Why is the Capillary length of R134a more than one using R12?
Capillary length for a particular bore is dependent on the condensing and evaporating pressures and the mass flow and the transportation properties of the refrigerants. In this case the condensing pressure for 134a is about 10 to 15% higher than that for R12 whilst the evaporating pressures are lower than that for R12. The mass flow of 134a is lower than that for R12 while properties like viscosity etc are different. All these reasons lead to the capillary length for 134a being higher than that for R12.
