Welcome to the World of Pressure Washers
There is a lot to know about pressure washers in order to get the job done correctly, quickly, without damage and on a budget. You want to know what you need, what are the smart options, how to get your money's worth, and what will help you finish up quickly and move on.
Let's walk through everything you need to know to be a pressure washing pro!
UNDERSTANDING PRESSURE WASHERS What is the difference between Power Wash and Pressure Wash?
Most people use the phrases "pressure washers" and "power washers" interchangeably. Pros know that a power washer has a heating element designed to do a much faster, cleaner job, especially for removing oil and grease. Power washers, also known as hot or hot water pressure washers, are also a great idea if working in a cold climate where the hoses may actually freeze up.
Otherwise, pressure washers and hot water or power washers are pretty much the same. They both come in wide ranges of PSI/GPM ratings, and with various accessories.
Power washers are relatively more expensive and require more maintenance, with the heating element to consider. Some pros prefer to use a regular pressure washer running chemical detergents. Others find that if usually cleaning greasy messes, the power washer pays for itself in not spending so much money on detergents. There are component heaters designed to be put inline with pressure washers, but they may not work together all that well.
PSI, GPM, PEAK PERFORMANCE, WHAT DOES IT ALL MEAN?
What Is PSI in a pressure washer?
The average home power washer consumer focuses on one number, the PSI. PSI means pounds per square inch and leads off on the signs in hardware stores.
PSI means the absolute maximum force that is coming out of your pressure washer. A stronger PSI means more cleaning power - and more risk of damage if on a delicate surface. The highest PSI always comes from a very narrow tip at close range, with lower PSI coming from wide angle tips.
What does GPM Mean on a pressure washer?
The other number that is always listed is the GPM rating, or Gallons Per Minute. In the same way that electricity is measured, both the pressure and the flow are very important.
GPM measures the total amount of water that can flow. Clearly a wide angle tip pushing a lot of water can remove dirt much faster than a low GPM flow.
Total Cleaning Power Calculation
Most people care about the overall cleaning power of. a pressure washer. Some specific power washer users may care more about the PSI or the GPM depending on the application, but who knows exactly what the future holds? As a rule of thumb, pros multiply the PSI by the GPM to get an overall cleaning power rating for the general use of a power washer. It's easy to understand. When looking over power washer models, one may have a very high PSI but a very low GPM, and another could have a very low PSI but a very high GPM. A third model that has a pretty high PSI and a pretty high GPM will have way more general cleaning power than either of the first two.
Watch out for MAX PSI versus "working" PSI
There is some hanky panky going on with some ratings on some models of pressure washers. Do not be fooled by a rating that includes a Max PSI rating AND a "working" PSI rating, sometimes known as "rated" pressure. The working PSI is all you care about. Inflated claims for max PSI can be off by as much as 30%. These manufacturers claim the max number is the amount the power washer can push out of the wand briefly, or perhaps without a tip on it at all, being used for, say, rinsing. The Better Business Bureau and others have looked into this, but they are letting it slide, since perhaps the max rating should be known as the power washer might hit that rating for a short time but long enough to damage a delicate surface.
Pressure Washer Classes - Use Enough Power for the Job
Pros know that using a too small tool will take seemingly forever to do a big job, if it is possible at all to finish, On the other hand, using a shotgun as a flyswatter is a very bad idea. Of course, you can always use a different, wider nozzle to step down from a higher PSI, and some pressure washer models can lower flow on demand. But an underpowered washer cannot be stepped up. Focusing only on the PSI, most people agree that there are general classes of appropriate pressure washers for specific tasks. Choose a power washer based on what it will be used for.
What PSI is needed for your specific task?
500 PSI or less: For delicate jobs. Should not hurt paint on cars, ok for light furniture like wicker, good to not destroy lightweight screens.
2000 PSI or less: better for grills, heavy duty outdoor furniture, tougher screens, light mildew, cleaning concrete that is not that dirty.
2000 to 3000 PSI: Good for regular concrete, heavier stains, decks, fences, siding, mold and mildew. Can power small surface cleaning attachments.
3000 to 4000 PSI: Can power larger surface cleaner attachments, and therefore clean pavement, asphalt, and heavier stains, mold, and prep for paint.
4000 PSI and over: this will drive very large cleaner attachments, tackling big jobs. Paint stripping and even graffiti removal is possible at this level.
What Power Source do you Want / Need?
In the bad old days, the only power washers available were large, gasoline powered, noisy, and you could cut off your foot with the pressure or crush one moving the washer around. Technology is marching on, and there is now a wide range of choices on how your power washer should be powered: Gas, electric, or now even battery powered are options.
Electric pressure washers have become very popular. They can be very small and lightweight, and require no maintenance, though on the flip side usually replacing them is the only way to fix them. There is a real limit to how strong they can be, maxing out around 2500 PSI, though this is going up. Electric washers are usually quiet and don't spew exhaust fumes. Mixing electricity and water is kind of scary, but most modern models come with circuit breakers built in, or they should be used on a GFCI socket.
Battery powered pressure washers are now entering the market. These can be very convenient for marine use, where you can have NO cords OR hoses if you can use lake water while cleaning boats or small docks. These washers run on power packs like modern electric drills but are not yet that strong or long lasting.
Traditionally, gasoline pressure washers are much louder, heavier, require gas, oil and maintenance, and need ventilation. But the tech here keeps getting better and better as well, Some engines like the Honda are quiet and very powerful. Gasoline is still the choice for heavy duty applications. And improving small gas engines are slowly edging into the space of electric power washers.