How VFDs are Improving the Efficiency and Performance of HVAC Systems

by Chen Yajun Executive

HVAC systems have become a key component today, as you can witness an air conditioner in your home to large HVAC systems being deployed in industrial plants. As these are used for the operation of cooling and heating system, they must perform at the optimal level to deliver efficiency and durability.

Combining HVAC systems with variable frequency drives results in the implementation energy saving platform that helps energy savings up to 50 percent over the traditional applications. With advanced HVAC systems being developed today, it has become practically easy and convenient to install VFDs in any type of HVAC system.

How VFDs improve the overall performance and efficiency of HVAC systems?

HVAC systems are basically used for operating pumps and fans at a constant speed. The conventional motors tend to operate at constant full speeds irrespective of the cooling or heating load. This issue has been effectively resolved using VFDs:

• Building HVAC systems continue to use more energy throughout the time while the peak load condition occurs only for 1 to 5 percent of operating hours. VFDs ensure that the operating speed is at less than the full load, thus reducing energy consumption.

• Traditional systems used to be oversized in design because they were designed for peak load, capable of handling unexpected loads. Using VFDs ensure space saving and elimination of oversized HVAC system design.

• VFDs work efficiently in handling the speed of the induction motors (used in HVAC systems), which allows for higher ratio of energy saving. For example, if the speed is lowered one-fourth, then the reduction in energy usage is up to half.

VFD Benefits to the System

• The most common and most significant benefit of using VFD is energy saving. Industries across the globe and building systems have befitted capably using the VFDs in the motors.

• Another specific benefit VFD ensures is reduced wear and tear. The induction motor, during the start time, powers by drawing current that is many times higher than the normal operation time frame resulting in increased strain and heating. VFD limits the inrush of the current during the motor start time applying low voltage and frequency, which helps enhancing the overall life of the motor.

• VFDs also ensure better and precise control of application, like adjusting the flow rate to maintain ample pressure levels.

All the above factors have helped VFDs not only improving the life, performance and energy efficiency in HVAC systems but across several other system applications in the industries. The manufacturers for frequency high performance drive in China, or elsewhere, are constantly evolving the technology ensuring we are going to see more optimised and high-end VFDs that will make industrial applications more powerful, efficient augmented.