Required over commercial grease-producing cooking

Commercial Kitchen Hood Wet-Chemical System (UL 300)

Ansul · Amerex · Pyro-Chem · Kidde Fire Systems Canada & United States $$$ · About USD $3,500–$25,000+ depending on hood size

A pre-engineered system inside the exhaust hood sprays potassium-based wet chemical onto the appliances, plenum and duct when fire is detected, and shuts off the gas or power to the cooking line. It is required over most grease-producing commercial cooking.

Why we like it

Agent saponifies hot grease into a foam blanket and cools it
Automatically shuts off fuel or power to the cooking line on release
Several makers offer mechanical, pneumatic and electronic release options

Watch out for

Any change to the cooking line requires re-evaluation of nozzle coverage
Agent is corrosive; clean-up and equipment damage follow a discharge
Semiannual inspection required, about USD $200–$500 a visit

Best for

Restaurants, cafeterias and any commercial kitchen cooking with grease under a hood.

Read the full market guide — costs, install effort and alternatives ↓

Market guide

The whole commitment, end to end

What this actually is, what the market looks like, what it really costs, and how much of your time it wants — before you spend anything.

Buying it Moderate

Installing it Major project

Living with it Moderate

Up front

Small cookline about USD $3,500–$7,000 (≈ CAD $4,800–$9,700); mid-size USD $7,000–$12,000 (≈ CAD $9,700–$16,600); large or multi-hood USD $12,000–$25,000+ (≈ CAD $16,600–$34,500+). Example: an Ansul R-102 on a 10 ft hood at about USD $10,400 for hardware and install, before permit and acceptance test.

Lead time

Days to a few weeks for design, permit and acceptance test

Time to install

Typically a day or two on site, plus the acceptance test

How it works

Fusible links in the hood, or linear or electronic detectors, trigger a release module that may be mechanical, pneumatic or electronic. Wet chemical — a potassium-based solution — discharges through nozzles aimed at each appliance, into the hood plenum and up the duct. On hot grease, the agent saponifies: it reacts with the fat to form a soapy foam blanket that cuts off air while cooling the oil. The release must also shut off gas or electricity to the cooking line. Some designs, such as Ansul PIRANHA, follow the chemical with a water spray for extra cooling.

Who needs it

Any commercial kitchen with cooking operations that produce grease-laden vapours — fryers, griddles, char-broilers and similar under a hood.

Codes, standards and listings

Canada: The National Fire Code and National Building Code of Canada reference NFPA 96; systems listed to ULC-ORD-C1254.6.
United States: NFPA 96 requires automatic fire extinguishing for cooking that produces grease-laden vapours; systems installed to NFPA 17A and listed to UL 300.

What the market looks like

Sold only through manufacturer-authorised, factory-trained distributors who design, install and service the system; Ansul and Amerex both route buyers to distributor locators. Main makers are Ansul (R-102, PIRANHA) and Pyro-Chem (Kitchen Knight II), both Johnson Controls brands, plus Amerex, Kidde Fire Systems (WHDR), Buckeye and the hood maker CaptiveAire. A 2025–2026 cost guide puts a small cookline at about USD $3,500–$7,000, mid-size at $7,000–$12,000 and large or multi-hood at $12,000–$25,000+.

Features that actually matter

Appliance-specific nozzles: Each nozzle is placed for a particular appliance in a particular position. Move the fryer and the coverage no longer matches.
Fuel shut-off: Discharge must cut gas or electric supply to the cooking line so the fire is not re-fed.
Release options: Fusible-link mechanical release is the traditional design; pneumatic and electronic detection are offered by Amerex and others.
Water-assisted designs: Ansul PIRANHA adds a water spray after the chemical for cooling.
Listed to UL 300 / ULC-ORD-C1254.6: These are the key tests for restaurant systems. UL 300 replaced the older dry-chemical hood systems.

What it really costs

Up front: Small cookline about USD $3,500–$7,000 (≈ CAD $4,800–$9,700); mid-size USD $7,000–$12,000 (≈ CAD $9,700–$16,600); large or multi-hood USD $12,000–$25,000+ (≈ CAD $16,600–$34,500+). Example: an Ansul R-102 on a 10 ft hood at about USD $10,400 for hardware and install, before permit and acceptance test.
Consumables: Fusible links replaced at least annually or semiannually per the manufacturer. Recharge after a discharge about USD $400–$900+ per hood.
What else you'll need: Permit and acceptance test, gas shut-off valve, the Class K portable extinguisher, and hood and duct cleaning to NFPA 96.
Over five years: Ten semiannual inspections at about USD $200–$500 each — roughly USD $2,000–$5,000 — plus link replacements, hood and duct cleaning, and any recharge.

Installed-cost planning ranges from a US cost-guide site, 2025–2026. CAD figures are converted from USD at ~1.38; we found no Canadian contractor pricing source. Get at least two local distributor quotes.

How it differs from the alternatives

Versus a Class K extinguisher alone: Not an option for commercial cooking that produces grease-laden vapours. The extinguisher is a backup, and the hood system must be activated first.
Versus old dry-chemical hood systems: UL 300 replaced them. Wet chemical works on modern high-efficiency fryers that hold heat longer.
Bundled with the hood: Kitchen ventilation contractors often supply the suppression system with the hood, which simplifies coordination but limits comparison shopping.

Buying it

Effort Moderate

Where: Not sold to end users — through manufacturer-authorised, factory-trained distributors who design, install and service it (Ansul and Amerex distributor locators, Pyro-Chem and Kidde Fire Systems distributors). Often bundled with the hood by the kitchen ventilation contractor.

Lead time: Days to a few weeks for design, permit and acceptance test

Use the same company for install and semiannual service where possible; they will know your nozzle layout.

Installing it

Effort Major project

Time: Typically a day or two on site, plus the acceptance test

You'll need: Contractor install

Not legally or realistically an owner install. The fire official usually witnesses the acceptance test.

Living with it

Effort Moderate

Semiannual inspection by a certified technician under NFPA 17A/96, fusible links replaced on the manufacturer's schedule, and hood and duct cleaning at a frequency set by cooking volume under NFPA 96. Tell your service company before moving or adding appliances.

If not this, then what

Class K wet-chemical extinguisherRequired as a backup, not a substitute.
Water-assisted designs (e.g. Ansul PIRANHA)Add cooling after the chemical discharge; ask your distributor whether it suits your line.

Caveats

Any change to the cooking line — a new fryer or moved appliances — requires the system to be re-evaluated, because nozzle coverage is position-specific.
A Class K portable extinguisher is still required near the cooking line, and the hood system must be activated first.
The agent is a corrosive alkaline potassium salt solution; expect clean-up and possible equipment damage after a discharge.
Manufacturer pages we checked did not display the UL 300 / ULC listing; confirm the listing with your distributor.

Our verdict

If you cook with grease commercially, this is not optional, and the main decisions are which distributor and which release type. Keep it inspected every six months, and treat every change to the cooking line as a call to your fire-system technician first.

We don't take payment for placement and we don't sell these products. If you think we've got something wrong here, tell us — we'll correct it.

Sources

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