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About Novozone, ozone basics and ozone calculations

Our mission

Our mission is to bring to market safe eco-friendly water and air sanitizing solutions. Ozone produces no disinfection byproducts (DPB’s) and is environmentally safe.
With headquarters, sales, projects and production facilities in Albany on Auckland’s North Shore, Novozone proudly upholds New Zealand’s clean and green reputation.

About Novozone

Novozone offers project engineering, consulting, service and a wide range of commercial grade and domestic ozone products.

Novozone is a system integrator with 15+ years of experience in a wide variety of applications using ozone.

Novozone has sold more than 11,000 ozonators in commercial and domestic applications.

We are resellers for the Oxidation Technologies and Wassertec range of products.

Our expertise

In 1992, Novozone pioneered the development of a revolutionary corona discharge ozone cell. Novozone patented this new technology and soon began supplying a large number of ozone generators around the world.


Novozone can supply a full range of ozone generators, oxygen concentrators, automatic air dryers, ozone injection, mixing and contacting devices, oxidation-reduction potential (ORP) and dissolved ozone (DO3) monitors and controllers.
We also carry a wide assortiment of ozone resistant fittings and hoses.

Service and repair

Ozone is a powerful oxidiser. Ozone machines need to be regular serviced in order to maintain peak performance.

Email service(at)novozone(dot)co(dot)nz for your requirements.

We are proud to have the expertise, tools, test equipment and products to maintain these products in top condition. We even service our competitors’ products.
A properly maintained ozone generator used for commercial systems has a typical lifespan of 10 years.


Ozone generators are constantly evolving. In recent years with the use of new materials and electronics they produce high ozone concentrations at low oxygen flows. They have become more reliable, more maintenance friendly and therefore more cost-effective.

We welcome enquiries to upgrade your existing ozone system.

Our commitment

Put our extensive experience in the ozone field to work for you. We look forward to working with you and provide you with a product that meets your requirements and saves you money!.

Our warranty and trade policy

You can read our warranty policy and terms of trade policy here:

How ozone is made

Ozone is a natural gas, a tri-atomic form of oxygen.

Simply speaking, it is produced in the ozone generator which is supplied with air and and a little bit of electricity.

The electricity splits the oxygen in the air into two oxygen atoms. The oxygen atoms combine with oxygen molecules to form the ozone gas.


The weak bond holding ozone's third oxygen atom is what causes ozone to be a very strong oxidant and an ideal 'chemical free' sanitizer and oxidizer agent.

When oxidizing a compound it looses the weakly bonded atom and an oxygen molecule remains.

Lean more: Ozone101

Ozone approvals

Aqueous ozone is approved as a 100% natural, safe and efffective sanitizer and is approved by these agencies:


Ozone anti-microbial efficacy

This natural gas is 3,000 times more powerful than traditional oxidants like chlorine. It has no toxicity issues and produces no disinfection byproducts (DBP's). Micro organisms do not build up a tolerance to ozone.

Relative sanitizing values:
1 ppm ozone equates to 200 ppm chlorine

Strenght Product
200 ppm chlorine
25 ppm iodine
200 ppm quaternary ammonia
400 ppm hydrogen peroxide
125 ppm peroxyecetic acid
1 ppm ozone

Source: CFR 178.1010(b) (1,3,9,30,38) "Catergory Three Certification"

The efficacy of aqueous ozone to destroy pathogens is dependent on the ozone concentration in water (ppm) and the contact or 'treatment' time. This paper summarises the efficacy of aqueous ozone and time to destroy bacteria and viruses.

Lean more about ozone efficacy

Ozone safety

Ozone storage

Ozone is produced on-site by the ozone generator. Because of it's 'short' life (as it reverts back to oxygen), ozone cannot be supplied or stored in tanks. Safety requirements for storage and handling of dangerous chemicals (like chlorine) do not apply.

Ozone in water (aqueous)

Ozone has been allowed and accepted for some time in food processing in Japan, Australia, New Zealand and other countries. Ozone was confirmed as GRAS (Generally Recognised as Safe) by the FDA in 1998 and recently as a safe and sustainable sanitizer for food meant for human consumption.

Ozone in air (gaseous)

Ozone gas in the work place is subject to local governmental regulations. Typically Health & Safety regulations require that ozone levels in the workplace remain below 0.1 ppm.

Lean more about human tolerance for ozone

How is ozone introduced in water?

Venturi and diffuser injection

The ozone produced in a corona discharge cell is a gas. To produce ozonized water the ozone gas must be dissolved in the water.
Two popular methods are using a venturi injector or a diffuser.

