McDonald’s in central Stockholm ensures effective and safe grease removal with ozone

McDonald’s Regeringsgatan replaced air-fed ozone solution with high-performance Ozonetech ozone generator, improving air treatment quality

As one of the pioneering fast-food chains, McDonald’s has more than 36,000 restaurants worldwide. In Sweden, there are currently over 190 locations, including the one located on Regeringsgatan, in central Stockholm. McDonald’s has been present on the Swedish market from 1973 and growing ever since.


  • Name:

    McDonald’s Regeringsgatan

  • Location:

    Stockholm, Sweden

  • Challenge:

    Removal of grease from exhaust air

  • Market:

    Kitchen Exhaust

  • Project value (USD):



  • Mellifiq delivery:

    Ozonetech RENA – Kitchen solutions

  • Performance:

    Removal of grease in flue duct, preventing grease from depositing on duct walls, reducing fire risk, online remote monitoring of system performance

  • Capacity:

    2,500 – 3,000 l/s

  • Solution dimensions, HxWxD (cm):



Located in the heart of Stockholm, the restaurant serves thousands of customers daily and the continuous production emits high volumes of greasy compounds along with the kitchen exhaust air.

McDonald’s Regeringsgatan was previously using an air treatment solution based on an air-fed ozone generator which over time was not sufficient to cope with the restaurant’s air treatment needs. The grease volume in the exhaust air was too high for such a system to remove efficiently, which consequently required more frequent manual duct cleaning, increasing maintenance costs and negatively affecting business profitability.

Treatment systems based on air-fed ozone generators are often a cheaper alternative. However, they pose additional risks besides thick grease deposits in the duct, in the form of ammonium nitrate, a byproduct which is highly flammable and has a high carbon footprint.


In order to address issues posed by both greasy compounds in the exhaust air and a deficient solution, the ventilation consultants, TQI, contacted Mellifiq for a high-performance ozone system. Vasakronan, the property owner, couldn’t be happier with our solution.

The high-performance Ozonetech RENA 60 ozone system that we provided is based on an oxygen-fed ozone technology, which has an incomparably higher treatment capacity and is much more energy efficient. On top of this, the system requires minimum maintenance and ensures that no hazardous byproducts are produced.

The Ozonetech RENA 60 ozone system, along with our online monitoring system, the O3Eye™, ensures high uptime and is also integrated to the internal management system of the property owner.


Our Ozonetech RENA Kitchen Solution currently ensures complete grease removal from exhaust air at the McDonald’s on Regeringsgatan. Furthermore, the Mellifiq delivery guarantees total compliance with the European regulations for commercial kitchen ventilation, EN 16282. 

Compared with the previous solution, the restaurant benefits now from increased safety, decreased risk of fire, sees much better results in the treated exhaust air, and has total control over the system performance. 

Besides this, the maintenance costs decreased significantly since grease deposits at a much lower rate on duct walls and byproducts from the previous treatment solutions no longer need to be handled.