Accumulator HVAC: Description and Operation

SUCTION ACCUMULATOR

NOTE: Installation of a new suction accumulator is not required when repairing the air conditioning system except when there is physical evidence of system contamination from a failed A/C compressor or damage to the suction accumulator.

A new suction accumulator should be installed if one of the following conditions exists:
- The suction accumulator is perforated.
- There is evidence of moisture in the system such as internal corrosion of metal refrigerant lines or the refrigerant oil is thick and dark.

The suction accumulator is mounted to the A/C accumulator bracket to the right of the vehicle centerline. The inlet tube of the suction accumulator is attached to the evaporator to accumulator suction line. The outlet tube attaches to the evaporator to compressor suction line.

After entering the inlet of the suction accumulator, heavier oil-laden refrigerant contacts an internally mounted dome (which serves as an umbrella) and drips down onto the bottom of the canister.
- A small diameter oil bleed hole, in the bottom of the vapor return tube, allows the accumulated heavier liquid refrigerant and oil mixture to re-enter the compressor suction line at a controlled rate.
- As the heavier mixture passes through the small diameter liquid bleed hole, it has a second chance to vaporize and recirculate through the A/C compressor without causing compressor damage due to slugging.
- A fine mesh screened filter fits tightly around the bottom of the vapor return tube to filter out refrigerant system contaminant particles.
- A desiccant bag is mounted inside the canister to absorb any moisture which may be in the refrigerant system.
- A fitting located on the top of the suction accumulator is used to attach the low charge protection switch. A long-travel Schrader-type valve system core is installed in the fitting so that the low charge protection switch can be removed without recovering the refrigerant.