How Much Powerful Pressure Washer You Need for Different Purposes
Shopping and using pressure washers can be confusing if you don’t know what you’re looking for. There are a variety of styles, designs and functionality available. It is important to first know what you intend to use it for – anything from cleaning the siding of your house to patio furniture – before you choose the amount of power you need in your pressure washer.
Some handy vocabulary to know when discussing power in regards to pressure washing:
PSI (Pounds per Square Inch) – This measures the water pressure.
GPM (Gallons Per Minute) – This measures the water flow.
CU (Cleaning Units) – This measures how fast and how well it cleans. We get this number by multiplying the PSI and GPM (PSI x GPM = CU).
Electric vs. Gas Pressure Washers
Electric pressure washers are small, portable, and capable of projects around the house (see “Light Duty” below). They have limited power due to the limited power output in the outlet of a house (this maxes out at 15A, while heavy duty pressure washers can require up to 45A). Gas pressure washers (see “Medium Duty” and up below), on the other hand, can be much more powerful in any situation, as they are only limited by the size of the engine. However, it is important to know that due to the emission of poisonous fumes, it is important to always use these pressure washers in a non-enclosed space.
A light duty pressure washer usually will be below 2000 PSI. This means it is strong enough to was your car, any grills, outdoor furniture, small decks, plastic play sets, and even patios. They have a motor powered by electricity which means they are small, lightweight, and more portable than their gas-powered cousins. These pressure washers are designed and used for home and residential use. When purchasing a light-duty pressure washer, be sure to look for a compact size, a lightweight frame, flexible hose, onboard detergent tank, and a variety of nozzles (to control the pressure of the water to a more specific amount).
Next step up are the medium-duty pressure washers, which run between 2000 PSI and 2800 PSI. They are now gas-powered and the water flow runs between 2.0 and 2.5 GPM. This can be used for all the same projects as the light-duty ones, but have several at-home projects added to the list. These pressure washers can clean large decks, siding, fences, patios, boats and vehicles. Be sure to look for a heavy-duty frame, large wheels, steel-braided or poly-braided high-pressure hoses, and a wide range of spray tips.
The heavy-duty pressure washers function between 2900 and 3300 PSI, and is also usually gas-powered. This will easily clean sidewalks, large driveways or other large concrete areas, and can clean the second-story of buildings. It can also prepare surfaces to paint.
Extra Heavy Duty (aka Professional-Duty)
These are also known as Professional Duty Pressure Washers, as they start at 3300 PSI and increase to vastly higher levels. The higher power is needed for paint prep or other industrial and manufacturing uses, such as graffiti removal, fleet maintenance, or construction-site cleaning jobs. Aim for commercial-series engine and a triplex pump, a heavy-gauge welded steel frame and a solid steel axle, some heavy-duty pneumatic tires on steel hubs, and of course, a variety of nozzles.
Multi-duty Pressure Washers
These pressure washers can switch between a high pressure (PSI), which is used for deep cleaning, or a high water flow (GPM), which improves both extended reach and washes more delicate surfaces. You can find out about all of these different types of pressure washers in our buying guide on pressure washers.