180828T220925Z
Schema Version 
3.0
Rating 
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Attributes 
Measure TypeEnergyPlusMeasure
Intended Software ToolOpenStudio Application
Intended Software ToolParametric Analysis Tool
Intended Software ToolAnalysis Spreadsheet

Details

DescriptionWhen sensors drift and are not regularly calibrated, it causes a bias. Sensor readings often drift from their calibration with age, causing equipment control algorithms to produce outputs that deviate from their intended function. This fault is categorized as a fault that occur in the economizer system (sensor) during the operation stage. This fault measure is based on a physical model where certain parameter(s) is changed in EnergyPlus to mimic the faulted operation; thus simulates the biased economizer sensor (mixed air temperature) by modifying the SetpointManager object assigned to the economizer. The fault intensity (F) is defined as the biased temperature level (K). A positive number means that the sensor is reading a temperature higher than the true temperature. This measure was authored by Herrick Laboratory researchers at Purdue University in collaboration with staff from the National Renewable Energy Laboratory. For assistance using this measure please post to https://unmethours.com/questions/
Modeler DescriptionTwo user inputs are required and, based on these user inputs, the setpoint temperature at the mixed air temperature node will be replaced by the following equation, Tma_setpoint,F, = Tma_setpoint – F, where Tma_setpoint,F is the mixed air temperature setpoint affected by the bias, Tma_setpoint is the actual mixed air temperature setpoint, and F is the fault intensity. To use this Measure, choose the Controller:OutdoorAir object to be faulted. Set the level of temperature sensor bias that you want at the mixed air duct for the economizer during the simulation period. Positive value of F means sensor is reading higher value than the actual temperature. The algorithm checks if a real sensor exists in the mixed air chamber, and set up the bias at the sensor appropriately if it exists. For instance, SetpointManager:MixedAir does not model a real temperature sensor in the mixed air chamber, and will not be affected by this model.
Files 
measure.rb
OpenStudio 2.4.0
Min Compatible Version: 2.4.0
Max Compatible Version: 2.4.1
LICENSE.txt
Content visibility 
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Measure Arguments

NameDisplay NameShort NameDescriptionUnitsTypeRequiredModel DependentDefault ValueChoicesMin ValueMax Value
econ_choiceChoice of economizers.---Choicetruefalse----
mix_temp_biasEnter the bias level of the mixed air temperature sensor. A positive number means that the sensor is reading a temperature higher than the true temperature. (K)---Doublefalsefalse2---

Measure Outputs