Difference between fresh air handling unit and air conditioning unit
The air conditioner itself has a fresh air outlet, which is used to ensure the quality of indoor air and supplement indoor exhaust. The fresh air unit mainly deals with outdoor air, and the air conditioning unit is used to deal with the air treated by the fresh air fan. However, the fresh air fan can have return air and return air can also have fresh air. Its purpose is to better adjust temperature, humidity and other parameters.
Generally speaking, the fresh air unit does not bear the heat and humidity load of the air conditioning area. Its main function is to supply fresh air. Of course, the ideal state is that the temperature and humidity of the air supply are constant, so the fresh air unit generally controls the temperature and humidity of the air supply.
The electric control valve is interlocked with the fan to ensure that the air valve is closed at the same time when the power supply of the fan is cut off. The electric control valve can also realize the linkage with the fan. When the fan cuts off the power supply, close the electric control valve. The temperature control system of fresh air unit is composed of proportional integral temperature controller, temperature sensor installed in air supply pipe and electric regulating valve. The function of the controller is to transmit the supply air temperature detected by the temperature sensor placed in the supply air duct to the temperature controller for comparison with the temperature set by the controller, and according to the result of PI operation, the temperature controller sends an on / off valve signal to the electric regulating valve, so as to maintain the supply air temperature in the required range.
