How do you know if you need a gas or electric pressure washer? Do you need a machine that can handle light, medium, heavy, or extra heavy duty work? If you’re looking to rent or purchase pressure washing equipment for use at home, you should understand the basics before going into a store to purchase the machine. The first step in purchasing a pressure washing machine is to understand your budget, the cleaning projects you may have to tackle, and other tractors that come with the machine, such as: power, maintenance, or noise levels. The next step is to understand the language of water pressure, as the equipment can handle varying levels of cleaning-power.



These pressure washers are great for smaller projects. The average consumer will find these machines pack more than enough power to clean cars, grills, or boats. They will usually have less power than gas pressure washers, but will generally be less expensive and more portable as a result. These machines usually also require less maintenance than their gas counterparts, produce less noise when running (average 78 decibels), and create no exhaust emissions. These machines are usually small enough to be stored indoors without winterizing.



Gas pressure washers typically pack more power than electric machines. The gas-powered models will generally put out 2,000 to 2,800 PSI compared with 1,300 to 1,700 PSI for electric models. Gas pressure washers also produce more noise when running (up to 85 decibels). They have more weight than electric machines, and usually required pull-starting, fuel-mixing, and regular tune-ups. These machines have pumps that must be winterized with anti-freeze in colder areas since gas machines should not be stored indoors.


1. PSI, or Pounds per Square Inch

This number tells you how forceful the water will be during cleaning. The higher the PSI, the greater the cleaning power – and the greater the potential for damaging your property. Most pressure washers offer a range of PSI settings, typically from 1,300 on up to 4,000 or more. (As a point of comparison, a garden hose typically operates at 40 PSI.)

The pressure washer with the highest PSI setting isn’t always best; rather, you should choose a model that offers a range of suitable settings for the tasks you need done. For most homeowners, a high end of 2,250 PSI is sufficient. More than that and you may be wasting your money.


2. GPM, or Gallons Per Minute

GPM measures the volume of water delivered per minutes through the pressure washer. This number helps you determine how fast the pressure washer will clean and rinse away debris. At first glance, you might think a model with a lower GPM would be more efficient and thus more desirable; however, the opposite is generally true. The higher the GPM, the less time it will take to complete your pressure washing job. For example, a 4-GPM pressure washer will wash away grime in half the time of a 2-GPM model.


3. CPU, or Cleaning Power Units

To determine the cleaning power of a pressure washer, multiply the PSI X GPM. The number you are left with (called the CPU) can help you compare models to ensure that the one you’re choosing is the right fit for your pressure washing needs. CPU is also known as Effective Cleaning Units. If the CPU is high, you will have a better probability of investing in a pressure washer that is efficient and successful.

Hiring a power washing company to clean your home or commercial property can eliminate the hassle of purchasing a new washer. Professionals are experienced and trained to clean efficiently without harming your property. Contact the PWNA today to find a certified contract cleaner!


PWNA Safety Procedures

The Power Washers of North America, a group that informs members on best practices for safety in pressure washing. Make sure your technicians are ready for work, wearing appropriate clothing and operating power washers in a safe manner. Take time before each project to train our pressure washing crews on safety issues.


By Allison Hester – PWNA