Hose development for use of new coolants

Research and Development

Directive 2006/46/EC replaces EC directive 70/156/EEC and governs the type approval system for commercial vehicles. Among other things, this contains regulations for safety-related components, as well as certain environmental constraints, such as those for CO2 emissions.

Use of alternative coolants is mandatory for complying with directive 2006/46/EC, because the currently used coolant R134a exceeds the GWP limit tenfold. The GWP (Global Warming Potential) indicates a substance as potentially damaging to the climate if its maximum value is 150 according to EU guidelines.

The competition for the future of coolants has not yet been settled: both R1234yf and R744 are in testing but have not yet reached the home stretch.

R1234yf: (GWP = 4.4)

The PHX H3 hose currently used with R134a meets the functional and material requirements for air conditioning units designed for R1234yf. However, since major German vehicle manufacturers have detected flammable, explosive, toxic hydrofluoric acid during legally mandated crash tests, use of this coolant is controversial. Nonetheless, use of the chemical R1234yf will not be avoidable and sooner or later will be in AC systems.

 

R744: (GWP = 1)

Use of natural R744 in air conditioning systems requires a great deal of pressure and temperature resistance. Meeting these demands requires use of some additional corrugated pipes in the duct system and new hose components that are resistant to R744. Use of air conditioning systems with R744 is planned for 2015 at the earliest.

Kältemittelschlauch PHX H3

Use of natural R744 in air conditioning systems requires a great deal of pressure and temperature resistance. Meeting these demands requires use of some additional corrugated pipes in the duct system and new hose components that are resistant to R744. Use of air conditioning systems with R744 is planned for 2015 at the earliest.

Duct systems for the coolant R744 (CO2)

Duct systems for the coolant R744