Pressure Washer balance of Power, Pressure & Volume for Washbays

Creating a balance between Power, Pressure and Volume is important when choosing a Pressure Washer. Too much of one can result in a poor cleaning performance. But what should this balance be?

Due to its name - Pressure Washer - it is often wrongly assumed that a higher pressure value means a better cleaning performance. However, this is only one factor that contributes to the performance.



Power, Pressure & Volume & Getting the Perfect Balance

Power, Pressure and Volume are the three main factors you should consider when choosing a Pressure Washer. The achievement of Pressure and Flow is only possible with the availability of adequate Power.

When 3 phase 415Volt power is available, then achieving the required pressure and flow is not a worry.

However, when power is restricted to 1 phase 240 Volt, it is essential to understand the balance between pressure and flow to achieve the best performance from your Pressure Washer for your requirements without exceeding the available power.

To understand the significance Flow is when choosing an Industrial Pressure Washer, imagine you have been instructed to sweep a large workshop floor with a typical 15" wide sweeping brush. Imagine then you are offered a wider 30" brush.

If the width of the brush was the equivalent to Water Flow Rate, you begin to understand how the increased brush width or flow rate makes a rather significant difference to the time and effort required to complete the job.

Visit Pressure Washer History for a brief background of Pressure Washers.


A farmer came to us after helping to Pressure Wash a barn. He had used a 240 Volt Rhinowash Cold 12 Pressure Washer. This machine would operate at a pressure of 83 bar (1200 psi) with a flow of 13 litres per minute (2.8 gallons per minute).

He asked us: Why was it that he had been able to clean one half of the barn on his own in the same time that it took two other farmers to clean the other side - even though they were using 100 bar (1500 psi) Pressure Washers?

Was it because the farmer was working harder than the other two farmers? NO!

The reason was that although the other farmer's machines were producing a higher pressure, the flow rate was less at only 11 litres per minute (2.4 gallons per minute) to stay within the power limits of 240 volt supply.

If we compare this to our earlier example of sweeping, the farmers with the higher pressure would be the equivalent of sweeping with the 15" wide brush.

However, the farmer with the Rhinowash machine working at a lower pressure but higher flow would be the equivalent of sweeping with the 30" wide brush.

Although the Rhinowash farmer had 300 psi less, he had an additional 3 lpm of flow.

This illustrates why you shouldn't focus on the pressure alone. Instead find the equipment and performance most suited to your cleaning requirements.

Still unsure? Call us on 0845 643 1199 and we can assist you make the right choice for your needs!