Venturi Injection

Efficient ozone injection into the water is accomplished using the suction developed by a venturi injector in the water stream.
A pump forces the water through the venturi. Cavitation effect at the injection chamber provides instant mixing, creating thousands of tiny ozone bubbles resulting in efficient ozonation.
Venturi injectors have no moving parts, require a pressure difference between the inlet and outlet port to operate and are available to operate under a wide range of flows and pressures.

Diffuser Injection

Systems which bubble ozone into the water under pressure can be less efficient and generally less safe due to the potential for ozone leaks.
An air pump or compressor pumps the ozone gas in the diffuser creating thousands of ozone bubbles.
Diffusers have also no moving parts, require enough pressure to operate.

Ozone solubility in water

For ozone to disinfect water (or to oxidize iron) the ozone gas must be transferred in water. This process is defined by Henry's law and (simply stated) the higher the gaseous concentration is the higher the ozone concentration in the water will be.

High transfer efficiencies can be achieved with oxygen fed ozone generators which are able to produce high ozone concentrations. Novozone manufactures high concentration ozone generators with low oxygen flow requirements.

Lean more: Ozone Solubility

Venturi manifolds

For proper operation, an injector must operate within a specific flow rate and pressure differential range. This can be accomplished with a manifold assembly enabling the adjustment of the injector's flow with a bypass valve. This also allows the suction to be adjusted to the requirements of the ozone system.
A properly installed venturi injector can provide a 90+% mass transfer of ozone.

Off-gassing and destruction

High concentration ozone must be destroyed before it is vented to the atmosphere or work place as a safety precaution or to comply with health and safety regulations.

The mixing tank will usually have a degas valve allowing the off-gas to escape to atmosphere or through a destructor device which converts any ozone into harmless oxygen.

Mixing and contacting

After injection a mixing or contacting tank allows time for dissolved ozone to oxidize mineral and organic compounds and to disinfect the water.


The dissolved ozone concentration (C, in mg/L) multiplied by the time (T, in minutes) of contact between the dissolved ozone and the contaminants in the water provides a "CT" value. This value is used as an index to the effectiveness of the disinfection process. Ozone disinfection system generally achieve adequate disinfection with a CT value of 1.4 or greater.

Plug & Play Ozone Oxidization Systems

For many applications it is convenient to fit all the ozone components on a skid. This provides quick installation and commisssioning: Connect the water lines and you are ready to operate.

A skid would typically include the ozone generator fed from an oxygen concentrator (or automatic airdryer), a booster pump, injector to dissolve the ozone in the water, mixing tank and off-gas valve as shown below:


Plug & Play Iron Removal Systems

Iron and Manganese are rapidly oxidized by ozone. The precipitated Iron and Manganese is removed by an automatic backwash filter as shown below.

If an ozone based iron removal system is installed, the ozonized water can be used at no extra cost for water disinfection, teat wash to reduce mastitis, sanitizing milking machines, hoof bath at significant chemical cost savings.


Ozone calculations examples

Bottled water

The International Bottled Water Association (IBWA) recommends a 0.2 - 0.4 ppm residual in the bottle.

Assuming we have 'bottle ready' water with no additional demand for ozone then 1 gram of ozone will produce a residual of 1 ppm for every 1,000 Litres of water.

In practice the ozone transfer efficiency from the gas into the liquid phase is much less.

As an example, a small bottling plant bottles at 10,000 Litres per hour and wants a 0.4 ppm ozone residual. Assuming a 75% efficiency, an ozone generator producing at least 5 g/hr is needed.

Bottled water calculator



TOTAL O3 [g/hr]:

Swimming pool

Ozone systems for swimming pools are sized according to the pool water volume and bather load (and budget!).

For optimum water quality use these formulas as a guide:

Pool type Ozonator size [gO3/hr]
Spa Pool volume (m3) x 0.8
Kid's Pool volume (m3) x 0.14
Main Pool volume (m3) x 0.07

For example a 500 m3 main pool would require a 35 g/hr ozone system.

Other factors such as filtration, turnover, mixing and dead spots are to be considered.

Contact us to discuss your requirements
Potable water - Iron removal

In many rural communities the water source is rain and or bore water and is stored in a reservoir. Apart from pathogens, dissolved iron, manganese and hydrogen sulfide can frequently be found in bore water.

This calculator estimates the ozone requirements to take the iron, manganese and H2S out of solution, to disinfect the water and to maintain a 0.3 ppm ozone residual in a storage tank.

Potable water calculator






TOTAL O3 [g/hr]: