Feature Introduction

Unit start/stop control

The fresh air unit can automatically start/stop according to a pre-set time program, and when the fan fails, an automatic alarm signal will be sent to the central host.

sequence control

When the system starts running, the process is:

When turned on: Open the fresh air valve → Open the fresh air unit → Confirm the operation of the unit → Control the air conditioning water valve.

When closing: Close the air conditioning water valve → Stop the fresh air unit → Close the fresh air valve.

When the outdoor temperature is low in winter and the system starts operating, the process is as follows:

When turned on: Open the fresh air unit water valve → Open the fresh air valve → Open the fresh air unit → Confirm the operation of the unit → Control the air conditioning water valve.

When turned off: Stop the fresh air unit → Close the fresh air valve → Maintain a 20% opening of the air conditioning water valve.

temperature control

By automatically adjusting the two-way electric control valve installed on the return side of the water coil, the controlled temperature can be controlled. The controller will monitor the supply air temperature and compare it with the set temperature value (24 ℃ in summer and 22 ℃ in winter, which can be adjusted by the user), perform PID calculation, and then output it to the hot and cold water valves for temperature regulation. In addition, the hot and cold water valves will be interlocked with the fan status. In the absence of a fan status, the water valve will be closed tightly in summer and kept at a certain opening (20%) in winter. In this way, it not only meets the needs of energy conservation, but also provides protection for the water coil. Humidity control: The controller will monitor the humidity of the supply air and compare it with the preset humidity value (50%, which can be adjusted by the user). When the humidity exceeds the set value by 5%, the system enters dehumidification mode and automatically adjusts the opening of the cold water valve based on the deviation between the set value (set value of 55% in this working condition) and the measured value for dehumidification. The cold water valve is controlled by the greater of temperature control and humidity control requirements; When the humidity is lower than the set value of 5%, the system enters the humidification mode and automatically switches the humidification valve based on the deviation between the set value (this operating condition set value is 50 ± 5%) and the measured value for humidification.

Coil antifreeze control

Through the low-temperature protection device on the surface of the water coil, an alarm is triggered and a series of anti freezing protection actions are linked when the temperature is below the set value (5 ℃, adjustable), such as stopping the fan, closing the fresh air valve, and opening the hot water electric valve (...).

Winter summer transition control

Seasonal transition based on operating conditions.

Monitoring and alarm

1. Monitor the automatic fault alarm and manual/automatic status of the fresh air unit;

2. Filter clogging alarm, DDC

The controller will monitor the pressure difference at both ends of the filter screen. When the filter screen is clogged, the pressure difference at both ends will change and exceed the set value (400Pa, adjustable). It will display an audible and visual alarm on the operation station to remind operators to arrange relevant personnel for maintenance work;

3. Monitor the supply air temperature and automatically sound an alarm for any abnormalities;

4. During winter, monitor the anti freezing alarm signal and automatically sound an alarm for any abnormalities.

control function

1. Control the start and stop of the fresh air unit;

2. Control the switch of the fresh air valve;

3. Control the opening of the air conditioning water valve;

4. Control the transition of seasonal operating conditions.

Remote monitoring and recording