Abstract: An order menu that includes a plurality of specifications in respective functional blocks, into which a customized product is divided into, is provided from a factory through Internet. A customer selects a required specification from the order menu to determine the customized product. Based on data input through the order menu, material arrangement and directions for production can be dealt with on line, and data on the customized product are shared between the customer and a manufacturer.

Abstract: A heat source unit and refrigerant used in an existing refrigeration system are replaced with new refrigerant and a new heat source unit which employs the new refrigerant and is equipped with an oil separator and extraneous-matter trapping device. An indoor unit of the existing refrigeration system may be used, in its present form, or replaced with a new indoor unit. Further, connecting pipes used for the existing refrigeration are reused. After replacement of refrigerant, the refrigeration system performs an ordinary operation after having performed a cleaning operation. The extraneous-matter trapping device is provided in a refrigerant pipe close to the heat source unit or in a bypass channel connected to the refrigerant pipe close to the heat source unit. Alternatively, only the heat source unit of the existing refrigeration system is replaced with a new one, and there is employed refrigeration oil which has no mutual solubility with respect to HFC or has very low mutual solubility.

Abstract: A heat source unit and refrigerant used in an existing refrigeration system are replaced with new refrigerant and a new heat source unit which employs the new refrigerant and is equipped with an oil separator and extraneous-matter trapping means. An indoor unit of the existing refrigeration system may be used, in its present form, or replaced with a new indoor unit. Further, connecting pipes used for the existing refrigeration are reused. After replacement of refrigerant, the refrigeration system performs an ordinary operation after having performed a cleaning operation. The extraneous-matter trapping means is provided in a refrigerant pipe close to the heat source unit or in a bypass channel connected to the refrigerant pipe close to the heat source unit. Alternatively, only the heat source unit of the existing refrigeration system is replaced with a new one, and there is employed refrigeration oil which has no mutual solubility with respect to HFC or has very low mutual solubility.

Abstract: An order menu that includes a plurality of specifications in respective functional blocks, into which a customized product is divided into, is provided from a factory through Internet. A customer selects a required specification from the order menu to determine the customized product. Based on data input through the order menu, material arrangement and directions for production can be dealt with on line, and data on the customized product are shared between the customer and a manufacturer.

Abstract: An air conditioning system of the present invention has a refrigerant circuit including a compressor, an oil separator, a condenser, a expansion device, an evaporator, a first accumulator, and a second accumulator which are connected in order by piping, said evaporator, said first accumulator, said second accumulator, and said compressor being connected in series; a first oil return bypass for connecting said oil separator and a connection pipe between said first and second accumulators; and a second oil return bypass for connecting said first accumulator and a connection pipe between said second accumulator and said compressor.