View Full Version : charge r404a into a system running on r139a

23-08-2014, 03:50 AM
what happens if i charge r404a into a system running on r139a .... the control air drier needs charging but it r139a system so want to know if i can charge r404a into it?

23-08-2014, 07:48 AM
You mean R134A?

23-08-2014, 01:27 PM
No you can't change if you not replace compressor and TXV for R404A/R407C-pressure range and make sure pipe etc. can work with higher pressure with enough safety margin.

Shift from R134a to R404A is same big steps as shift from R134a to R407C in pressure shift if you look on PT-chart of respective refrigerant.

If you still try with R404A without replace compressor and tune replaced R404A-TXV for full wetted evaporator, R134a-compressor going very overloaded depend this displacement per rev is almost double and make double loads of motor compare to R404-designed compressor with same size of motor

Play with http://coolpack.software.informer.com/ origin from Danfoss and this software package you can simulate cooling circuit with different refrigerant and also print out PT-chart on most common refrigerants and make compare between refrigerant.