This article addresses the common issue of pipe freezing in split-type air conditioners, a problem that can significantly impact system performance. It also explores potential causes and provides recommended solutions.
1. Configuration of the Split System
In a split-type air conditioning system:
- High-pressure pipes: Located within the outdoor condenser unit.
- Low-pressure lines: Both visible pipes outside are low-pressure lines.
- Primary pipes:
- Thin pipe (liquid line): Transports liquid refrigerant from the capillary tube to the evaporator to absorb heat from the surrounding environment.
- Thick pipe (vapor or gas line): Returns gaseous refrigerant from the evaporator to the compressor after absorbing heat from the indoor space.
2. Freezing in the Thin Pipe (Liquid Line)
Freezing in the thin pipe may occur due to:
- Refrigerant shortage:
- The working pressure of R32 or R410A should exceed 120 PSI.
- Low amperage consumption from startup indicates insufficient refrigerant.
- This issue does not cause cold concentration solely in the capillary tube.
- Capillary tube obstruction:
- The capillary tube may cool abnormally and freeze due to a blockage.
- This leads to progressively lower current consumption as the compressor compresses less refrigerant, which remains trapped in the condenser unit.
- The capillary tube temperature should be similar to the ambient outdoor temperature, not lower.
3. Freezing in the Thick Pipe (Vapor Line)
Freezing in the thick pipe is often linked to evaporator malfunctions, which are responsible for transferring refrigerant to this line. Primary causes include:
- Dirty air filters: Reduce airflow and impair evaporator performance.
- Dirty blower fan: Causes insufficient airflow.
- Low fan speed: May result from a defective capacitor, bearing issues, or motor failure.
4. Recommended Solutions
To address freezing issues in the system:
- Check refrigerant levels: Verify system working pressure and recharge refrigerant if necessary.
- Clean the indoor unit: Remove dirt from filters and blower fan to improve airflow.
- Inspect the fan motor:
- Test the capacitor and replace it if defective.
- Inspect and resolve motor bearing issues.
- Evaluate the capillary tube: If blockages are found, clean or replace the component.
