The VMUS-4 (VMUS-K) Ozone Generator produces 10 g/hr ozone from oxygen @ 4.0 LPM, or 4 g/hr from dry air.  Air cooled, wall mount ozone generator is very versatile and configurable for a wide variety of ozone production applications.  Ozone concentrations over 6% by weight are possible at low oxygen flow rates.

Rental Option HERE

10 In Stock

The VMUS-4 is an extremely flexible ozone generator able to produce ozone efficiently from either dry air, or oxygen feed gas.  Either vacuum operation or pressure is okay for the ozone generator cell.  Air cooled operation allows for use in many applications without the hassle of cooling water.  With the compact size and great ozone production, the VMUS-4 is a great value in ozone generators!

The VMUS-4 is a wall mountable Ozone generator which produces up to 10 g/hr of ozone @ 4 l/min of oxygen at over 3% by weight. Higher ozone concentrations are possible at lower oxygen flow rates. At 1 LPM the VMUS-4 produces ozone at 5.3% by weight. For full details on ozone generator performance view our performance chart.

This generator utilizes corona discharge technology. The corona cell in the VMUS-4 uses a true quartz dielectric in a stainless steel shell. This provides maximum reliability and ability for future repairs if ever necessary. Every component on the VMUS-4 is replaceable or repairable for long-term operation in your facility

For lab or water treatment applications the VMUS-4 is a great option.  Ozone concentrations over 5% are possible at oxygen flow rates less than 1 LPM.  Ozone concentration is important to improve ozone solubility into water and increase potential dissolved ozone levels into water.

The VMUS-4 conforms to CSA C22-2 No. 61010-1 and UL 61010-1.


Key Features:

     -Produces Up to 10 g/hr ozone efficiently

     -Can also produce 4 g/hr ozone from dry air

     -Wall mountable

     -Flow meter is standard

     -Adjustable output Standard

     -Flow Switch Standard

     -Detachable power cord

     -Easy to install and operate

     -Powder coated Al. cabinet

     -Can operate under pressure or vacuum

     -Circuit protection equipped

     -Rebuildable ozone generator corona cell

     -120 or 220 VAC power, 50/60 Hz capability standard


Ozone Generator Options

Optional features shown in the ordering section are available for the VMUS-4 ozone generator, these are described further below:

4-20 mA input control - control output of ozone generator from 0-100% via a 4-20 mA input.  Additional  information on this in the adjustable ozone output section below.

External ON/OFF control - turn ozone generator ON/OFF via dry contacts from remote location.  Useful for system integration where some automation is required.

Internal air pump - small air-pump can be built into the VMUS-4 to push air through the ozone generator.  This is useful when the VMUS-4 is used with an air dryer to produce ozone and a motive flow source is required.  Such as, a bubble diffuser at the bottom of a water tank.

Disable Flow Switch - option to disable the integrated flow switch.  Useful for low-flow applications, where ozone production at flows below 1 LPM are required.


Integrated Flow switch

The VMUS-4 uses an integrated flow switch for simple and reliable automation. This switch will turn the ozone generator ON when feed-gas flow rises above about 1.5 LPM, and turn the ozone generator OFF when feed-gas flow drops below about 1 LPM. This provides some simple automation for your ozone system. When used with a simple venturi injector the VMUS-4 will turn ON and OFF automatically based on suction from the venturi. When used with an oxygen generator the VMUS-4 will turn ON and OFF automatically when flow starts or stops from the oxygen generator. This feature eliminates the need for external wiring or flow/pressure switches.

When the ozone generator is turned OFF due to no flow, the No Flow light illuminates indicating this. When the flow is present this No Flow light will go out, and the blue Ozone light will illuminate, indicating ozone is now produced.

This flow switch can be disabled by choosing the "Disable flow-switch" option when purchasing.  There is no cost difference on this option.

ozone generator output selector

Adjustable Ozone Output

The VMUS-4 uses a digital adjustable ozone output shown in the image above. This will allow setting the ozone output from 0-100% using the rocker switch. Green status lights will show the current power setting of the ozone generator clearly and easily. The ozone output can also be adjusted while the ozone generator is in a No Flow status and not producing ozone.

Ozone output can also be adjusted via 4-20 mA input.  This allows adjustment of ozone output via a PLC or another device for automated operation.  When this option is chosen the keypad is overridden as long as the 4-20 mA is connected, if the connection is terminated the keypad is functional again.  Ozone output is displayed via the green LED indicators on the touchpad with the 4-20 mA input or the pushbuttons.

