Refrigerant pipe unit for room air-conditioner

A refrigerant pipe unit for the room air-conditioner including an indoor unit disposed inside a building and an outdoor unit disposed on the outside of the building, the building including a wall having a piping hole extending therethrough, and each of the indoor and outdoor units having two valves attached to an inlet and an outlet of each unit, said refrigerant pipe unit comprising:

• two refrigerant pipes extending through the piping hole in the building wall and interconnecting the indoor unit and the outdoor unit via the four valves attached to the inlets and outlets of the indoor and outdoor units so as to form a refrigerant passage for circulation of a refrigerant through the room air-conditioner;
• and
• a stop valve attached to at least one of opposite ends of each of said two refrigerant pipes and adapted to be closed to trap the refrigerant inside the corresponding refrigerant pipe, wherein a maximum size of said stop valve of the refrigerant pipe unit, which is measured in a radial direction about the central axis of each refrigerant pipe, is designed such that the stop valve attached to said at least one end of each refrigerant pipe can pass through the piping hole in the building wall while the other refrigerant pipe is present inside the piping hole.