Hi, I am working on a 5 story self storage building in Shoreline WA as the modeler. I am thinking to make the baseline building have cooling per ASHRAE 90.1 2010, but am unsure if that will fly, given the warehouse type occupancy would typically have fossil fuel furnace and ventilation only. Does anyone have any experience with this that they could share?
Thanks
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5868 thumbs up
March 25, 2017 - 1:33 pm
I would model the spaces as heating only using a system 9 or 10 in the Baseline.
Jeremiah Crossett
March 25, 2017 - 2:26 pm
Marcus, Thanks, for your input.
The only problem with system 8 or 9 that I forgot to mention is that we are using thermal mass and phase change materials with nightime mechanical ventilation in order to cool the building, thus would like to claim the cooling savings. Considering this what system type would you think appropriate to model baseline the HVAC?
Thanks again
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5868 thumbs up
March 25, 2017 - 2:57 pm
You don't get to pick and choose the baseline system type. You are required to select it based on Appendix G.
That said if you wish to claim the savings you seek it will require an exceptional calculation which would need to include sufficient justification for your baseline system comparison.
Jeremiah Crossett
March 25, 2017 - 7:22 pm
Thanks Marcus,
I was looking at "Nonresidential and 4 or 5 Floors and <2300 m2 or
5 Floors or Less and 2300 m2 to 14,000 m2 System 5—PackagedVAV with Reheat" due to building size, but I suppose that the Building Type would supersede building System 9—Heating and Ventilation resulting in size and System 9—Heating and Ventilation.
It is also noteworthy that the building is in shoreline Washington and is being filed as a fully conditioned building with building code and I am planning on using Washington state energy code min as the baseline.
Lastly, I have done exceptional calculation models with E+ for PCM's when the primary LEED model was done in TRANE, and for this do not see why this would fall into the exceptional calculation category.
Thanks again for your insight
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5868 thumbs up
March 26, 2017 - 11:35 am
I think you have to use heating only if it applies.
Not sure that the code filing matters much for this situation but it could be a part of your justification for selecting an alternative baseline system.
It is an exceptional calculation whenever you must violate a part of the modeling protocol to show savings. In your case you would need to justify an alternative baseline system and change the schedule relative to ventilation during unoccupied hours, Either one alone requires an exceptional calculation where you must justify the baseline as standard practice for a building of this type in this location.
Exceptional calculations are required for LEED when:
1. A workaround is required in the software.
2. You must violate a part of the modeling protocol to show savings.
3. To claim savings for a process load.