In this study, the 2-way condensation system was designed applying air-to-air heat pump to dry a marine product such as squid in the winter. And to be made the drying apparatuses by this system, there are two kinds of type, A type, was set a compressor outside of the drying apparatus, B type, was set a compressor in the drying room. And then the variations of temperature in drying room were measured to compare the heating performance of the drying apparatuses between A type and B type at $-6.5^{circ}C$, outdoor temperature. The temperature of the drying room for B type was increased to $36^{circ}C$ but the temperature of the drying room for A type was not increased to $36^{circ}C$, to be increased to $20^{circ}C$.