The way we control the speed of fan motors or pump motors has tremendously changed in the past two decades with the introduction of variable-frequency drives (VFDs), aka variable-frequency controllers ...

Variable frequency drives (VFDs), also known as variable speed drives (VSDs), are used to modulate the speed of motors in various applications, from hydronic water pumping to VAV fan units to vacuum ...

For the residents who live in rural-areas, limited water-availability is a very common problem. Therefore, many people install a water tank on the roof of the building. The water, stored in a water ...