HEAT EXCHANGER

PURPOSE:To provide a heat exchanger of less-expensive and having a comfortable energy saving characteristics by a method wherein water passages arranged on an entire surface of fins are effectively reduced and adhering water droplets are dropped downwardly. CONSTITUTION:A heat exchanger is comprised of plate fins 1 arranged in parallel to each other and heat transfer pipes 2 passed through these plate fins 1. Water passages 3 are arranged between the vertical heat transfer pipes on the plate fins 1. The heat exchanger is comprised of the plate fins 1 arranged in parallel and having louvers 6a and 6b and heat transfer pipes 2 passed through these plate fins 1 and water passages 3 are arranged between the vertical louvers 6a and 6b on the plate fins 1. As the water passages 3, stripe grooves, triangular mountain-shaped slits, arcular slits or recessed slits are arranged. With such an arrangement, water droplets adhering to the surfaces of the plate fins 1 are reduced, frosting is also reduced, an aeration resistance is reduced, a defrosting is elongated in its period and then defrosting time can be shortened.