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Calibration to actual energy use??

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Mon, 12/13/2010 - 13:57

Re: Calibration to actual energy use?? Without knowing exactly where you are looking in the reference guide, I believe the intent of the word "calibrate" is to coordinate the design of your project's metering system / Measurement and Verification Plan with your energy simulation model. In other words, if your energy simulation measures plug loads and lighting loads separately, these values should also be tracked separately in the actual building's metering design - so the design intent can be verified. As regards the "as-built" language, can you provide a page reference?

Mon, 12/13/2010 - 18:36

"Calibration" means adjusting the independent variables in the energy model to suit actual conditions. This includes variables like weather, hours of occupany, occupancy densities, and equipment/system operational schedules. After these adjustments are made the model is re-run, and the calibrated results are compared to the actual energy use of the building over the one-year M&V period. This comparison occurs at the system as well as whole-building level. Significant deviations between the actual and projected energy use are then investigated and reconciled/resolved. While properly conducted energy modeling can be surprisingly accurate, it is not perfect and some deviations can be expected. My guidelines for what constitutes acceptable correlation are as follows: +/- 10% for total annual energy use +/- 10% for total annual energy use for each energy source +/- 15% for total monthly energy use +/- 15% for monthly energy use for each energy source for any month with use higher than 30% of the peak month +/- 15% for end-uses on an annual basis +/- 15% for end-uses on a monthly basis for any month with use higher than 30% of the peak month I hope this helps.....

Tue, 12/14/2010 - 03:18

Yes, thank you very much, it is clear now. So if I understand correctly, if you have just one meter for the whole building and you have a properly planned M&V plan, and you compare the calibrated energy model with the actual annual consumption you are eligible to earn this credit under Option D, right?

Tue, 12/14/2010 - 14:10

Uh, no. While it could be argued that whole-building meters are sufficient for very small buildings, any building of significant size will require submetering or deductive indirect metering of at least the main energy end-uses e.g. lighting, plug, major mechanical equipment, etc. The extent of the submetering is left to the discretion of the practioner, but it must be sufficient to demonstrate, through the M&V process, that the building and its systems are performing as projected.

Tue, 06/26/2012 - 23:01

According to the M&V Plan Sample, (3.1 Electricity Baseline Simulation) The energy model files shoud be supplied to the owner, and then be available for verification and calibration. After 1 year of post-construction occupancy, who is resposible of this calibration process?. Should the company responsible for the energy modelling re-run the program?, Or would be enough to compare the results of the energy measurement with the energy model?

Wed, 06/27/2012 - 00:42

The responsible party can vary. Typically the original energy modeler calibrates the model. It is not nearly enough to compare actual and modeled data.

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