Ventless Hood Systems Guide: Wells, Giles, and Codes

Chicago inspectors are tough. I once failed an inspection because a hand-sink was 3 inches too far to the left. So when a client asks me, “Chef, can I just use a ventless hood and skip the roof work?” I get nervous.

The answer is Yes, but with a massive asterisk.

A Ventless Hood (or Recirculating Hood) is a miracle of modern engineering. It allows you to fry chicken in a basement, grill burgers in a skyscraper, or bake pizza in a kiosk where you physically cannot punch a hole in the roof.

According to UL Standards, specifically UL 710B, these systems must automatically shut down cooking equipment if the fire suppression system is compromised or filters are clogged.

However, it is also a maintenance nightmare, a regulatory minefield, and a piece of equipment that will literally shut your kitchen down if you forget to wash a filter.

This guide is the result of 15 years of fighting with Fire Marshals. I’m going to tell you whether the $15,000 price tag is worth it.

How It Works: The “Magic Box”

A traditional “Type 1” hood sucks grease and smoke up a duct and spits it out onto your roof. A Ventless Hood eats that smoke and spits clean air back into your kitchen.

The 4-Stage Filtration Process

1. Stage 1: The Baffle Filter: Just like a normal hood. This stainless steel grate catches the big heavy grease particles.
2. Stage 2: Pre-Filter: A mesh screen that catches lint and smaller dust.
3. Stage 3: HEPA / Espresso Filter: This is the heavy lifter. It removes 99.97% of smoke particles (down to 0.3 microns). This is why you don’t see smoke in the room.
4. Stage 4: Charcoal Filter: This absorbs the odors.

The “Interlock” (The Brain)

Here is the catch: The Hood Controls the Equipment. You plug your fryer into the hood, not the wall. If the hood senses that a filter is clogged, missing, or improperly seated, it cuts power to the fryer. Mid-service. No manual override.

The Big Rules: What You Can & Cannot Do

Rule #1: ELECTRIC ONLY

This is non-negotiable.

• You CAN use: Electric fryers, electric griddles, electric ovens, induction burners.
• You CANNOT use: Gas equipment.
• Why: Burning natural gas produces Carbon Monoxide (CO). Ventless hoods filter grease, not CO. If you put a gas range under a ventless hood, you will poison your staff and customers within an hour.

Rule #2: UL 710B Certification

Do not buy a “filtered fan” from Amazon. It must be UL 710B Certified (Recirculating Systems). If it doesn’t have that sticker, the Fire Department will laugh you out of the building.

Rule #3: EPA 202 Compliance.

The system must prove that it releases less than 5mg of grease per cubic meter of air. This is the “EPA 202” test. Both Giles and Wells pass this ease.

The Contenders: Wells vs. Giles

1. The Giles System (The Integrated King)

Giles (based in Alabama) basically invented this category for frying chicken.

• The Design: Their most popular unit, the Giles Ventless Fryer, is an all-in-one. The hood is bolted onto the fryer body.
• Pros: Compact. Roll it in, plug it in, fry chicken.
• Cons: You are stuck with their fryer. If you don’t like their pressure fryer, too bad.

2. The Wells System (The Universal Hero)

Wells (a Middleby company) makes the WVU (Wells Ventless Universal) hoods.

• The Design: It’s a stand-alone canopy on legs. You can roll any electric equipment underneath it.
• Pros: Flexibility. You can put a Toastmaster griddle, a Vulcan fryer, and a TurboChef oven under one Wells hood.
• Cons: It is massive and heavy.

The “Chef’s ROI” Calculator

Is it cheaper than a real hood? Let’s run the math.

Scenario: A concession stand in a mall.

Verdict: In difficult buildings (Malls, High-rises, Historic Districts), Ventless is cheaper. In a single-story strip mall where you can just punch a hole in the roof? Traditional is cheaper.

The “Smell Factor” (The Dirty Secret)

Sales reps will tell you these hoods are “Odorless.” They are lying.

These hoods remove particulate smoke. They remove grease. But if you are deep frying cod and catfish for 8 hours a day, your restaurant will smell like fish. The Charcoal filters help, but they saturate quickly.

Chef’s Tip: If you use ventless, you still need a good HVAC system to cycle the air in the dining room, or your customers will leave smelling like French Fries.

Maintenance Guide: The “Filter Tax”

If you buy a ventless hood, you are signing up for a subscription service. You just don’t know it yet.

Daily

• Wash the Baffles: Dishwasher.
• Wipe the Sensors: There are little vacuum sensors inside. If they get greasy, the hood thinks the filter is clogged and turns off your fryer.

Monthly / Quarterly

• HEPA Filter: $100 - $150 each.
• Charcoal Filter: $50 - $80 each.
• Annual Cost: Expect to spend $800 - $1,200 per year on filters alone.

The “Friday Night Nightmare”: It is 7:00 PM. The kitchen is slammed. Suddenly, the hood beeps. The red “CLOGGED” light flashes. Click. Your fryers turn off. You cannot turn them back on until you replace the filter. Do you have a spare $150 filter in the office? If the answer is “No,” your kitchen is closed for the night. Always keep a spare set of filters.

Fire Marshal “Grey Areas”

Just because it is UL Certified doesn’t mean your local inspector has to allow it. The “AHJ” (Authority Having Jurisdiction) is God.

I have seen inspectors in NYC dictate that ventless hoods must also have a duct “just in case.” (Which defeats the whole purpose of NFPA 96 Chapter 13 approvals). I have seen inspectors require a “makeup air” fan even for ventless hoods.

Chef’s Rule: Before you spend $15,000, take the Spec Sheet (Cut Sheet) to your local Fire Department. Ask for the “Plan Review” officer. Show it to them. Get them to sign a piece of paper saying “This is OK.”

Troubleshooting Matrix

Frequently Asked Questions (FAQ)

Q: Do ventless hoods remove 100% of the smell? A: No. They remove about 80-90%. Strong odors like fish or garlic will still linger. You need secondary HVAC.

Q: Can I use a gas fryer under a ventless hood? A: NEVER. Ventless hoods do not remove Carbon Monoxide. Using gas equipment without an external vent is illegal and dangerous.

Q: How loud are they? A: Loud (70-75dB). It sounds like a large vacuum cleaner running constantly in the kitchen.

Top 3 Commercial Ventless Hood Recommendations

If you can’t punch a hole in the roof, buy one of these.

1. Best Overall (The Universal Choice): Wells WVU Series

• Best For: Food courts, Historic buildings, Pop-ups.
• Why It Wins: It is a standalone canopy. You can roll any electric equipment underneath it (Fryer, Griddle, Range). If your menu changes, you just swap the equipment, not the hood.
• Flexibility: It has the best fire suppression integration in the industry.

2. Best Integrated (The Fried Chicken King): Giles

• Best For: Supermarkets, Delis, Convenience Stores.
• Why It Wins: Giles often builds the hood into the fryer (like the GEF Series). It is one solid unit.
• Performance: It handles the heavy grease load of pressure-fried chicken better than anyone else.

3. Best Self-Cleaning (The Tech Pick): CaptiveAire

• Best For: High volume kitchens that hate cleaning.
• Why It Wins: Some models feature self-cleaning technology that washes the grease extractors automatically.
• Note: CaptiveAire is primarily a ducted hood company, so their support network is massive.

Final Summary

If you need flexibility (changing menu), buy Wells. If you are just frying chicken 24/7, buy Giles.

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