By the temperature sensor TE-1, proportional-integral temperature controller TC-1, and electric control valve TV a composition of a supply air temperature control system, installed in the air supply pipe TE-1, the detected temperature signal sent to the TC-1 by TC-1 to TE a detection value of a constant comparison with the set value, while continuing to output signals to control the TV to connect a 1-degree adjustable open end, the TE-1 measured the ambient temperature maintained at set the temperature range.

    Air pressure switch DPS a 1 is used to detect the permeability of filters, filter the more dirty, lower permeability, the greater the pressure difference on both sides. When the pressure difference exceeds a set value of a DPS, the micro-switch operation, triggering an alarm.

    When the coil after the temperature is lower than a certain limit, low-temperature protection switch TS-1 to cut off the power blower, so that fresh air air valve closed, to prevent the water freezing inside the coil, coil split up.

    SW-1 for the built-in cold / warm running conversion.