Pressure Washers – Selection and Uses

Posted by on May 17, 2006

Pressure washers are awesome for cleaning stuff outside. Combining more power and less water usage should be enough reason for anyone cleaning things to buy one, right? Well, not really. There is always the “Do I have a use for it” argument because these are fairly substantial investments.

Pressure Washer Uses

With so much power available, what should you clean with a pressure washer? Well, my first pressure washing experience was my car. It was followed by siding on the house. You could also clean a grill, your deck, the driveway, patio furniture, or anything else where you won’t harm it with the power. The main point is it’s got to be a solid item. Don’t wash your dog with one.

Selection Criteria

There are a lot of things to consider when determining what pressure washer to purchase. The main thing to decide is between electric and gas powered. Gas powered is an excellent choice when portability is worth the premium and you will only be using it outdoors. If you want to take one with you on that weekend getaway to the cabin, for example, gas powered is probably going to be useful since you won’t really know availability of outlets ahead of time. If you’re cleaning professionally, plugging a cord into the side of a customer’s house doesn’t look professional at all. Also note that 4 cycle engines are required in California due to emissions regulations, so electric is a much more affordable choice there.

Pressure washers are also available in hot or cold models. Cold water pressure washers don’t cost nearly as much, but they also don’t do as good when cleaning really dirty or greasy areas. Pros should consider hot water, but the average home user will probably be happy with paying less and picking up a cold water model.

Pressure Washer Related Terms to Know

It’ll pay off to understand the terminology before trying to get too in-depth with comparing pressure washers. I tried to get most of the common phrases here, but feel free to drop a comment if I missed something.

Amps (A) – Electric motors typically have an amp rating to compare power between models. You can read a bit more on Amps here. Generally, higher numbers say more power in the motor.

Belt Drive – A motor with a belt drive has a belt between the pump and the spindle of the motor. The belt is a wear item and needs to be inspected regularly as it may stretch or break with age. This type of motor typically has a reduction unit (large wheel on one end of the belt, small wheel on the other) making the motor turn more or less (depending on model) to do the same work as a direct drive unit.

Cleaning Unit (CU or UCE) – This is water pressure X water flow. Higher numbers here basically means more cleaning power.

Direct Drive – A motor with a direct drive has the pump directly mounted to the spindle of the motor. This tends to have the longest life and lower power consumption for the same amount of work as a belt driven unit (higher efficiency on direct drive).

Gallons per Minute (GPM) – This is a measure of the amount of water actually consumed. High pressure with a low GPM rating isn’t as effective as the same pressure with a higher GPM rating.

Horsepower (HP) – Gas powered washers are rated in horsepower, which is just a measure of the power produced by the engine.

Nozzle – There are many types of nozzle available depending on the particular use. These are simply the tips which direct the water out of the hose. These are the simplest part, yet are the most important piece when cleaning*.

Pounds per Square Inch (PSI) – This is a measure of the water pressure. More pressure will result in quicker cleaning.

Pump – The working portion of any air compressor or pressure washer is the pump. Some industrial pressure washers even use multiple pumps. Most will at minimum have multiple plungers, and more plungers means a smoother flow of water.

* A Note on Nozzle Selection

The spray angle of most nozzles is adjustable. The wider the fan pattern, the lower the ability to cut through dirt. Zero-degree nozzles provide the most power. Fan angles of 15°-25° cover larger areas and are typically good choices for stripping and washing. Angles of 40° or more are a good choice for general washing applications. There are also nozzles known as “Rotating Nozzles” which are used for some cleaning applications as well. It’s always best to make sure you’re not using too much power for what you’re cleaning, so if in doubt start with the widest angle and narrow it if you need more power.

Availability of Parts

As with any power tool, something may eventually break. Make sure that before you spend potentially hundreds or thousands of dollars on a pressure washer you can get parts when something breaks or you misplace something. Our most popular model has historically been the Porter Cable PCE1700. It’s currently the only electric model we carry (electric is usually more popular due to lower cost), although we have a gas powered model at the same price. As with most any Porter Cable tool, we have the parts available on Tool Parts Direct. Many inexpensive pressure washers make parts tough to find, so sticking with a known brand is typically a good idea.

6 Responses to Pressure Washers – Selection and Uses

  1. Anonymous

    Looking for instructions on how to rebuild water pump for Karcher 2500 G pressure washer. Can you refer to a blog site or other?

  2. Brian Mark

    You could try PressureParts.com (another Omaha, NE based business.) He’s got most of the parts lists available. I don’t know of any sites that describe rebuilding one, though.

  3. Anonymous

    do you have any suggestions for which pressure washer I should purchase for using outside in my backyard (cleaning the shed, my dog’s kennel floor which is cement, the deck, etc)?

  4. StihlPressureFan

    Thanks for the info!

    This helps out alot!

  5. Alice

    I love my Karcher electric pressure washer. It gives me plenty of washing power for most things without worrying about destroying the item. Although it tear up some rotting wood on an old deck pretty nicely!

    I think that unless you really need lots of power on a regular basis (like you do this for a living), most homeowners can do just fine with an electric model. But guys always like to have “MORE POWER”!!

  6. Alex

    I need a pressure washer but I don't know what the type is called so I can't find it on Google.

    It will be a permanently mounted overhead "tube" with multiple nozzles to clean objects about 100 inches wide as they slide underneath it on a conveyor belt.

    An alternative, the kind of undercarriage pressure washing system that trucks at mining camps drive over would work.

    Anybody know what these are called?