Frequently Asked Questions

Both the Smoke Zapper and Maxi Grill systems are installed in-line of the commercial kitchen grease duct system; i.e. the chimney. Each unit features an intake and an exhaust port for connection to the duct system. The duct system must terminally exhaust to the exterior environment.

Smoki® units are wet scrubbers. Wet scrubbers operate by exposing the dirty exhaust gas stream to a liquid - in this case, a multi-layer curtain of aerosolized water. Wet-scrubbers are a well-studied technology that can typically be found in use in large-scale industrial applications. The Smoki® innovation is based upon shrinking this effective technology to an appropriate size for commercial kitchen applications.

In independent field tests on wood-fired pizza ovens in New York City in 2016, the Smoke Zapper 200 reduced particulate matter by 93.75% (a test supervised by NYC DEP) and the Smoke Zapper 250 by 86.95% (NIOSH method 0500). Both results are well above the 75% reduction NYC DEP used as its benchmark for these tests.

Read the full reports: Smoke Zapper 200 field test and Smoke Zapper 250 field test.

Yes, substantially. In UL 1978 testing, 500°F gases entering a Smoke Zapper 250 left the unit at about 124°F, a drop of roughly 75%. See Cooling of Flue Gases by the Smoke Zapper.

It can, when the oven chimney is connected directly to the unit. Creosote condenses wherever flue gases fall below about 250°F. A hood over the oven mixes in cooler make-up air, which lets creosote form in the duct beyond the hood. With a direct chimney connection and the Smoke Zapper installed as close to the oven as possible, gases stay above 250°F until they reach the unit, which then cools them and deposits the creosote in its water tank, to be drained away.

UL 2162 and Chapter 14 of NFPA 96 both provide for directly connected chimneys on solid-fuel ovens. More in Creosote Reduction with a Direct-Connected Smoke Zapper.

Exact cost will vary per locale and Smoki® unit size, but in general, the utility cost is low. All Smoki® units require approximately 9 gallons of water per hour; in comparison, the average residential dishwasher uses about 6 gallons of water per load.

For example, in New York City as of 2019, the fresh water and sewer cost of 1 gallon of water is 1.4¢, according to NYC.gov. This means that 1 hour of operation should incur approximately 12.6¢ in water and sewer bills - or in one 10 hour day, about $1.26.

In the New York City metropolitan area, according to the Bureau of Labor Statistics website, electricity cost approximately 21¢ per Kw/hr. The Smoke Zapper 200 consumes approximately 1.12 Kw/hr - which translates to a 24¢ electricity cost per hour - or in one 10 hour day, about $2.40.

Combined, the Smoke Zapper 200 in New York City would incur an electrical and water bill of approximately $3.46 per day, according to the linked figures.

It depends on how your appliance is vented. The Smoke Zapper connects directly to the chimney of an oven or other solid-fuel appliance. The Maxi Grill goes in the hood exhaust duct above grills, broilers and other open cooking lines. Our guide Choosing the right unit walks through it.

Maximum ratings: Smoke Zapper 200, 350 CFM; Smoke Zapper 250, 450 CFM; Smoke Zapper 300, 700 CFM; Maxi Grill 250, 1,200 CFM; Maxi Grill 350, 1,800 CFM; Maxi Grill 400, 3,700 CFM; Maxi Grill 500, 4,700 CFM; Maxi Grill 500 S, 6,200 CFM.

For the best results in heavy-duty applications, such as solid-fuel appliances or odor-heavy cooking, our shop drawings advise designing for an airflow at least 20% below the unit's maximum rating.

Often, yes. The Smoke Zapper creates its own draft, but where the total duct run exceeds 25 feet a fan should be specified to aid natural draft. Maxi Grill systems need a fan matched to the total static pressure and airflow of the hood system.

Either way, the fan must have an easily reached variable speed control and at least an IP54 protection class. Balanced airflow is essential: if the airflow exceeds the unit's maximum rating, it can't clean the smoke fully and may pull water into the duct. The engineer of record specifies and calibrates the fan; the shop drawing for each model has the full notes.

The Smoke Zapper 200, 250 and 300 and the Maxi Grill 250 and 350 run on single-phase 120 V, 60 Hz. The Maxi Grill 400, 500 and 500 S need three-phase power (208–230 V). A certified electrician connects the unit to local code. See the single-phase and three-phase wiring diagrams.

Operating weights (with a full water tank), from our shop drawings:

• Smoke Zapper 200 and 250: 354 lb
• Maxi Grill 250: 562 lb
• Maxi Grill 350: 686 lb
• Maxi Grill 400: 1,166 lb
• Maxi Grill 500: 1,517 lb
• Maxi Grill 500 S: 2,590 lb

The floor, roof or supports must be rated for the full operating weight. Dimensions for every model are on its shop drawing.

