The real difference is in the volume of water that the gas one puts out. Pressure plus volume does a better job. Not that yours will not do the job it will just take longer.
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I have a pressure washer. It's a little electric Karcher. The price was right. It was given to me by a contractor who was doing some repairs required by the building inspection. He had a gas driven washer and asked if I wanted the little electric job. As I said the price was right.
Now where I live the house are all vinyl sided and subject to the weather of south Florida. Needless to sat cleaning the house is an expected chore. The first couple of years here I had the house professionally cleaned. I just used the little cleaner for the driveway, car etc. I was not happy with the job the pros did. They are in a hurry to finish and get on to the next job.
So I started out with the Karcher. It is rated at about 1500 psi. It doesn't have an extension wand so I find in a couple of spots I need to use a ladder (to reach the gable ends, for instance) It takes me a lot longer, but I am now retired and have more time than money so that is not a bad thing.
Here's the question. My washer puts out a stream at 1500 psi. I can get up close to the siding, say 10 inches or less. The pro washer puts out a stream at, let's say, 3000 psi but this spray starts out up to 18 inches away from the siding.
Since in both cases the pressure starts to fall off immediately after leaving the nozzle, what is the relative pressure at the siding in each case. /
This is not a trivial problem. My Google search only found lots of motherhood statements about what cleans better, but in the real world there are differences in applying the stream to the work surface.
Anybody out there "know" what the answer is or have a source of information about it?
Charlie
To figure the force you'd have to know the nozzle dimensions, actual pressure developed, air mix, devliery pressure, hose length/dia, water rate, etc etc etc. In ohter words, I don't think there are any easy answers to this question but it would be nice to have some ballpark numbers, not because I think they'd be very useful. If you want to do a gross ballpark, decrease the pressure by the square of the distance from the washer nozzle and you'll be approximately approximate . I'm also surprised you're able to use even a 1500 psi sprayer on a ladder; mine has enough punch behind it to actually push me around the driveway in my wheelchair when I do the driveway. A boy and his toys, I know .
HTH,
Pop
Yeah pop, lots of variables which is what got me wondering if there was any info out there. Of course the little Karcher only has a fan, no pencil setting for this toy. When I am on the ladder it is an extension ladder and my weight is holding it against the house and I am leaning forward.
To comment here on other postings that claim that the biggest factor is that amount of water delivered fails one sanity test. I can deliver the most water by simply taking the garden hose (5/8 in) and with nothing on the output side just deliver a lot of water at minimal pressure and the idea that all it takes is more water, doesn't hold water. ( I wish I hadn't said that)
What gets me going on this whole kick is the though that my little washer, because I get closer to the siding, is doing a better job that the pros who go faster but from a greater distance. Probably that is why I had been unhappy with their previous efforts.
Charlie
One of the washer guys had a formula that was something like GPM x PSI = some number. That was supposed to give you a way to compare.
It's an excellent question --w hat's the PSI or FPM at different distance. My little washer is only effective for a couple feet from the nozzle, so it's a real concern. I did get a chance to help pressure wash a house a couple days ago. Like you say, needed the ladder for the high reaches.
Wish the nozzle people could make a REAL zero degree tip, not the scatter spray they use.
Stormin Mormon wrote: Wish the nozzle people could make a REAL zero degree tip, not the scatter spray they use.
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Hi Stormie,
Actually they do make such devices. We have a so-called "turbo" attachment for one of our powerwashers. This is a true (nearly) zero degree tip which is amazingly powerful. Of course, a spray area with a 1/32" diameter is pretty useless. This wand overcomes that problem by having that tiny pinpoint spray pattern randomly and continually moving about in a somewhat tight circle. The area being cleaned by this turbo attachment is very comparable to the area being cleaned by a typical fan spray attachment, but with the turbo attachment you have an extremely high pressure pinpoint area being cleaned at any given moment.
We use this attachment rather rarely, but when we need it, then it is extremely useful. Sometimes the pinpoint spray will fail to move in its random pattern, but this is easily "fixed" by releasing the trigger and then squeezing again. That has always gotten the tip working correctly.
Try a Google search with these search terms if you are interested: powerwasher OR "power washer" turbo
Good luck, Gideon
Thanks, didn't know that. I've heard of turbo, but you did good explaining how it works. Wonder if it would work with my little 1.3 GPM unit?
Stormin Mormon wrote: Thanks, didn't know that. I've heard of turbo, but you did good explaining how it works. Wonder if it would work with my little
1.3 GPM unit?=======================
Yep. I'd guess that they are designed to increase blasting power for small units. A monster-sized power washer that can slice your leg open and send you to the hospital doesn't really need a pinpoint turbo spray.
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