How Are Deli Exhaust Systems Designed for Grocery Prepared Foods?

Every cooking appliance gets a hood matched to its hazard and listed for the application: canopy hoods over fryer and rotisserie batteries, with overhang sized to capture the plume even when equipment doors open. The engineer lays out hoods to avoid cross-drafts from HVAC diffusers or the customer entrance — a draft across a hood spills grease-laden air into the kitchen instead of up the duct. Grease duct is engineered like a chimney that happens to carry flammable residue: continuously welded liquid-tight seams, access panels at every change of direction for cleaning, slope toward a grease collection point, and rated clearances or shaft enclosures through the building. Exhaust fans sit at the duct termination pulling the system negative, with hinges and access for the cleaning crews that keep the duct safe over its life.

Automatic fire suppression is non-negotiable over commercial cooking. Wet-chemical systems with nozzles aimed at each appliance, the plenum, and the duct riser discharge on fusible-link or electronic detection, smothering a grease fire in seconds. The engineer coordinates nozzle coverage with the final equipment layout — move a fryer six inches and the suppression design must be re-verified — and ties the system to gas shutoff valves and the building fire alarm panel. Odor is the neighbor and customer problem. Rotisserie and fryer exhaust carries strong odors that can nuisance neighboring tenants or get pulled back into the store's own intakes. The engineer studies discharge locations relative to intakes and property lines, adds carbon or UV odor treatment where needed, and designs discharge velocity and height to disperse the plume. A deli that smells great inside and is invisible outside is the target.

A complete deli exhaust package captures effluent and protects the building: • Type I hoods sized for plume capture over every fryer, rotisserie, and gas appliance • Grease-rated duct with welded seams, cleanouts, slope, and code clearances • Listed wet-chemical fire suppression with gas shutoff and fire alarm interlock • Dedicated tempered makeup air balanced to total deli exhaust volume • Hood placement coordinated to avoid HVAC cross-drafts and entrance airflow • Odor treatment and discharge design relative to intakes and property lines • Exhaust interlocked with cooking schedules and verified at commissioning