VFDs are most suited to variable torque loads, such as fans and pumps, which are frequently operated at part load. As a result, the system’s total energy efficiency improves. This demand would normally only occur for a few hours each year, therefore the system would be large and inefficient for the rest of the year.īecause the VFD can run the system at greater than rated speeds, the entire system may be sized for more common situations, while the system can be over-speeded to meet exceptional demand conditions. The motor operates slowly during low demand, and the power consumption falls in proportion to the demand, resulting in enhanced efficiency and energy savings.įurthermore, because the fan operates at a constant speed, it must be designed to handle the highest potential demand. The output of the system is regulated by altering the motor’s speed or torque directly with a VFD. In either case, energy is squandered by reducing the flow of air, and the system’s efficiency is lowered. In the case of an HVAC fan, if the air supply-demand ratio falls but the energy input from the fan stays constant, the energy in the flow must be dissipated through vents or valves, or the air must be redirected and discharged elsewhere to limit the supply of air to the conditioned room. Photo Credit: The fixed AC motor speed and torque imply that the equipment these motors drive functions at a constant speed and torque as well, and system management is done by dissipating energy through mechanical methods in the absence of variable frequency drives (VFD).
This offers extra benefits in terms of energy savings, but it should be done with prudence. Continuing with the HVAC fan example, if the demand on the HVAC system changes, the VFD-controlled motor may adjust the fan’s speed to reflect the change in demand.įor brief periods of time, a VFD can also be utilized to drive machines at greater than rated speeds. This allows the motor speed and torque to be precisely changed to meet the load/demand it is servicing. The incoming power supply is intercepted by the VFD, which adjusts the incoming voltage and AC frequency dependent on the load requirements. When this is used to power an HVAC fan, for example, the fan will run at a consistent speed and torque. Because most energy supplies have a defined frequency and voltage, induction motors linked directly to a typical power source will have a consistent speed and torque. The frequency and voltage of an AC induction motor’s power source determine its speed and torque. How Does V ariable Frequency Drive (VFD) Work? VFD gives the flexibility to adapt the fluctuating load profile of the cooling system, allowing for great system efficiency even at partial loads. Instead, they generally function in a light load mode.
#WILL DROP POWER CONSUMPTION FULL#
While data center cooling systems are designed to manage peak loads in the most extreme circumstances from summer heat to component failures – they seldom, if ever, function at their full capacity. Because of the link between motor speed and energy consumption, even a slight decrease in speed can result in a considerable increase in energy efficiency. This is in contrast to operating the engine at full speed and throttling and dampening the output. Drives allow the speed of electric motors used in cooling applications to be accurately regulated, ensuring that the needed flow is produced at all times, resulting in energy savings of up to 35%. The variable frequency drive (VFD) has been shown to be a very efficient energy-saving cooling technology. Adopting VFD and energy-efficient motors for cooling systems is one method that can help reduce PUE significantly. To further reduce PUE, steps must be taken to improve data center efficiency during their operational life as well as to adopt cutting-edge technology in new projects. The PUE levels of data centers have been falling over the years, from roughly 2.6 in 2006 to 1.7 in 2019, according to research conducted by the Uptime Institute, albeit the recent trend, after 2013, has been flat.
#WILL DROP POWER CONSUMPTION FREE#
In an ideal world, a data center’s PUE would be 1.0, which would mean its cooling costs are zero with 100% free cooling. Power use effectiveness (PUE) is a ratio that is calculated by dividing the total power entering the data center by the power consumed by its IT equipment.
Green Grid, an industry alliance, developed one of the most widely used energy efficiency indicators. Vaccine Transport and Storage Monitoring.