I am currently working on a fire station building in NC and I'm using HAP 4.8 to model this building vs. the baseline. For our proposed building occupied areas, we are using a VRF system with a dedicated outside air unit. For the Bay area (garage) we are using a radiant heated slab to heat during the winter and opening the bay doors to cool in the summer. The bay area also has a vehicle exhaust removal/filtration system that recirculates, so no exhaust fans are required for air changes. Per ASHRAE all conditioned spaces shall be simulated as both being cooled and heated even if no heating or cooling system is to be installed. For my climate zone (3) a conditioned (heated) space is defined as one that has a heating output of 10 Btuh/sqft and the Bay area falls under that category. Also per AHSRAE app G., the baseline system I am supposed to model is a Constant Volume Packaged Rooftop HP with electric heat.
My questions are:
How am I supposed to model this in HAP for both the baseline and proposed building?
For the baseline, do I include the exhaust fan energy it would require to maintain the airchanges in the space since we would not use the filtration system? Do I include this as OA in the Packaged HP that would be cooling/heating the space in the baseline model and not include it in the proposed since we have a filtration system? Is there any way exclude the Bay area from the model?