The main functions of HVAC, a household central air conditioner, include: heating, ventilation and air conditioning. The most important feature of central air conditioners is the creation of a comfortable indoor air environment, with the fan playing a vital role in an air conditioning system.
The advantages of using Dunli external rotor fans for HVAC:
1. Compact structural design; 
2. Whole-fan dynamic balanced, stable operation, low noise, small vibration, high reliability; 
3. High efficiency, low power consumption;
4. Tapped speed regulation (AC) and stepless speed regulation (EC);
5. Rear guide vanes available for installation, to further improve  aerodynamic efficiency and flow range of the fan;
6. Different blade materials, including cast aluminum, plastic, steel plate, etc., for varied environmental application requirements.