HOWEVER ....
A careful reading of NFPA 96 is quite clear on two commonly misrepresented points.
First, "make up air" is specifically described as air supplied specifically to the hood, from within the hood assembly. NFPA 96 does NOT call for shutting down the general air supply to the kitchen, or shutting down the general air conditioning. Doing so is not forbidden - but it's not required.
Second, NFPA 96 is quite blunt that the exhaust fan need not operate if the cooking units and hood are "off." The fan need operate only when the equipment is operating.
hem and haw and engineer all you want, but your 'design ideas' may not be what the code actually calls for.
