CLAIMS [Claim 1]
A refrigeration cycle apparatus using a flammable refrigerant, the refrigeration cycle apparatus comprising:
an outdoor unit including at least a compressor and an outdoor pipe;
an indoor unit including at least an indoor heat exchanger and an indoor pipe;
an extension pipe connecting the outdoor pipe and the indoor pipe to each other;
a pipe connection chamber disposed in a casing constituting the indoor unit and housing a connection portion connecting the indoor pipe and the extension pipe; and
a pipe draw-out chamber disposed in the casing constituting the indoor unit, the extension pipe drawn out from the pipe connection chamber passing through the pipe draw-out chamber,
the pipe connection chamber and the pipe draw-out chamber being partitioned from each other by a partition having a through hole, the extension pipe penetrating the through hole,
a part of the pipe draw-out chamber being constituted by a part of the casing constituting the indoor unit, the extension pipe penetrating a through hole formed in the part of the casing. [Claim 2]
The refrigeration cycle apparatus of claim 1, wherein
the pipe draw-out chamber is divided into a plurality of chambers by one or more additional partitions each having a through hole, the extension pipe penetrating the through hole, and
the extension pipe seriaily and sequentially passes through the chambers of the pipe draw-out chamber. [Claim 3]
The refrigeration cycle apparatus of claim 1, wherein

the through hole in the pipe draw-out chamber is located in an upper portion or
a top panel of the casing, the extension pipe penetrating the through hole in the pipe
draw-out chamber.
[Claim 4]
The refrigeration cycle apparatus of any one of claims 1 to 3, wherein
the indoor heat exchanger includes a plurality of heat radiation plates spaced
from one another, and a heat transmission pipe penetrating the plurality of heat
radiation plates in a serpentine manner, and
the pipe connection chamber houses a joint portion jointing the heat
transmission pipe and the indoor pipe.
[Claim 5]
The refrigeration cycle apparatus of any one of claims 1 to 3, wherein
the indoor heat exchanger includes a refrigerant channel and a water channel
adjacent to each other, and a refrigerant connection portion communicating with the
refrigerant channel, and
the pipe connection chamber houses the refrigerant connection portion.
[Claim 6]
The refrigeration cycle apparatus of any one of claims 1 to 5, wherein the indoor pipe and the extension pipe are connected to each other by a
mechanical joint.
[Claim 7]
The refrigeration cycle apparatus of any one of claims 1 to 6, wherein
a gap between an outer periphery of the extension pipe and an inner periphery
of the through hole is filled with a gap filler of a closed cell foam material.
[Claim 8]
The refrigeration cycle apparatus of any one of claims 1 to 7, wherein the refrigerant is one of a single component HFC refrigerant of R32 (CH2F2: difluoromethane), HFO-1234yf (CF3CF^CH2: tetrafluoropropene), orHFO-1234ze (CF3-CH=CHF), or a mixed refrigerant of these single component refrigerants.