Ozone Laundry Systems: How Cold-Water Ozone Washing Works
Commercial laundries in hotels, nursing homes and hospitals spend a large part of their budget heating water. Ozone laundry systems attack that cost directly: they dissolve ozone into cold water and use its oxidizing power to do part of the work that heat and chemicals normally do.
How an ozone laundry system works
A typical commercial system has four parts. An oxygen concentrator feeds nearly pure oxygen to an ozone generator, where a high-voltage electrical field converts part of the oxygen into ozone (O3). An injector then dissolves the ozone gas into cold water in a contact tank, and a sensor and controller keep the dissolved ozone at a set level. Any gas that does not dissolve is passed through a destruct unit before it can reach the room.
The ozonated cold water is piped to the washers and used in the wash and rinse steps. Hot water stays connected for loads that still need it.
Why ozone helps in the wash
- It works in cold water. Ozone is a strong oxidizer at room temperature, so many loads can be washed without heating the water to 160°F.
- It opens up fibers and loosens soil, so detergent can work faster and fewer rinse steps are needed.
- It breaks down quickly back into oxygen, leaving no chemical residue in the linen or the drain water.
Reported savings
Manufacturers and laundry trade publications report hot-water and energy reductions of 65–95%, shorter wash cycles, one or two fewer rinses, 10–30% lower water and sewer use and longer linen life, with payback often quoted at 12–18 months. Treat these figures as vendor-reported: results depend heavily on the type of soil, the volume of the laundry and how well the system is set up. Ask any supplier for measured results from a laundry similar to yours.
What ozone does not do
- Ozone is not a detergent. Heavy oil and grease (kitchen towels, mechanic rags) still need hot water and conventional chemistry.
- Badly designed systems cause problems. Injecting ozone gas directly into a washer without proper dissolving can leave free ozone in the air and corrode equipment.
- It needs supervision. Your chemical supplier must adjust the wash formulas, staff must be trained, and the generator, sensors and destruct unit need regular maintenance.
Is ozone laundry accepted in healthcare?
Yes. In guidance developed with the CDC, the U.S. Centers for Medicare & Medicaid Services (CMS) lists ozone laundry systems as an acceptable laundering method for nursing homes when they are used according to the manufacturer’s instructions. Hot-water washing (above 160°F for 25 minutes) and low-temperature washing with suitable chemicals remain acceptable as well.
Checklist before you buy
- Dissolved-ozone control with a sensor, not just a timer
- An ozone destruct unit and an ambient ozone monitor with alarm in the laundry room
- Materials rated for ozone (stainless steel, ozone-resistant seals and tubing)
- Wash formulas agreed with your chemical supplier
- A service contract and measured results from a comparable installation
Room air must stay below the OSHA workplace limit of 0.10 ppm ozone averaged over 8 hours, so ventilation and monitoring are part of the installation, not an extra.