Copper Pipe Sizes for Air Conditioning Systems

1. 1/4 inch (6.35 mm):
– **Application:** Typically used as the liquid line for smaller air conditioning units with a capacity of 1.5 to 2 tons.

2. **3/8 inch (9.52 mm):**
– **Application:** Commonly used as both the liquid line and suction line in medium-sized air conditioning units ranging from 2.5 to 4 tons.

3. **1/2 inch (12.7 mm):**
– **Application:** Versatile size used for both liquid and suction lines in various air conditioning units. Suitable for medium-sized units with a capacity of 2.5 to 4 tons.

4. **5/8 inch (15.88 mm):**
– **Application:** Often used as the suction line for larger air conditioning units with a capacity of 4 to 5 tons.

5. **3/4 inch (19.05 mm):**
– **Application:** Commonly used for the suction line in larger residential air conditioning units and commercial systems.

6. **7/8 inch (22.23 mm):**
– **Application:** Typically used as the suction line in larger commercial air conditioning systems with a capacity of 5 tons or more.

### Important Note:
– The sizes mentioned here refer to the outside diameter (OD) of the copper pipes.
– Both liquid and suction lines are part of a split air conditioning system where refrigerant flows between the indoor evaporator unit and the outdoor condensing unit.

When choosing copper pipe sizes, it’s essential to consider the manufacturer’s specifications for the specific air conditioning unit. Additionally, local building codes and regulations should be followed to ensure proper installation and compliance.