Let Grainger supply durable line sets to help you ensure proper cooling unit installation. Refrigerant lines connect your outdoor air conditioner or heat pump to the indoor evaporator coil. The line set options you'll find here feature two semi-flexible copper pipes; a thicker suction line and thinner tubing called the liquid line. Find the outside diameter (OD) sizes that fit your system's specifications, and choose from 15'L, 30'L, 35'L and 50'L rolls so you can cut the refrigerant lines down to the size you need. Shop Grainger for line sets today and beat the heat tomorrow!