제 1 열교환부(30) 및 제 2 열교환부(40)는 전후방향으로 중첩되되, 접촉되지 않고 소정거리 이격된다.
The first heat exchange part 30 and the second heat exchange part 40 are overlapped in the front and rear direction, but are not in contact and separated by a predetermined distance.