Circuit Protection

The VMUS-4 uses a sophisticated power inverter board that will protect the corona cell and/or transformer against failure. In the event, the corona cell does become contaminated with moisture, or dust the inverter will turn OFF ozone production immediately to protect against damage. Every 6 seconds this inverter will attempt to produce ozone and will restart automatically when conditions improve. While we hope our customers never flood, or contaminated the ozone generator corona cell, we know this is a possibility, this circuit protection will prevent potentially costly repairs.

Rebuild-able Corona Cell

The VMUS-4 corona cell is completely rebuildable. The Quarts dielectric can be removed from the stainless steel shell and be cleaned, or replaced if necessary. We know that air dryers, oxygen concentrators, and check valves can fail. Therefore we provide an easily rebuild-able corona cell so that these external failures do not have to be fatal to your ozone generator.

VMUS-4 Ozone Generator corona cell

        VMUS-4 Corona Cell

The most common failure of any ozone generator is poor feed-gas quality, either wet air, or poor quality oxygen. The VMUS-4 ozone generator corona will get dirty, wet, and full of contamination, however, the fundamental components of stainless steel and quartz are still good and can be disassembled, cleaned, and put back into service in even some of the worst cases.

VMUS-4 Ozone Generator corona cell

        Disassembly of corona cell (For a video explaining corona cell disassembly, please click here)


The VMUS-4 Corona cell consists of very few components. The Stainless shell and quartz dielectric are the main components.  Each end is sealed with a Kynar end cap that has the fitting molded in (fewer leak points) with a Viton O-ring and Kynar sealing ring.  We stock and sell all replacement and repair parts for the VMUS-4 ozone generator.  Therefore, you can be confident that no matter what happens your ozone generator will be repairable.


Ozone Production from Oxygen:

O3  Output       
O2 Flow       O3 Concentration
2.0 g/hr 0.35 LPM 95 g/m3
2.69 g/hr 0.5 LPM 89.6 g/m3
3.87 g/hr 0.75 LPM 85.9 g/m3
4.78 g/hr 1.0 LPM 79.6 g/m3
6.29 g/hr 1.5 LPM 69.9 g/m3
7.67 g/hr 2.0 LPM 63.9 g/m3
8.73 g/hr 2.5 LPM 58.2 g/m3
9.4 g/hr 3.0 LPM 52.2 g/m3
10.92 g/hr 4.0 LPM 45.5 g/m3
11.97 g/hr 5.0 LPM 39.9 g/m3
12.67 g/hr 6.0 LPM 35.2 g/m3
15.54 g/hr 10 LPM 25.9 g/m3
16.92 g/hr 15 LPM 18.8 g/m3

 Information on ozone output vs ozone concentration

Click on the images below to see complete performance data for the VMUS-4 Ozone Generator



Optional Enclosure:

The NEMA 4 enclosure option provides protection of the VMUS-4 ozone generator in hostile and wet environments.   The clear cover allows for easy monitoring of display on the ozone generator or dryer.   A fan draws cooling air through a slash-resistant vent and filter in the bottom and blows out a splash-resistant vent and filter on the side.   Cord grips seal around the feed gas and ozone tube connections.  The VMUS-4  can be easily removed for service.  An internal outlet is used to power the fan and the ozone generator.  Fan is on continuously when the unit is powered.  

Enclosure can be mounted to wall either with anchors through 4 holes accessible from the inside, or using optional mounting tabs at each corner.   
Material Polycarbonate
Composition Non-Metallic
Number of Doors 1
Cover Design Hinged
Window/Clear Cover Yes
Latching Mechanism Latch
NEMA Rating NEMA 4
H x W x D 21 x 17x x8
Weight 10 lbs



VMUS-4 Performance Chart showing maximum ozone production

VMUS-4 Ozone generator output chart


VMUS-4 Performance Chart showing each ozone output set-point production

VMUS-4 ozone generator output at all 10 output settings

Click HERE for information on how to read and understand ozone generator performance charts

Click HERE for information on how we test ozone generator output

Ozone Generator Feed-Gas, Oxygen vs Air compared


Ozone Production from Dry Air:

O3  Output   
Air Flow     O3 Concentration
1.28 g/hr 2 LPM 0.8 %
2.19 g/hr 4 LPM 0.68 %
2.88 g/hr 6 LPM 0.6 %
3.3 g/hr 8 LPM 0.52 %
4.0 g/hr 10 LPM 0.5 %

 VMUS-4 Ozone Generator performance Chart on dry air

*Click on image for larger view



Using the VMUS-4 with Oxygen:

We provide a variety of oxygen concentrators that could be used with the VMUS-4.  Our recommendation would be the MAX-5. The MAX-5 will produce 4.9 LPM of oxygen, this is sufficient for a full 10 g/hr of ozone production from the VMUS-4.  The oxygen pressures flow and general operation of the MAX-5 will be a great fit with the VMUS-4.  However, if you choose to use your own oxygen concentrator, simply contact our office and let us ensure it is the right fit for your application.

