| 摘要 |
PURPOSE:To prevent occurrence of clogging of a heat exchanger due to freezing by providing an air supply temperature adjusting means by which a part of exhaust before heat exchanged by the heat exchanger is bypassed and mixed into air supply before heat exchanged by the heat exchanger so as to adjust temperature of the air supply. CONSTITUTION:In order that for ventilation of heat exchanging, temperature of air supply K is adjusted by an air supply temperature adjusting means 5, a first damper 52 is half-opened as shown by a double-dotted line in Fig. 2 and a second damper 53 is set as shown by a one-dotted line in Fig. 1. Then, as shown by an arrow of a double-dotted line, a part of exhaust H before heat exchanged flowing through an exhaust passage 12 is taken into a bypass passage 51, and mixed in the air supply K before heat exchanged flowing through a supplied air passage 11 without passing through a heat exchanger 2. By this, the temperature of the air supply can be raised, whereby dew condensation and freezing in the heat exchanger 2 can be prevented. |
