A blend of R-125, R-143a, and R-134a intended for low and medium temperature refrigeration applications where R-502 was previously used. Most new supermarket and refrigeration equipment has been built for an HFC such as R-404A, R-507, or R-407A. It is also possible to retrofit charge R-507 systems with R-404A. R-404A has slightly lower pressures than R-507 (from the small amount of R-134a added), and generally both blends have slightly higher pressures than R-502. R-404A requires polyolester (POE) lubricant, which is usually charged into new equipment. If retrofitting existing equipment, the original oil must be replaced with POE.
