Atrium Ljungberg and O’Learys chose ozone to recover heat

The grease is eliminated, and the heat is recovered to be reused in the property

The Swedish property owner Atrium Ljungberg was an early adopter of ozone treatment in kitchen ducts. The technology is today installed in more than ten restaurants in their properties, including O’Learys in Farsta, in southern Stockholm, Sweden. Most of the restaurants recover the heat energy.

Large real estate companies were pioneers in ozone purification. They own the premises and normally takes all the costs for their tenants’ energy consumption. If you, as Atrium Ljungberg, owns properties worth SEK 30 billion, each percent reduced consumption is valuable.

Atrium Ljungberg has today installed our Ozonetech Rena Kitchen Solutions in many restaurants in their properties. They chose our technology because it is effective and reliable. Ozone systems require no maintenance from the property owner.

The goal for Atrium Ljungberg is to install heat recovery in all properties with installed ozone treatment. The strategy is easy to understand. They simply want to reduce the total operating cost per square meter in their property portfolio.


  • Name:


  • Location:

    Farsta, Sweden

  • Industry:

    Sports restaurant

  • Purpose:

    Air purification and energy recovery


  • Ozonetech RENA Vivo B-series

  • Dimension (HxWxD):

    400 x 400 x 200 mm

  • Input power:

    1 kW

  • Noise level:

    49 dB

The interiour of the O’learys restaurant in Farsta, Stockholm.

The problem

In 2011 the venue in Farsta, Stockholm was being rebuilt for O’Leary’s new restaurant. In June the same year, two small air-fed ozone generators were installed to remove the grease and odor in the exhaust air before it is released into the environment.

During the years 2013-2014 the property owner Atrium Ljungberg decided to reduce their energy consumption by among other things utilize heat recovery from the extract air from the restaurant kitchen.

Since the restaurant at O’learys serves hamburges which requires a lot of friyng, they need an air purification system that would be able to handle the grease load. Although the property is not owned by the restaurant chain O’learys, there are often recommendations in the chains’ environmental policy that they should work to reduce their total environmental impact.

Kitchen duct with traces of grease on

The air treatment takes place in the kitchen ducts above the frying surfaces. The fat particles are broken down in 3-5 seconds.

The solution

To meet the requirements for both heat recovery and cleaning the greasy extract air the two air-fed ozone generators were replaced by an oxygen-fed Ozonetech RENA Kitchen Solutions. Atrium Ljungberg also upgraded to Service Agreement Premium including remote monitoring, free replacement parts and lifetime product guarantee.

Ozonetech rena high performance system

The high-performance Ozonetech RENA Kitchen Solutions reduces the risk of fire, removes odors and makes heat recovery possible.


A year after installation, everything works well. The grease in the ducts is eliminated and the heat is recovered and supplied to the property. The Ozonetech ozone system is remotely monitored around the clock and requires minimal service and maintenance. Both Atrium Ljungberg and O’Learys have achieved an efficient, reliable solution with very low environmental impact.

The Swedish fast-food chain O’Learys has installed ozone treatment in many of its restaurants – just like other global fast-food giants.

portrait of a man smiling in camera

Thomas Bahar, who together with his brother Bino Bahar owns and operates several O’Learys in Stockholm.

It was the property owner Atrium Ljungberg who made the decision to install the air treatment. We fry a lot of burgers, so the treatment is very useful. The air purification is running all times, we don’t need to be involved at all.

– Thomas Bahar, owner of the O’Learys restaurant