Compared to R-22, R-410A has outstanding liquid sub cooling performance. Modern R-22 air conditioning system liquid lines are typically sized for a maximum pressure drop of 30 PSI from the outlet of the condenser to the inlet of the metering device. To overcome this pressure loss and deliver a sub cooled liquid to the metering device, manufacturers must be able to
produce 10 degrees of liquid subcooling in their condenser coils. R-410A refrigerant with 10 degrees of liquid subcooling can overcome up to 50 PSIG of liquid line pressure drop. This subcooling performance is significantly better than R-22.
Where this advantage will be useful is in applications where the existing R-22 line sets must be reused with R-410A systems. Although the pressure and velocity of the R-410A liquid will result in greater pressure drop in the liquid line, the refrigerant will be able to overcome greater pressure
drop. This unique feature of R-410A gives contractors greater flexibility in replacing existing R-22 systems when there are no more R-22 systems available.