Hello All,

I am looking to get some clarification or consensus regarding modeling the baseline HVAC systems for EAc1.3.

My specific scenario is that we have a core and shell building, under construction, that recently completed the LEED design portion of CS, and is showing considerable savings over ASHRAE Baseline.

Next we are starting the certification process for the tenant fitout under CI.

In the previous comments, it has been suggested that since this credit only counts any savings from the newly designed HVAC systems, if any, for the fitout, the 'existing' (CS) building envelope and systems that are untouched should be modeled identically in both cases.

If this statement holds true, then for my specific building scenario, since we are not modifying the central plant or central air distribution - these were sized and designed for the CS building - what strategies, if anything, can i employ in the CI design building or baseline building to show savings?

Is this design scenario appropriate to try and show savings? The tenant fitout is approximately 1/3 of the total square footage of the building, and the rest of the building is not within the project scope and has not been leased as of now.

It is a DX VAV water cooled building, and the basic system differences between the CS design and the fitout design is that for the fitout, the VAV zones and interior loading have been defined, where as in the CS design the VAV zones and loading were assumed.

Is that enough of an HVAC systems change that I go through the process to select the appropriate baseline HVAC system via ASHRAE chapter 11 HVAC systems map (Water cooled, electric heat, non-residential) and model the baseline per chapter 11?

Thanks in advance.