<p>The exchanger has a helical tube (1) guiding a liquid heat transfer medium. The tube has a horizontal oriented aligned spiral axis (2) and helical tube parts (3, 4) provided above and below the spiral axis. The helical tube has a larger flowing cross section (5) provided for heat transfer medium and a smaller flowing cross section (6) formed smaller than an exhaust spiral coil (7). The coil has an exhaust opening (6) per spiral course in the area of the tube part (3) provided above the spiral axis. The opening connects the larger flowing cross section with the smaller flowing cross section.</p>