Keep in mind that ozone generated from oxygen will be generated at a high concentration, and will, therefore, dissolve into the water more efficiently.  Therefore, if using ozone to be dissolved into water consider using an oxygen concentrator first.

VMUS-4 Ozone Generator with OXUS-8 Oxygen Concentrator

 Click on image to enlarge


Using the VMUS-4 with Dry Air:

The VMUS-4 Ozone Generator can operate under vacuum.  Using the VMUS-4 with the VMD-8 vacuum-driven air dryer is a simple method of dissolving ozone into water.  A venturi injector can be used to create a suction of gas into a water stream.  The ozone generator and air dryer can be plumbed in series so that the dry air is pulled through the ozone generator and into the water via the venturi injector.  There will be no major moving parts and simple, reliable operation.

VMUS-Ozone Generator with air dryer Click on image to enlarge




The wall dimensions and wall bracket connections on the VMUS-4 Ozone Generator. Please note this is listed in centimeter (cm).

 Dimensions of the VMUS-4 Ozone Generator (in cm)

Replacement Parts:

kynar o ring for electrode  housing
kynar o ring for electrode  housing

Kynar nut for Kynar head


kynar head for electrode housing


VMUS-4 Corona Cell

Nipple fitting










K Series Brochure

VMUS-4 Ozone Generator Manual

VMUS-4 when used with VMD Air Dryer Manual


Ozone Generator Information:

Ozone Generator Buyers Guide

Ozone FAQ's

How is ozone produced from Corona Discharge

Ozone Generator Feed-Gas, Oxygen vs Air compared

Measure ozone production from an Ozone Generator

How to read and understand an ozone generator performance chart

Ozone Generator Output vs Concentration



Common Applications:

     -Ozone in water application for water treatment

     -Ozone in swimming pools

     -Laundry applications


    -Well water treatment

     -Bottled water

     -Laboratory applications


Review from Oxidation Tech:

The VMUS-4 is an extremely versatile ozone generator capable of operating from oxygen or dry air, and under a pressure or vacuum.  This allows the VMUS-4 to fit a wide variety of applications.  With the most recent updates to the VMUS-4 in 2017 the form, function, and reliability are second to none in this price and size range.  The VMUS-4 is a reliable machine will all replaceable parts.  We have successfully serviced units over 10 years old that are still in operation today, and with the newest updates, we feel the latest VMUS-4 is the best yet.

Due to the flexibility of the VMUS-4, it can be used in most any ozone generation application.  This is one of the few ozone generators available that can efficiently produce ozone from dry air, or oxygen, at pressure, or vacuum.  This flexibility along with the wall mounting configuration make this a great ozone generator for many applications.

VMUS-4 Overview:


VMUS-4 Flowmeter and Flow Switch operation:


Creating Ozonated Olive Oil with the VMUS-04 :


More Information
Quickbooks Stock Level 10.000000
Call For Price No
Ozone Output 10 g/hr ozone from oxygen, 4 g/hr ozone from dry air - 10 g/hr ozone from 4 LPM oxygen @ 3% by weight - 4 g/hr ozone from 10 LPM dry air @ 0.5% by weight
Feed Gas O2 or Dry Air
Nominal Gas Flow Rate 4 LPM oxygen to produce 10 g/hr ozone
Operating Pressure 5 PSI
Max Pressure 5 PSI
Manufacturer Azco
Cooling Method Air Cooled
Corona Cell Quartz , Stainless Steel
Gas Connections 1/4" barbed fittings
Dimensions (LxWxH) 3.5" x 10" x 17"
Operational Temperature Range 35 - 95-deg F
Max O3 % 5% - 7.5%
Power Requirements 120 or 220 VAC, 50 or 60 Hz, 120 watts
Lead Time 2-Weeks
Warranty 1 Year
Country of Origin Canada
Description Enclosure Dimensions: 17-inch height x 10-inch width x 3.5-inch depth Generator Weight: 15 lb
Unit Features

Ozone Output: 

- 10 g/hr ozone from oxygen, 4 g/hr ozone from dry air   

- 10 g/hr ozone from 4 LPM oxygen @ 3% by weight     

-  4 g/hr ozone from 10 LPM dry air @ 0.5% by weight

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