Ok - so I guess I'm hoping someone can confirm this - I will be looking to model for LEED a commercial kitchen hood and makeup air system. not sure the details yet - probably a gas fired makeup air unit - but my question is this - do I have to treat this as a separate system under appendix G? I know I can give it a DOA unit for the proposed but I'm not sure how to handle the Baseline. Should it be the same? if not - what system type should it be. seems to me that this space would fall into both exception b and c under section G3.1.1 which would mean I would need a separate system for this space? Has anyone else out there done this? Thanks.
I agree - one of those exceptions should allow you to split out that system. I believe for this you could go back to table G3.1.1.A and B and pick the baseline system as if the kitchen unit was in a stand-alone building. From what you have said I'm guessing its System Type 3.
You might want to check the Ventilation and/or Energy Recovery requirements as well. Typically the baseline ventilation needs to match the proposed, and you might have to account for energy recovery in the baseline case if you ventilation percentage is large enough for this unit.
I actually just modeled a similar building that had a kitchen hood. I did model it as a separate system. With that said be sure to model it with both heating and cooling. The MAU used was a gas fired one, so I originally created a "Ventilation and Heating" system, which only has a heating coil. However, when I submitted it, I was told that it must be modeled with heating and cooling, even if the actual MAU only has heating. So, I just modeled my MAU system as a "Single Zone" and they didn't have a problem. Hope this helps.
DISCLAIMER: There may be a better system than single zone to use for modeling a MAU.