The low presser refrigeration air dryer cools the incoming compressed air first in an air­to­air heat exchanger where the outgoing cool dry air pre cools the hot incoming air and condenses some moisture out.

Then the incoming air enters an air to refrigerant heat exchanger where the air is cooled to 38⁰F by the liquid refrigerant.

This process causes the moisture to condense into liquid water and it is drained away.

The outgoing air then enters the air­to­air heat exchanger and is warmed up to keep the outside of the pipes from sweating.