Energy Modeling for GCHP Systems - Manipulating Buildings and Systems

Energy Modeling for GCHP Systems - Manipulating Buildings and Systems

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Hi, my name is Ed Lohrenz with GEOptimize.

This video illustrates how an hourly energy model can be used as a powerful design tool, and how it can be used to manipulate the heating and cooling peak loads and annual energy loads to both improve the energy efficiency, and more importantly, to optimize the performance of a GHX in a GCHP system.

Accurate energy modeling is needed when designing a GCHP system for a couple of reasons:

  • Optimize the design of the GHX

  • Minimize the capital cost of building the GHX

  • Improve the performance of the GHX and GCHP system

  • Ensure the GHX will continue to work efficiently over the long term

  • Estimate energy consumption and cost

  • Develop information package to allow the owner and/or building manager to operate the system appropriately

In addition to GLD, there are several other software packages that are commonly used in the GCHP industry. GLD provides the most flexibility in designing a GHX, and provides the designer a number of features that are not available in the other software packages.

Using a software package in conjunction with energy modeling software allows you as an energy modeler to quickly see the impact of changes to the building or building systems and can help optimize the cost and performance of a system.

Trane Trace generates a number of files for each water source heat pump alternative when the loads are calculated. These can be found in the same folder as the Trace file you are running. These will be number GL1, GL2, etc. for as many water source heat pump alternatives that are being run.

The files are Excel Comma Separated Values files, or .csv files.

When you open a .csv file, you will find 6 columns of information, including:

  • COLUMN A:  The day of the year, with 24 rows (hours) for each day

  • COLUMN B:  The Date and time – 8,760 hours

  • COLUMN C:  Heating delivered in Btu/hr for 8,760 hours

  • COLUMN D:  Cooling delivered in Btu/hr for 8,760 hours

  • COLUMN E:  Heating delivered in kW

  • COLUMN F:  Cooling delivered in kW

The information needed by GLD is either COLUMNS C & D, OR COLUMNS E & F