The purpose of total heat exchange is to exchange the temperature and humidity of indoor and outdoor air through the total heat exchanger, so that the temperature and humidity of fresh air entering the room can be exchanged with the indoor air, so as to reduce the impact of outdoor air on the temperature and humidity of indoor air.

The fresh air with full heat exchange is added with a full heat exchanger inside the main engine, which can quickly absorb and release heat. The discharged air and the fresh air sent into the room are cross exchanged in the full heat exchanger

Generally speaking, it is "not hot in summer" and "not cold in winter". In summer, the temperature of the air sucked in by the fresh air fan from the outdoor is much higher than that from the indoor, so the air can be released through the total heat exchanger to make the temperature of the air sucked into the indoor consistent with that of the indoor air. In winter, the responsibility is the opposite.