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Baseline Modeling

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  rev. 2015-04-17        

 

Automatic Baseline Modeling is a batch process for creating Default Baseline Models for Meter Reading Components.  This feature provides sophisticated industry-standard modeling, in adherence with ASHRAE Guideline 14-2002 and IPMVP protocols.  ManagingEnergy hides the underlying complexity beneath a simple user interface.

 

                                                                 Advanced users who want detailed inspection and control of baseline models can make use of Individual Baseline Modeling in the Conservation & Renewal module.

 

First pick the facilities you wish to work with.  Select one facility in the Facility Tree, a Group in the Portfolio Tree, or the Portfolio Node to select the entire portfolio.  Click the Auto Baseline Modeling button.

Now pick the baseline period and the utilities to model.  The default is All utilities.

You can choose whether to overwrite existing models if they exist. Note that if you do not check the Replace Existing Models box, only meters which do not have an existing model will be overwritten. If you have recently updated information within the Baseline Reference Period for a meter with a model, these changes will not be reflected in their models.

Selection or disabling of heating or cooling sensitivity is also available at this stage.

 

                                    Baseline models should span a full operating cycle. They should represent all operating conditions of a normal operating cycle, and include only time periods for which all fixed and variable energy-governing facts are known. The model also should coincide with the period immediately before commitment to undertake the retrofit in order to give a more complete snapshot of the facility before the retrofit.

 

Press Next to run the process.  A progress bar will appear during processing, and a Completed note will appear when it is done.  Click Finish to return to the main screen.

It may take up to five minutes for the updated baseline data to become visible in Performance dashboard, reports, and exports as the system finishes the computations.

 

Baseline Modeling follows a statistical process to deal with invoice anomalies and to determine whether and how utility consumption is influenced by weather.  The modeling engine tests both heating and cooling sensitivity, looking for a T-statistic greater than 3.0 and then selecting the heating balance point and cooling balance point to provide the maximum R-Value (regression fit).  The conditions in the table below are handled as shown.

Condition

Description / Response

Estimated meter reading

Estimates can be far from reality, so they can reduce the reliability of the model if they are included as-is.  Fortunately, estimated readings can be used to calculate the consumption between actual readings.  For auto baseline modeling, ManagingEnergy adds estimated readings to the next actual reading to create a single useful reading.  Where there are two or more adjacent estimated reading, they are all consolidated with the first available actual reading to form a single reading for modeling purposes.  The reading period for the single reading incorporates the included estimate periods.

For estimated demand meter reading components, the value for the actual reading is used.

 

 

Statistical outlier within the baseline period.

Statistical outliers are included in the model.

Less than a full calendar year in baseline period.

Permitted.  This will often result in an unbalanced representation according to ASHRAE Guideline 14-2002 (e.g. over-representation of colder months) but generally will not invalidate the model.

Minimum readings required.

At a minimum there should be enough readings to represent a full cycle of operation. For most applications this would require enough readings to span a full year. The modeling process itself requires at least one more reading than the number of  independent variables included in the baseline model. For example with three independent variables (HDD, CDD, and Occupancy) you would need a minimum of 4 readings in the baseline period.

 

 

 

Model Status Flag

To the right of each meter in the Facility Tree is a status flag, indicating the condition of the consumption default baseline model.  If the flag is faded grey, no default model exists for this meter. If it is yellow, the model exists with an R2 less than 0.7. If it is green, the model exists with an R2 greater than 0.7.

 

Related Topics

Individual Baseline Modeling

 



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