All posts by alanlachapelle


Many people make the mistake of confusing a Kilowatt (a unit of power) and a Kilowatt-hour (A unit of energy). The same could be said about Watts and Watt-hours, but the Kilowatt is much more commonly applied.

A kilowatt is power. Think of it as a rate of consumption. This is how fast you are gobbling up electrons from the grid.

A kilowatt-hour is energy. This represents the amount of electrons you have gobbled from the grid since your last utility bill, for example. (not really electrons, but you get the picture) Continue reading Kilawhat?


VFDs Spend a little Save a LOT

So one of the big things I have been pushing for in my job has been VFDs on every motor >2 horsepower. VFDs can be incredibly useful tools. First of all, without considering energy implications, they give you finite control of the motor. Just being able to modulate capacity is huge, especially if you have a control system that can handle the input.

Energy savings, however, are really where its at. Most of our motors in the data center are connected to a fan or a pump. For the most part, fans and pumps are variable torque loads and (with the exception of some oddball positive displacement pumps) vary their consumption with the cube of the speed, per the fan laws. Continue reading VFDs Spend a little Save a LOT