How do VFDs improve energy efficiency in HVAC systems?

Variable Frequency Drives (VFDs) control motor speed by varying electrical frequency and voltage, allowing fans and pumps to operate at partial loads matching actual demand rather than full speed with throttling. Since power varies with cube of speed (affinity laws), reducing speed by 20% cuts power consumption by nearly 50%. VFDs provide soft starting, reduce mechanical wear, enable better temperature control, and can achieve 30-50% energy savings in typical HVAC applications with variable loads.