Here refrigerant lines are two copper lines that connect the outdoor air conditioner or heat pump to the indoor evaporator coil. The larger line typically carries a cool gas and is insulated. This is commonly referred to as the suction line, but it is also called the return line or vapor line.the low-pressure refrigerant should be insulated. With a barrier of insulation around it, the low-pressure refrigerant line shouldn't develop condensation. The foam pipe insulation will prevent the loss of thermal energy so that condensation doesn't develop. It is a common practice to hide the refrigerant pipes of mini splits in dry walls for aesthetic purposes. Apart from being more difficult to repair, concealing the refrigerant lines in walls have no impact on the performance of the mini splits. for more details download this file.
