Pro Tips for Choosing the Right Pressure Washer

Facility managers and maintenance technicians know cleaning is a necessary evil to keep equipment working properly and facilities well maintained. For big cleaning jobs, you’ll often need the muscle of a pressure washer to get the job done quickly and with excellent results. Pressure washers come in a variety of sizes, pressures, and flows and each pressure/flow combination is made to handle a different kind of cleaning. Selecting a pressure washer that’s too small means you’ll be cleaning for hours and hours. Picking one that’s too big and you end up with damaged surfaces or uneven cleaning.

Many people don’t realize that pressure washing isn’t all about the pressure. Pressure washers have a pressure and a flow rating with the pressure measured in pounds per square inch (PSI) and flow in gallons per minute (GPM). Multiplying these two numbers gives you a measurement of the machine’s cleaning ability called the effective cleaning units (ECU or CU). Depending on who you’re talking to or what literature you’re reading, the cleaning requirements for a specific surface may be described in ECO or sometimes only PSI. As a rule, the better flow (GPM) you can get for the rated pressure (PSI), the better.

The experts have lots of good advice to help you select the right pressure washer for the job at hand. If you have a large concrete parking lot to clean, Concrete’s article Coming Clean on Power Washing suggests a “power washer with a pressure rating of at least 3000 PSI and a flow rate of at least 4 gallons per minute provides the most effective [concrete] cleaning. For faster cleaning of large flatwork areas, wheel-mounted power washers that resemble a lawn mower are available….” Looking at Goodway’s line of pressure washers, the gas powered GPW-4000-G provides 4,000 PSI, 4 GPM of cleaning power, and is wheel mounted to get around large areas. The GPW-4000-G would be the perfect fit for a big parking lot job since it provides the right amount of pressure and flow and does not need to be connected to a power source like smaller machines do. If the concrete has soaked in grease adding Goodway’s APC-100 cleaner to the hopper of the power washer can remove the grease and bring the concrete back to like new condition.

Coming Clean on Power Washing has great tips about when to use hot water instead of cold water and the various types of nozzles. Pressure washers can be put to use in a lot of different situations if you have the right accessories and nozzles. Selecting the right nozzle is important to properly focus the pressure washer’s force in the right direction. Nozzles are often classified in “degrees” like 0 degrees, 15 degrees, 40 degrees, etc. The degree is the angle at which the water leaves the nozzle. A 0 degree nozzle is a pinpoint meaning all of the water pressure is focused on one small area. A 0 degree or pinpoint nozzle is extremely powerful and should be handled with care since all of the machine’s power is behind a small pressurized jet of water. The wider nozzles are used when you don’t need quite as much power focused on one point. A 15 degree nozzle could be used for stripping paint whereas a 65 degree nozzle is for softer work like pressurized soap. A variable spray nozzle can be a good choice when you need to adjust the PSI to fit your unique task, for example this variable spray nozzle ranges from 150-1,000 PSI.  Another specialty nozzle that can add flexibility is a turbo nozzle. The unique design gives the impact force of a pinpoint nozzle, but provides the coverage of a fan nozzle. Sometimes one nozzle change just won’t do the trick, but a conversion kit might. For example, this Drain Cleaner Conversion Kit comes with a high pressure hose and 3 jetter nozzles to turn your pressure washer in to a drain cleaning tool.

Maintenance staff needing to strip paint from wood risk damaging the wood surface if the pressure washer is too powerful. A pressure of 2,500 PSI would give you enough power to blast away old paint without damaging the wood itself. The Goodway HPW-3500-G delivering 3,500 PSI gives you a little extra muscle to strip away the paint and perform even more difficult jobs. The hot water option on this pressure washer helps remove some of the stains from the wood to get it clean.

Metal buildings and steel structures rarely require significant maintenance, but annual cleanings, particularly after long, dusty, dry months are a must. A technical bulletin published by the United States Steel Corporation suggests using a high-pressure spray for cleaning dust, sap, or graffiti from metal buildings. Although the bulletin doesn’t give a specific PSI or water flow for this work, any pressure washer providing at least 3,000 PSI and 3 GPM could be used for metal building cleaning. The same power washer could be used for steel structures like parking covers or metal walkways.

Facility managers responsible for air conditioning maintenance know the importance of cleaning condenser coils to maintain proper equipment efficiency and space cooling. But condenser coils are notoriously fragile and an overzealous technician can damage the fins with a pressure washer resulting in an expensive repair. In Trane Air Conditioning’s operation and maintenance manual for its popular Voyager package unit, the manual notes in bold letters “[u]se pressurized water…ONLY, with pressure no greater than 600 PSI. Failure to do so could result in coil damage.” A powerful pressure washer like the GPW-4000-G would severely damage the condenser coils, so technicians should use a machine that delivers a lower pressure, but with strong flow. Consider Goodway’s CoilPro® CC-400HF coil cleaning system that provides 400 PSI at 3 GPM and is designed to clean coils. This machine offers lower pressure water at a high flow rate to protect the coils but still wash away dirt.

Cleaning concrete, stripping paint, removing graffiti or gum – none of these are especially pleasant tasks for maintenance staff, but cleaning is an integral part of building upkeep. Fortunately, pressure washers make easier work of these chores so long as you select the right tool for the job. Selecting the proper mix of pressure and flow and you will end up with a clean surface, no damage, and time to spare to focus on managing your buildings.

If you are in the market for a pressure washer, consider reviewing Goodway’s Industrial Pressure Washer Buying Guide. It provides even more useful information on choosing the right pressure washer for your needs.

Next Steps

  • Download our Industrial Pressure Washer Buying Guide.
  • Subscribe to our blog to stay informed about the latest HVAC news and insight.
  • Utilize our in-house experts and allow them the opportunity to assess your specific equipment and determine what cleaning method will offer you the best results.
  • Ask about our customizable capabilities including our specialized descaling formulas made specifically for different base metals and applications, including a formula for stainless steel.


  • jessica quentes

    than you foesharing this blog its very helpfulfor everyone.

    December 12, 2021
  • jessica

    It is very useful and informative post. Thanks for sharing.

    December 14, 2021

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