Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
I don't see the contradiction with 90.1-2007 G3.1.2.5 (Note: different versions of the standards have different numbered sections, so it's helpful to specify the standard version when citing a specific section).
In your proposed case, say Zone 1 (served by AHU) receives 50 CFM of outside air, and Zone 2 (served by FCU) receives 0 CFM. In the baseline model, you would model both zones attached to a single AHU, which you model delivering a minimum 50 CFM of outside air. Thus the minimum outside air ventilation rates are the same (50 CFM) in the proposed building and baseline building designs, which meets the language of 90.1-2007 G3.1.2.5.
| | 2 | No.2 Revision |
I don't see the contradiction with 90.1-2007 G3.1.2.5 (Note: different versions of the standards standard have different numbered sections, so it's helpful to specify the standard version when citing a specific section).
In your proposed case, say Zone 1 (served by AHU) receives 50 CFM of outside air, and Zone 2 (served by FCU) receives 0 CFM. In the baseline model, you would model both zones attached to a single AHU, which you model delivering a minimum 50 CFM of outside air. Thus the minimum outside air ventilation rates are the same (50 CFM) in the proposed building and baseline building designs, which meets the language of 90.1-2007 G3.1.2.5.
| | 3 | No.3 Revision |
I don't see the contradiction with 90.1-2007 G3.1.2.5 (Note: different versions of the standard have different numbered sections, so it's helpful to specify the standard version when citing a specific section).
In your proposed case, say Zone 1 (served by AHU) receives 50 CFM of outside air, and Zone 2 (served by FCU) receives 0 CFM. In the baseline model, you would model both zones attached to a single AHU, which you model delivering a minimum 50 CFM of outside air. Thus the minimum outside air ventilation rates are the same (50 CFM) in the proposed building and baseline building designs, which meets the language of 90.1-2007 G3.1.2.5.
Edit: your FCU zone might fall under the G3.1.1 exceptions, in which case it would not need to be attached to the AHU in your baseline, and the System 4 serving it would be modeled with 0 CFM of outside air.
