When designing the variable air volume system, the following principles should be complied with:
1. The speed of the fan should be adjusted, and the speed control scheme of the fan should be clarified;
It is currently considered that the most energy-saving way is to change the air supply volume of the variable air conditioning system, and it is not suitable to use a constant speed fan, and it is a simple method to change the air volume by changing the opening of the supply and return air valves. Fan speed adjustment can be achieved by voltage regulation or frequency converter adjustment, for commonly used AC motors, frequency conversion speed regulation is the most widely used method.
When designing the speed control, the parameters required to achieve the speed control should be given (e.g., CO2 concentration, duct pressure, etc.).
2. Give the minimum air volume or minimum speed limit of the fan.
At present, the commonly used fan motor is generally a coaxial cooling fan motor, when the motor rotation is reduced, the cooling capacity of the cooling fan to the motor will decrease, and too low speed will even cause the motor to fail due to poor cooling or greatly reduce its service life.