This can be a complicated question because there are many factors that effect your refrigerant pressures. Outside temperature, inside temperature, and humidity are just a few. To put it very simply, on a summer day with outside temp around 85, and inside temerature around 78; an R-22 system should run about a 75 psi suction and 225 psi head pressure. While an R-410a system will run around a 130 psi suction and 325 psi head pressure.
Tags: freon, gas