Belgium: Full-scale test for R33 passed

R33 has been used in 15 residential Belgian heating systems for almost a year. The test results are unanimous: this mixture of domestic heating oil, HVO and FAME is suitable for heating systems that are less than 20 years old.

A panel of 15 installations

In 2021, 15 installations (out of almost 1500 applications) were selected to participate in the field test carried out by Informazout, Eurofuel’s Belgian member. The choice was made for different brands of low-temperature and condensing boilers, all installed between 2006 and 2021. The selected homes were delivered with the alternative fuel from summer2021. As a reminder, the R33 mixture, which was tested by an independent laboratory before delivery, is composed of 67% domestic heating oil (NBN EN 590), and 33% low-carbon fuel, namely 26% HVO (NBN EN 15940) and 7% FAME (NBN EN 14514).

Successful test

Almost a year later, in the summer of 2022, the 15 installations had a new check-up to compare their operation with R33 to conventional heating oil. The focus was on the condition of the heating system and its exhaust gas parameters. During their operation with R33, no fuel-related heating failures were observed. There were also no technical problems with the burner hoses, pumps, filters, or flue gas ducts. The measured combustion values of the boilers also remain in accordance with the environmental regulations.


Reduction of CO2 emissions

Compared to the use of conventional heating oil, R33 reduces CO2 emissions by one third: conventional heating oil emits 267 g CO2eq/kWh (Hi), whereas the R33 used in this test campaign emits only 187 g CO2eq/kWh (Hi).  For a typical annual consumption of 2000 litres of liquid fuel in a home: R33 emits 3.74 tonnes of CO2 equivalent, against 5.34 for fossil heating oil. The 15 installations in the field test saved a total of 24 tonnes of CO2 equivalent. In Belgium, almost 1.5 million households could use R33, which means a potential reduction of 2.4 million tonnes of CO2 equivalent/year (based on the annual consumption of 2000 litres).


R33 can replace heating oil overnight in heating boilers that are less than 20 years old, without any technical modification or cleaning of the tank. Informazout has demonstrated that R33 works well in existing heating oil boilers. The next step is to create a legal and fiscal framework to introduce R33 to the market. At the level of fuel standards, the situation is similar to Switzerland, so integration of the low carbon fuel R33 into the existing Belgian standard for domestic heating fuel is an option. Boiler manufacturers could support market introduction by the publication of a list of approved boilers, or even their approval for the use of R33 in all boilers. Finally, fiscal incentives for the new fuel can help to accelerate the decarbonisation of oil heating. Low carbon fuels are the future of the sector.


"R33 can replace conventional (fossil) heating oil overnight in boilers less than 20 years old, without any technical modification or tank cleaning. Low-carbon fuels are the future of the sector”