Abstract: A line set box, and a method of use thereof, comprising a generally rigid conduit box panel having a removable front cover, wherein the box panel has knockouts and insertable sealing grommets enabling sealed passage of conduits from inside a structure to outside the structure. Thus, the conduit box functions to house and protect end portions of refrigerant lines, drain lines, and/or control lines of an air-conditioning system during construction of a building until the refrigerant lines and the control lines are connected to a compressor of the air-conditioning system located outside the building.