What does PSI mean in pressure washers? Whenever you investigate pressure washers and you will quickly find yourself encountering acronyms. A common example of these acronyms are PSI. It is quite easy to spell out what the letters stand for – Pounds per Square Inch, but what do they mean in practice? Fortunately, you don’t need a degree in engineering to understand it means.
So What does PSI (Pounds Per Square Inch) Mean
Despite their many similarities pressure cleaners differ, unsurprisingly, in one key area: the pressure they provide. Pressure is ranked in PSI (pounds per square inch) in English units or NPM (newtons per square meter, also known as pascals or bar). Let us stick with the English units since they’re more familiar to most readers and the manufacturers more often rate their products this way.
A pound is technically a simple measure of weight – typically the amount a given mass ‘pushes’ under the influence of gravity. More generally, it’s just a measure of a force. When that force – water pushing through a hose, in this case – acts on or through a certain area it’s possible to form a new unit: pressure, the force per unit area. That’s the technical definition of pressure, how hard something is pushing against how big a flat space. A smaller area can produce a higher pressure with the same amount of force. It’s essentially the reason that hose nozzle diameters are so small.
Well, greater pressure provides both more cleansing power and lets you reach higher heights with the stream. A gas-powered, 3,000 PSI pressure washer will, all other things being equal, let you get up to those high eaves on a two-story house. The electric model that provides, say, only 1,500 PSI may not reach.
So, How Much Pressure is Enough?
There’s no straight answer to this question. It depends on what you want to clean – how durable the material is and how you use the pressure washer. Even a relatively modest-strength pressure washer – say 2,500 PSI — could put a hole in soft wood if you move the nozzle close enough. To give you some rough guidelines for real-world use, consider what you plan to wash with your pressure cleaner most often.
A pressure cleaner that generates 1,500-2,000 PSI can be useful for cleaning wooden fences, patio furniture, the car, and other relatively easy cleaning jobs. On the other hand, you might require a high-powered gasoline model – one that can deliver, say 3,100 PSI – for the tougher scenarios. Such things as cleaning oil slicks off the garage floor, blasting accumulated mud from rain gutters on the second story, and the like often require substantial pressure.
I hope this article has helped you understand what PSI means.