Although it may go by several different names (filter/dryer, receiver/dryer, or accumulator), the dryer plays a key role in A/C system performance and longevity. The dryer is connected to the A/C refrigerant circuit and looks like a canister made of aluminium, which contains an internal moisture collector called desiccant. A receiver/dryer normally connects to the high side of the system. An accumulator usually connects to the low side of the system. Some systems may use both a receiver/dryer and an accumulator.
The A/C dryer removes water and some dirt from the refrigerant and also stores a certain amount of refrigerant as it cycles through the system. Some receiver/dryers have a sight glass mounted on top to aid in charging the A/C system.
An A/C Dryer does not require periodic maintenance. However, the dryer should always be replaced anytime the A/C system is opened for repairs.