Pressure Washer Reviews of PSI vs GPM
If you have pressure washed before you understand the importance of GPM. But for those who will be pressure washing for the first time or for those who are buying a pressure washer for the first time, let me explain.
Most are very familiar with pressure washer PSI and how it works. The higher the number the more powerful the pressure washer. Typically the higher the PSI a pressure washer has the better.
You can always adjust the pressure down for more delicate jobs, but you can not turn the pressure higher if you need more PSI on a machine that has less PSI than you require.
On the other end of the spectrum, most do not understand pressure washer GPM (gallons per minute . GPM is far more important than PSI. Why you ask? Let me tell you.
Before we move on here is a quick note. Always store your pressure washer in a safe place like a shed. If you don’t have a shed, here is a site where you can get free shed plans to build one. You can also use stackable storage cubes to store your pressure washer accessories.
Suppose you are pressure washing your deck. Let’s say your deck is 2000 square feet and it is a beautiful sunny day (the deck is hot).
How long do you think it would take to pressure wash your deck using a 2000 PSI pressure washer that uses 1. 5 gallons of water per minute? Which is what your typical $200 pressure washer uses. Let me tell you from experience, you would be better off using a garden hose and scrubbing the mold and algae away on your hands and knees. In other words it would take a very long time.
Now lets say you have a $300 2000 PSI pressure washer that uses 3 gallons per minute. How long do you think it would take then?
Again speaking from experience, it would take about an hour. Why so much quicker you ask? Let me tell you.
Simple, GPM ( gallons per minute ). 2000 PSI is enough pressure to break lose most debris, but what happens to the debris once it is free? It needs to be washed away or gathered into a nice tidy pool of debris to be cleaned up when you are done. When you are pressure washing on a nice sunny day or any day for that matter 1. 5 GPM will produce almost no water build up, which is what you need to wash that debris away.
So the debris will be lose but it won’t go anywhere. But if you add another 1. 5 GPM to the picture that debris will wash away to wherever you want it to. It really is that simple and absolutely a must if you want your pressure washing experience to be a good one.