Depending on where your commercial kitchen is located, a makeup air system isn't always required. However, it's always a good idea to install one, no matter what. Exhaust fans and your furnace and ductwork do all they can to keep the air in your kitchen clean and fresh. Unfortunately, because of the large amounts of smoke, grease, and food particles that get released into the air, it's nearly impossible for them to keep up. A makeup air system is a great way to boost the quality of air in your kitchen.