What is the AC Receiver Dryer?
The AC receiver drier is a component that only appears in air conditioning systems that employ expansion valves. The cylindrical component is seen between the condenser outlet and the expansion valve inlet. To understand what an AC receiver drier does, one must have a basic understanding how their car’s air conditioner works. Yes, it transforms hot air to cold. But there’s more to it. It does so by circulating a refrigerant that changes phase from liquid to gas and back again when forced through the system. The cold liquid refrigerant is squeezed through an evaporator, removing heat from air pulled in from the car’s cabin. Once cooled and dried, a blower pushes the air back out into the car. The warmed and vaporized refrigerant circulates through a compressor, where the vapor is cooled and transformed back into a liquid. And the process is repeated, over and over again, until you shut the AC off. The receiver drier serves as a filter to remove any moisture and contaminants that get into the AC system during this process.
ACR Drier has three parts:
- The Container: Acts as a temporary storage for oil and refrigerant during periods of low cooling demand.
- The Desiccant Sack: Usually filled with silica gel, it removes moisture from the refrigerant. It also traps other debris, preventing clogs.
- Inlet / Outlet: Lets the continuing flow of refrigerant around the system.
Bear in mind:
Think of the receiver drier in the same vein as you would fuel, oil, or an air filter: it is strictly a disposable. By that, we mean that it’s a necessity that can be easily replaced at a relatively affordable cost to you. Receiver driers rarely fail on their own. When a failure does happen, but, it is usually due either to clogging from debris inside the AC system (like from a failing or failed compressor), or that the desiccant bag has broken open, allowing it to circulate throughout the system, mixing with the refrigerant and lubricant.
How to Fix:
- The A/C system refrigerant is removed
- The A/C receiver drier is removed and replaced with a new one
- The A/C system is evacuated for 30 minutes
- The A/C system is recharged with the proper amount of refrigerant
- The system is checked for proper operation
The receiver drier must be changed each time your mechanic opens the system for service. Most compressor warranties require it. At the very least, it should be changed every three years.
Common signs indicating you may need to change the AC Receiver Dryer:
Unusual sounds while the system is running
Wide variances in cabin air temperature
Importance of this service:
Moisture kills an air conditioning system. Once inside, it combines with refrigerant, forming hydrochloric acid, which is extremely corrosive to metal parts. So changing the receiver drier is vital when servicing the air conditioner. If you change any component of the system you must also change the receiver drier. If you do not, there could be serious damage to the other parts of the system, which could be very costly in the long run.