View Full Version : Replace R407c with R134a in Donaldson CQ0850ab air dryer?

02-12-2013, 10:45 AM
On a very remote minesite that I work at we have a Donaldson CQ0850ab air dryer. Now the unit needs re gassing and the ID plate shows that it takes R407c refrigerant (1.7kg) which would be fine if we had some one ticketed to handle the R407c. We have lots of guys ticketed for R134a. Is thier a problem with substitution of the r407c with R134a? I havent asked the Manufacturer yet or made the suggestion to my work collegues who have totally given up on having the unit re gassed. As I never like to open my mouth on subjects I have totally no idea about. So all I need is a few tips or ideas, any problems we may incur or if this is the dumbest thing you have ever heard. Please be gentle and help me sound intelligent. Cheers clint

02-12-2013, 11:08 PM
R407C machines are generally smaller than R134a machines and can have 20-35% more capacity forvthecsame amount of energy.

They have different operating temperatures/pressures.

Is the expansion device suitable?