I am working on a project to build-out the 2nd floor of a 2-story law school building, approximately 9,000 square feet for each floor. The building's HVAC systems are served by a central heating and cooling plant that also serves many other buildings.
I was reading through USGBC's Treatment of District or Campus Thermal Energy in LEED V2 and LEED 2009 - Design and Construction and the only mention to LEED CI is to refer to Appendix A.
Appendix A states for LEED-CI that "District Energy Systems have no effect on any EA section prerequisites or credits. Any effects of the District Energy Systems shall be picked up by SS Credit 1, Site Selection, under one of the following paths..."
So my question is, what do I model for the baseline and proposed cases in my energy model? I am modeling the entire building because there is a separate ventilation air preconditioning unit serving all building AHUs, which means I am affecting the performance of a system that serves the entire building. I fall under System 3 for my baseline case according to Appendix G for the whole building. What does this Appendix A mean? Do I model both cases as purchased chilled water and purchased steam?
I was prepared to obtain the metered kW/ton values for the entire plant for my virtual DES in the energy model until I came across this Appendix A (I've done many NC models, but this is my first CI model).
Paul Conrad
Energy EngineerCLEAResult Consulting
346 thumbs up
December 9, 2010 - 11:38 am
Jason,
Your safest bet is to model it exactly as though you would an NC District Thermal Energy System, then isolate the portion of the building that is being built out and compare that. I realize that this is a lot of work, but it's the method that is most likely to get approved by a reviewer.
I would recommend against trying to model it in some other fashion, unless you submit a CIR to get clarification on what the EA TAG would like to do in this situation.
Paul
Evelyn Dicks, EI, CxA
Mechanical EngineerMoses and Associates
83 thumbs up
December 9, 2010 - 1:26 pm
Thanks Paul, I was going to do exactly what you stated in the first part of your response, until I came across that Appendix A that solely address LEED CI 2009.
I just don't know what USGBC's intent was when developing this Appendix A. Something has to be modeled for my cooling and heating sources along with a utility rate, but this is unclear according to their Treatment of DES document.