Cold Plasma vs. Ozone Generators

If you have shopped for air treatment, you have probably seen ozone generators sold for odor removal. Cold plasma units like AURA also involve ozone, so it is fair to ask what the difference is. It comes down to one thing: whether ozone is the tool, or a byproduct that gets controlled.

What an ozone generator does

An ozone generator makes ozone on purpose and releases it into the room as its main treatment. Ozone is a strong oxidizer, which is why it can knock down odors. The problem is concentration. To work on odors, ozone generators can push indoor levels well past what is considered safe to breathe, and the U.S. Environmental Protection Agency advises against using them in occupied spaces.

That is why professional ozone treatments are done in empty spaces, followed by airing out before anyone returns.

What cold plasma does differently

Cold plasma uses electricity to briefly energize air inside a small chamber. That creates a mix of short-lived reactive molecules from the oxygen, nitrogen and moisture already in the air. Those molecules do the work: they break down certain odor molecules and VOCs, charge fine particles so they settle or are caught by your filters, and can inactivate certain microbes under tested conditions.

A small amount of ozone forms along the way, as it does with any process that energizes oxygen. In AURA, treated air passes through a catalytic control element that converts ozone back into ordinary oxygen before the air leaves the unit.

The numbers that matter

• Below 0.01 ppm: AURA’s ozone design target at the outlet with the BOOST dial off.
• 0.1 ppm: the U.S. OSHA workplace exposure limit, averaged over an 8-hour shift.
• Above 0.5 ppm: possible with AURA’s BOOST dial on, which is why BOOST is for trained personnel in unoccupied spaces only.

Side by side

• Ozone’s role: the main treatment in an ozone generator; a controlled byproduct in AURA.
• Occupied spaces: the EPA advises against ozone generators; AURA is designed for continuous use around people and pets with BOOST off.
• What does the work: ozone alone, versus a mix of short-lived reactive species.

How to tell what you are buying

Ask any manufacturer three questions:

1. Is ozone the main treatment, or a byproduct?
2. What is the ozone level at the outlet in normal use, and how was it measured?
3. Is the unit designed to run with people in the room?

Clear answers to all three are a good sign. Vague ones are worth a second look.

The bottom line

Ozone generators and cold plasma both rely on oxidation, but they are built for different situations. An ozone generator is a tool for empty spaces. AURA is designed to run quietly in the cabins, rooms and offices people actually use, with ozone kept in check.

Read our ozone guide, see our lab results, or request a consultation.

Results vary with space size, airflow, installation and use. AURA supplements HVAC filtration and ventilation; it does not replace them. Not a medical device; not intended to diagnose, treat, cure or prevent any disease. Ozone statements apply with BOOST off.