Performance Tests
No matter how you look at it, facts speak for themselves.
Below are the results of some key measurements and simple tests performed on the Dirtworker and Nomad 18 volt cordless washers, compared with our competitors.
The Dirtworker outperforms all the competition, and the new 18V Nomad opens up new possibilities for those who would like even more cleaning power and cordless cleaning.
Pressure
First up, ignore claims of 'up to' or 'between x and y' pressure, because these are meaningless. What they relate to is the operating range of the internal pressure switch that turns the pump on and off at high speed - not the pressure that comes out of the spray gun; the pumps continuously switch on and off in order to keep the water in the hose pressurised.
What matter are the pattern and the effectiveness of the water leaving the nozzle. Water pressure and great spray gun nozzle design are what make the difference.
How pressure is measured
The British Standard for measuring the pressure in pressure washers is to take one measurement in the hose when the product is operating. So in our tests this is what was done.
All the variable nozzles on the spray guns were set to the mid-setting, as this is the optimum spray pattern for cleaning.
Then, measurements of the average pressure in the hoses were taken in the hose line 20cms from the pump.
| Product | Actual Pressure (PSI) |
| 18V Nomad | 98 |
| Dirtworker | 77 |
| Competitor A | 55 |
| Competitor B | 50 |
| Competitor C | 51 |
| Comparison of internal hose pressure at the mid-setting of spray gun trigger patterns. | |
Notes: (1)The same gauge was used for all testing. As the pressure in the hose oscillated at high speed and produced a high speed "flutter" on the gauge needle, the average reading was recorded. (2) Battery powered products were tested when fully charged. (3) Autocorded products were powered by a highly regulated 30Amp laboratory power supply unit. (4) All tanks were full of water with caps in place.
The table clearly shows that the new 18V Nomad cordless produces almost twice the pressure of the competition on this setting, followed by the Dirtworker with almost half as much again as the nearest competitor. None of the washers produced 130PSI claimed by our competitors - not even our products.
Water Flow
The water flow of each washer was measured. This is a good indicator, but not an assurance, of cleaning effectiveness.
Once again, the 18V Nomad cordless heads the table, followed by the Dirtworker. However, competitor C pumps out 30% more water.
| Product | Actual Flow Rate in Litres/Min |
| 18V Nomad | 2.15 |
| Dirtworker | 1.9 |
| Competitor A | 1.8 |
| Competitor B | 1.58 |
| Competitor C | 2.8 |
| Comparison of flow rates at the mid-setting of spray gun trigger patterns. | |
Notes: the measuring vessel was uncalibrated and used to establish a comparison. All products were run for a timed one minute duration and the volume of water exiting the spray gun was measured.
The above shows the need for a balance between having enough 'oomph' to clean effectively and enough time to do it; you'd don't want the water to flow too slowly either. You just want to get the job done optimally.
Cleaning Force Deflection Test
This test measures the amount of cleaning force or 'oomph' that comes out of the spray gun - the actual work done that customers are interested in. This is the product of 1) the operating pressure and 2) the design of the spray gun and nozzle.
- To do this a test rig was set up consisting of a freely swinging plate hanging vertically down, on which a target was marked.
- Each washer was then set up using the same mid-setting used in the tests above.
- Maintaining a constant distance, all spray guns were aimed directly at the target on the plate and rotated to maintain the jet of water perpendicular to the plate - this ensured that all the force of water is being used to defect the plate and not just skimming off at an angle and being wasted.
- Measurement of the angle in degrees of deflection from vertical of the plate was recorded.
- A measurement of the force required to deflect the plate by the number of degrees recorded for each product was calculated.
The table below shows those results.
| Product | Force shown in Newtons (N) |
| 18V Nomad | 1.36 |
| Dirtworker | 1.11 |
| Competitor A | 0.80 |
| Competitor B | 0.69 |
| Competitor C | 0.91 |
| Comparison of Newtons of force the water exerted on the target at the mid-setting of spray gun trigger patterns. | |
The Nomad Cordless produces 70% more force than competitor A, 97% more than competitor B, (yes, twice as much) and 50% more than competitor C.
The Dirtworker produces 40% more force than competitor A, 60% and 21% more than competitors B and C.
(The spray guns were also tested when adjusted to create a solid stream, the setting most expect to be the most powerful. The 18V Nomad with its greater control of spray patterns produced even more force while all other products exhibited minimal change from the mid-setting.)
Battery Life
The Nomad Cordless and its battery powered competitor were run constantly from fully charged to when they effectively became unusuable, on the same spray setting as all the tests.
The same in-hose pressure measurements and force calculations were taken every minute over the time of effective cleaning power. The data was plotted and analysed.
It took 26 minutes of continuous spraying for the 18V Nomad to fall to the starting level of force of its competitor!
The competitor's battery lasted 6 minutes longer than the Nomad before it fell to a level where the pump pressure started to tail off.
Tank Capacity
The water capacity of our competitors' products was measured. This is real world with the tanks standing on level ground and filled to the point it starts to trickle out of the filler neck. This is what was found:
| Product | Actual |
| Competitor A | 1.6 litres less than claimed |
| Competitor B | 1.2 litres less than claimed |
| Competitor C | 4 litres more than claimed. We don't mind being fair. |
Noise
We didn't even need an uncalibrated sound pressure level meter to measure this.
The product that claims to be extremely quiet in operation is in fact the noisiest! The Dirtworker is the quietest. In fact it's virtually silent.