Stena Line put the Ozonetech ozone treatment to the test for 12 months. We are happy they did!

Stena Line proved it. A correctly sized Ozonetech RENA system does keep the gallery duct clean.

It’s no secret the market trusts the Swedish ferry operator Stena Line. Their seriousness is well-known. When no other ferry company had installed our Ozonetech RENA ozone system, they decided to. And they did it in a way very few of our customers do: they set up their own 12 months test to see exactly what result the ozone treatment would have.


  • Name:

    Stena Line

  • Ferry name:

    Stena Danica

  • Length of ferry:

    155 m

  • Capacity:

    550 cars and 2,274 passengers

  • Location:

    At sea between Gothenburg and Fredrikshavn

  • Industry:

    Ferry operator

  • Purpose:

    Treating kitchen exhaust in galleys


  • Ozonetech RENA Kitchen Solutions

  • Dimensions (HxWxD):

    970 x 750 x 265 mm

  • Input power:

    1.5 kW

  • Noise level:

    49 dB

happy chef stiring and a buffet

The Stena Danica has several restaurants on board.

The problem

A fire starting in the galleys is disastrous. Manual duct cleaning to remove grease buildup is hard work, it’s time-consuming and requires planning. Still, the fire risk increases as soon as grease starts to build up again. With no effective continuous treatment, cleaning the galleys is costly and time-consuming.

Stena Line is one of the world’s largest ferry operators and known for being meticulous about quality and performance. When they contacted us, they were looking for a solution that would keep the galley ducts free from grease, reduce the risk of fire and minimize cleaning.

The solution

As a leading international ferry company, Stena Line decided to install an Ozonetech RENA system on-board Stena Danica. It took some planning, but when in harbor, the Stena Danica got its RENA system installed.

stena line and rena kitchen solution

The RENA system to the right includes ozone generator, oxygen-generator, closed cooling system, ozone sensor and the O3Eye control unit.


To see the long-term result, Stena Line decided to set up their own 12-month test to be certain about the long term efficiency. They cleaned an area inside the galley duct, to compare it to the areas still covered with fat. Stena finally reported a positive result: the cleaned area was still clean after the test period.

Galley duct testa area

No grease accumulated on the cleaned test area after 12 months. Test and photo by Stena Line.

When the Ozonetech RENA system had been installed, an area inside the galley duct was thoroughly cleaned and marked. Twelve months later the test area still looked clean. No grease build-up. The surrounding black spots are hard residues formed prior to the installation of the RENA system.