Do I need a hood for a commercial kitchen?
If you run any equipment that produces grease-laden vapor or smoke — fryers, griddles, charbroilers, open-burner ranges, woks — you need a Type I exhaust hood with grease filters and fire suppression. Equipment that produces heat or steam but no grease (high-temp dish machines, steamers, some ovens) needs a Type II hood. A beverage or cold-prep operation with only low-heat countertop equipment may need no hood at all. Your local authority (AHJ) makes the final call.
What's the difference between a Type I and Type II hood?
A Type I hood is for grease and smoke: it has grease filters, a fire-suppression system, and a grease-tight duct to the roof. A Type II hood is for heat, steam, and moisture without grease — for example over a dish machine or a bakery oven — and is simpler because it doesn't handle grease or need suppression. If any appliance produces grease, you're in Type I territory for that appliance.
Can I open a restaurant without a hood?
Sometimes — if you cook only with listed ventless (UL 710B) equipment or avoid grease-producing cooking entirely (think a coffee shop, a salad concept, or a menu built on ventless combi ovens and induction). Ventless cooking equipment has built-in filtration and fire suppression and is designed to operate without a hood, but it must be listed for that use, sited per its listing, and accepted by your local authority. Always confirm before you sign a lease.
Do food trucks need a hood?
Almost always, yes — if the truck has a fryer, griddle, charbroiler, or range, it needs a Type I hood and fire-suppression system just like a fixed kitchen, sized to the cooking line. Mobile-unit rules and the exact hood requirement vary by jurisdiction, so check your local mobile-vending and fire-code requirements.
Does this tool meet code?
No — it's a planning guide based on standard mechanical-code principles (IMC 507). Hood type, size, clearances, make-up air, and duct routing are set by the International Mechanical Code, the appliance listings, and your local authority. A licensed mechanical engineer sizes and stamps the real system.