Refrigerant piping
Short definitionThe suction and liquid lines between the condensing unit and the evaporator. Diameter and length affect capacity.
There are two pipes: a thin one that carries liquid refrigerant to the evaporator, and a thicker insulated one that brings the gas back to the compressor. Diameters are chosen according to capacity and the length of the run.
As the run gets longer and the number of bends goes up, pressure drop grows and capacity falls. So when choosing where the condensing unit goes, think about the pipe route at the same time. Pipe length is also a line item in the quotation.