What is the first thing you think about when you hear the word horsepower? A powerboat? A car? A motor?
Makes sense, horsepower is a measure of what a motor can do and how fast it can do it. Take a car, for example, the higher the horsepower, the faster the car can go.
So where did the term come from, then? According to LiveScience the term was first coined in the late 1700s by James Watt. Looking for a way to advertise his steam engines, he invented a unit of measurement that would effectively showcase the superiority of his steam engines compared with something people were familiar with; horses.
But instead of figuring out exactly how much power a horse really produced, he estimated. Watt guessed that a pony could lift and average of 220 lbf (pound-force) 100 ft. per minute (220 lbf x 100ft./min. = 22,000 lbf x ft./min.). From there, he extrapolated that a horse could lift 50 percent more than a pony, bringing the estimated power of a horse, or horsepower, to 33,000 lbf x ft./min.
One would assume based on the term that a horse could produce 1 horsepower. Actually, the maximum output of a horse is closer to 15 horsepower.
Using the car analogy, it is easy to think that the higher the horsepower air compressor the better for your application, but that is not always the case. It is important to make sure the rated horsepower matches your application; generating too much air can be just as detrimental to your system as not producing enough and choosing the wrong air compressor for your facility can lead to problems with production and increase costs due to wasted energy.
A motor in an air compressors job is simply to drive the cylinders that compress air. This is a complex process. As a result, the amount of horsepower a motor has and the amount of work a compressor can do is not always straightforward. If a 5 HP air compressor and a 10 HP air compressor can both produce the amount of compressed air needed for the job, the 5 HP model is working more efficiently, saving you money on fuel without a loss in performance. In this case, the 5HP model is the proper air compressor for the application. On the other hand, a 5HP compressor cannot do the same job as a 100HP compressor. That is why it is so important to make sure you get the correct HP compressor.