Automotive giant Daimler goes head-to-head with industry over flammable HFO 1234 yf
Carmaker Daimler has caused consternation in the industry by announcing it believes that HFO 1234 yf is more flammable under certain crash conditions than the refrigerant it was designed to replace R134a.
The move by Daimler, following the commissioning of a bespoke test that the carmaker said replicates the effects of a head-on collision, has inevitably sparked outrage in the refrigerant industry, which had believed that the safety arguments with the HFO in cars had been addressed.
At the same time, the move by Daimler to request permission from the European Commission to continue using R134a instead of the HFO has inevitably raised questions amongst rival automotive manufacturers and could force the EC to review its deadlines for the MAC (Mobile Air Conditioning Directive). The terms of the directive require a refrigerant with a GWP of less than 150, and R134a has a GWP of 1430, whereas 1234yf has a GWP of 4.
The two production partners for HFO1234yf, Honeywell and DuPont, have each moved to strenuously deny that there is any flammability risk with the refrigerant – designed specifically for mobile AC - which has not already been thoroughly addressed with carmakers. The gas is described as ‘mildly flammable’ but the refrigerant firms have always maintained that this would only ever ignite under extreme conditions – at a temperature of 750 deg C when the refrigerant is mixed with oil – and that R134a would ignite at exactly be the same risk for R134a.
As RAC went to press, Du Pont issued a statement saying that following further meetings with the carmaker, it remained confident in the results of its previous tests.
Diane Iuliano Picho, its global business manager, for the refrigerants said: “We met with Daimler to understand their testing approach and results, and based on these discussions, DuPont has concluded the testing does not represent new information.
It is well known that HFO 1234yf is a mildly flammable refrigerant. Extensive flammability testing was completed by independent globally recognised third-party laboratories. Multiple risk assessments by industry stakeholders, including Daimler, have thoroughly evaluated the product’s flammability, and have shown that there is no significant additional risk versus the current refrigerant.”