It is crucial on which surfaces and for which cleaning jobs a high-pressure cleaner is used. While some paving stones refuse to let go of dirt even at high pressure, the same pressure can easily dent car body panels and gutters. Ideally, the device can be infinitely adjusted.
The decisive criterion is the maximum working pressure
There is no such thing as the ideal pressure for a high-pressure cleaner. In order to be able to use it as flexibly as possible in private households, it should be as infinitely variable as possible. More imprecise, but in many cases sufficient, the incident pressure can be influenced by changing the distance. However, as the distance increases, the increasing “dusting” of the water can noticeably reduce the cleaning effect.
In this sense, the maximum output in bar is the decisive criterion when buying. It should be noted that the rated power of the pump does not correspond to the actual working pressure reached at the end of the nozzle. The maximum output should be geared to the most demanding cleaning jobs. As a rule of thumb, 15 to twenty percent difference can be calculated.
If external surfaces are to be cleaned, at least 150 bar working pressure is recommended, which corresponds approximately to the maximum pressure of 170 to 180 bar. Depending on the type of soiling, a high-pressure cleaner with hot water and heating function can also achieve satisfactory results with lower pressure.
|Application/dirt type||recommended pressure/bar|
|Bicycle freshly soiled||20|
|Garden furniture plastic||50|
|Wooden garden furniture||80|
|Hard natural stone||100-150*|
|Asphalt||up to 300|
*Natural stone can react very sensitively, always increase carefully and observe.
**A hot-water high-pressure cleaner gets by with about 100 bar.
Minimum flow rates must be suitable
Another aspect for the cleaning effect is the water flow rate of the device. Pressure washers tend to have too low a delivery rate in relation to the pressure. This can be compared to a car with too little engine power: It drives, but …
At the following pressure values, these minimum flow rates in litres per hour are recommended:
- At 100 bar 360 litres per hour (l/h)
- At 120 bar 380 l/h
- At 150 bar 420 l/h
- At 180 bar 480 l/h
There are accessories such as dirt cutters that do not have to rely on pressure alone, but help mechanically.