Restaurant Conversion: Hood Exhaust, Make-Up Air, and Kitchen Finishes

The first conflict is exhaust and make-up air balance. A 2,400 cfm kitchen hood cannot operate with only 1,200 cfm of make-up air; the space will depressurize, doors will be hard to open, and the hood will not capture smoke and grease properly. A dedicated make-up air unit sized at roughly 80 to 90 percent of exhaust, with the remainder drawn from the dining room, is the typical strategy, but the designer must verify the path and the transfer grilles. The second conflict is the rooftop structure and electrical load: the existing 10-ton unit may not have capacity for the added outdoor-air load, and the 200A service may not carry the new kitchen equipment. The third is gas: 400 MBH may be insufficient for the cooking line and water heater. The fourth is the grease duct and the 2-hour hotel wall. The grease duct must be enclosed or listed for the application, with clearance to combustibles, and it cannot penetrate the rated wall without a listed assembly. The fifth is the grease trap, which must be sized for the fixtures and located for access. Ordering the hood before resolving make-up air and structural support is risky; the hood is only one part of an interdependent system.

In the kitchen, the floor should be quarry tile or another slip-resistant, grease-resistant surface with a coved base and epoxy grout. The reasoning is cleanability, chemical resistance, and a seamless transition at the wall so grease and water cannot collect. The walls should be smooth, washable, and light-colored, such as glazed tile or stainless panels at the cooking line, because the hood and splash zone receive frequent cleaning. The kitchen ceiling should be cleanable and moisture-resistant; exposed structure may be acceptable only if it is smooth and accessible for cleaning, but acoustic tile is a poor choice in a grease-laden area. In the dining room, polished concrete can work, but it needs a slip-resistant sealer and a maintenance plan; the owner should understand that polished concrete stains and requires periodic re-polishing. The exposed ceiling in the dining area supports the design intent, but it makes acoustics harder. I would specify a sound-absorbing treatment on the upper walls or a suspended acoustic cloud, and separate the open kitchen with a partial screen or hood enclosure. The 2-hour hotel wall must remain intact; any finish or penetration on that wall needs a listed assembly and firestopping.

Prioritize odor at the source first: a properly sized hood, capture velocity, and make-up air that prevents the kitchen from going negative relative to the hotel. Then check the exhaust discharge location; it should be away from hotel intakes, operable windows, and pedestrian areas, and it should have the required clearance. Grease filters and a scheduled cleaning plan matter as much as equipment selection. For noise, separate the kitchen from the dining room with a partial wall or screen, isolate the hood fan and make-up air unit with vibration isolators and flexible connectors, and locate rooftop equipment away from the hotel wall. Inside the dining room, address reverberation with acoustic absorption because the exposed ceiling will otherwise amplify 120 patrons. I would tell the owner that the 14-week schedule is at risk if the make-up air unit, grease duct, and structural support are ordered before coordination. The hood may arrive on time, but the project can stall on the electrical service upgrade, the gas load, or the grease trap. A coordination deadline for those items should be set before release of the equipment purchase order.