Many homeowners and business owners choose to rent or purchase their own pressure washing equipment instead of contracting with a power washing company for cleaning services. However, in order to choose the best pressure washer for the job – and to use it effectively – it’s important to understand the three primary pressure washer ratings: PSI, GPM and CPU.
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 1,500 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 how much water a pressure washer uses during each minute of pressure washing. 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.
Ultimately, a higher GPM can potentially save you both time and money (on fuel or electricity to power your pressure washer).
3. CPU, OR CLEANING POWER UNITS
Multiplying PSI by GPM gives you the CPU, also known as Effective Cleaning Units. Calculating CPU is a handy way to compare pressure washing models at a glance. If the CPU is high, you will have a better probability of investing in a pressure washer that is efficient and successful.
Of course, hiring a power washing company to clean your home or commercial property will eliminate the hassle of purchasing a new washer. Plus, professionals are experienced and are trained to clean efficiently without harming your property. However, if you’d rather do the job yourself, understanding PSI, GPM and CPU is a good place to start.