Energy Modeling Procedure for a Data Center

I do not believe that is the case.

Hi Santiago,
On this webpage on the very far bottom it says that you can use the spreadsheet also for version 2009:
http://www.usgbc.org/resources/minimum-energy-performance-data-center-ca...
So I believe that you can use this excel file too.

You can use the spreadsheet to show savings but you cannot just use the spreadsheet and not perform an energy model for a LEED 2009 project.

Thanks Marcus for the fast response, but does this make sense?
Why should I show savings by the spreadsheet and than run a energy model in addition. Most likely the model and the spreadsheet will not lead to the same result.
Did you had this situation already in one of your v2009 projects or what convinces you on the point that we definitely need a energy model also?
Best and thank you very much

Maybe I responded too quickly. I have been reviewing this credit as a contractor to USGBC/GBCi for over ten years so my statements have been based on that experience.

As far I I know we have not been notified that it would be acceptable to not do an energy model for LEED 2009 projects. But perhaps this situation has not yet come to the fore. After looking this over a bit more closely USGBC might allow the first option (no additional model) since it will likely produce a conservative level of savings. You might want to ask them directly.

The second option listed in the spreadsheet is to use both. The spreadsheet only does the IT equipment savings and does not account for any building related savings so they are not trying to produce the same result. One shows the IT savings the other shows the impact on HVAC and the savings from the other building systems. It is the accumulation of both types of savings that could contribute to the overall savings.

Marcus, does this mean that the results of a typical energy model (i.e EQuest model) and the DC spreadsheet can be used in paralell (in order to prove aminimum of 2% energy cost savings from building systems, as required by v4) or can the output of the DCspreadheet be imported in the EQuest model as process load?

Maybe a little of both.

To include savings from the IT load and the building loads you prepare the typical models with the IT process load identical based on the baseline. You then prepare an exceptional calculation to account for the savings in both the IT load and the savings related to the impact of the reduced IT load on the building systems. To do this you would typically extract the information from the spreadsheet and create a revised proposed model and enter the differences in the exceptional calculation. There should be cooling savings in addition to the IT equipment savings.

OK I dug into this a bit more. I think I now understand what the spreadsheet instructions are saying. I certainly agree that the language is confusing.

In all cases you are required to prepare two energy models. This is required by the credit language and there are no exceptions in 2009 or v4. Option 1 does not excuse you from doing any energy models.

Under Option 1 you do not have to do an additional model via the exceptional calculation method. You can simply claim the savings from the spreadsheet in the proposed model within the form. Under option 2 you do an additional model under the exceptional calculation method to account for the interactive effects related to the reduced IT load.

I don't think you need to provide anything else. If the reviewer has an issue with your inputs they will ask for something additional.