A mechanical contractor/HVAC installer that is recognized & certified by the local Authority Having Jurisdiction to perform commercial kitchen grease duct installations must perform the installation and connection of Smoki® units.

Yes, it can be. Smoki® USA has helped consult and provide units to retrofit installations around North America. Retrofit installations are typically more difficult than installations where a mechanical system has been initially designed to accommodate a Smoki® unit. Successful retrofit installations can be viewed on the references page.

Units can hang on a wall, sit on the floor, sit on the roof or be suspended from the ceiling. Install it as near to the cooking appliance as you can: this reduces particulate and grease build-up in the duct. Choose a spot that leaves easy, regular access for maintenance.

Per UL 1978 and NFPA 96, the minimum clearances to construction are 18 in to combustible, 3 in to limited-combustible and 0 in to non-combustible materials.

On the service side, leave 36 in for the Smoke Zapper models and the Maxi Grill 250, 40 in for the Maxi Grill 350 and 500, and 45 in for the Maxi Grill 400 and 500 S. Smoke Zappers also need 36 in above the unit for access to the water tank.

It is the side the service access panel is on, viewed from the inlet. Every unit is built for one side, so tell us the access side, along with the external static pressure, the required airflow and the fan specification, before your order can be released to production. Download the left- and right-hand shop drawing for your model.

Each unit needs a ½ in cold fresh water line and a direct drain to a grease trap. If the existing grease trap is inconveniently located, supply an external dedicated one. The drain line is the engineer's design, installed to local code:

• slope at least ¼ in per foot and avoid unnecessary 90° turns
• increase the pipe size if it joins other drain lines
• don't use P-traps in the grease drain line
• use heat tape where the drain runs somewhere grease could solidify

The fresh water supply should read about 1 bar (about 15 psi) on the unit's pressure gauge. If the supply reads above 1.5 bar, install a pressure reducer to bring it down to 1 bar. The 9 gallons per hour water use is based on 1 bar.

Our manuals recommend a water softener where hardness is above 20–25 French degrees (about 200–250 ppm).

Yes. Smoki® units are built for interior or exterior installation and are rated to operate from 14°F to 120°F. Outdoors, the Maxi Grill needs its insulated stainless steel protection panel.

Where the unit sees freezing temperatures, the electrician must heat-wrap the fresh water line up to the water filter pressure gauge. Don't turn the unit off below 32°F without first draining the tank, and if it will be off for more than 12 hours, wrap it in a protective material.

The exhaust duct should rise at least 2° from the unit's exhaust port onward, so condensation drains back into the unit. Where that isn't possible, install a water drain at the lowest point where water could collect in the duct. Join the chimney to the inlet and outlet ports with continuous welded connections.

Our maintenance guides call for a routine clean (drain the tank, wash it out, and for the Maxi Grill wash the filters) plus a deep clean every 3 months, scrubbing the tank walls with detergent and a brush. The installation manuals set out a fuller schedule: water filter and water change every 15 days, tank, drains and float arm every 60 days, and the water level switch every 6 months.

Download the Smoke Zapper or Maxi Grill checklist, and see our maintenance guide.

Yes. The Maxi Grill filters can be washed in the restaurant dishwasher. Heavy residue may need soaking in soapy water first. Reinstall them with the black arrows pointing in the direction of the airflow. See the Maxi Grill quick visual guide.

Probably not. After the unit is switched back on, it refills the tank first, which takes about 10 minutes. The pump then starts automatically. Make sure the water supply is turned on and the drain lever is closed (vertical).

On a three-phase Maxi Grill, if the pump runs but the pump pressure stays low, the phases may be wired in the wrong order. Have an electrician check the pump rotation.

This is usually debris jammed in the pump impeller. Turn the unit off, clear the debris, and test again. If it still doesn't turn, try rotating the impeller by hand; a qualified technician can then check the start capacitor. A pump seized by debris is a maintenance issue rather than a warranty fault. Step-by-step: CM10 pump troubleshooting.

No. Never run the unit without water. The unit fills automatically from its fresh water supply, so keep the supply turned on whenever the unit is on.

Use detergents made for stainless steel. Avoid bleach, abrasive powders and anything containing salt or sulfuric acid. To remove limescale, a diluted solution of acetic acid works well. Take care not to wet or damage the cables and electrical box.

Yes. Smoki® pollution control units are certified by UL to UL 8782 and ULC S647 (UL file MH60726) for the USA and Canada, and have been tested to UL 1978. See the UL certificate.

No. An approved automatic fire-extinguishing system is still required for the filter sections and the ductwork downstream of the unit, and it is not supplied with the unit. Smoki® housings are 300/400-series stainless steel with continuously welded seams.

New York City has its own rules for commercial char broilers and wood- or coal-fired cook stoves, and installations are filed with the Department of Buildings. Read our guide to NYC cook stove rules, or contact us for the current approval documents for your project.