To moderate increase of pressure loss and degradation of heat transferring performance due to frost formation.
This fin tube heat exchanger 1 has a plurality of heat transfer fins 31, 32, and a plurality of heat transfer tubes 21, 22 penetrating through the plurality of fins 31, 32. The plurality of heat transfer fins 31, 32 include a plurality of first fins 31 disposed at an upstream side in the airflow direction, and a plurality of second fins 32 disposed at a downstream side with respect to the plurality of first fins 31 so that the air passing through the plurality of first fins 31 flows therein. The first fins 31 are provided with blade-shaped auxiliary fin sections 11 formed by cutting and raising a part of the first fins 31 respectively on a tube near-field region 35 at an upstream side with respect to an upstream end P1 of the first heat transfer tube 21, and a tube near-field region 35 at a downstream side with respect to a downstream end P2 of the first heat transfer tube 21. A curved line 11b of a basic end of the auxiliary fin section 11 is in parallel with the airflow direction.
HONMA MASAYA
AOKI AKIRA
