As a Supplier into the industry, I watch and read with interest the eternal debate between WFP and Trad users as to which method is best. Both, of course, have their place and many use a combination. Interestingly what we now refer to as Traditional cleaning has changed dramatically over the years. In 1936, Ettore Stecconne developed one of the 1st T-shaped tools with a single piece of rubber to dry windows streak free. In 1936, he patented what he called the New Deal and began manufacture and sales from his home.
He approached J Racenstein with the product and initially knocked back, So he made a bet with the then owners that within one month they would be begging to stock the product.
He simply provided every cleaner in New York with one and ask them to try it for a day, Needless to say, Ettore won his bet. (source http://www.ettore.com ) The squeegee continues to be developed to this day.
Some view WFP as a modern fad. It may be surprising that the 1st patent for a brush on a pole to clean windows was applied for in 1895 by the window cleaners A. Thierry and H.F Schoenfield.
In 1957 Tucker produced their 1st aluminium water fed pole, Again the pace of development and types of poles continues with new innovations such as Carbon, fibre glass and composite poles getting ever lighter and stronger.
In summary, you could say there is no such thing as Traditional window cleaning methods as innovation and development will continue to improve and refine the processes.
What is not in doubt is that the window cleaner is a professional providing an often overlooked professional service.
The days of a chap on a bike with a bucket and dirty rag are long gone, Yet this false perception still exists in the mind of the public.
For me Educating your customers is key, You have public liability insurance, HSE training, Risk assessments, VAT and investments in tools and equipment.
Whatever method you use never loose sight of the fact you are professionals.
Working at height regulations 2005 in the UK are often quoted as the main reason as to why WFP has enjoyed huge success. HSE figures quote and record work-related falls, A large number of these are falls from ladders. This does, of course, include many different types of work and sites. Yet if you look at the regulations nowhere does it mention that ladder use is banned or prohibited above a certain height.
We all know of people who fall less than 4 feet with fatal consequences and yet people can fall much further and survive. In 2010, the World health organisation estimated 540,000 people died from falls globally. So just how high is too high and from what height will a fall either lead to permanent disability or worse.
The general consensus is if you're working above 6 feet that additional practical safety measures should be considered.
The regulations state
- Before working at height you must work through these simple steps:
- avoid work at height where it is reasonably practicable to do so;
- where work at height cannot be avoided, prevent falls using either an existing
- place of work that is already safe or the right type of equipment;
- minimise the distance and consequences of a fall, by using the right type of
- equipment where the risk cannot be eliminated.
So in effect then if you want to use a ladder to clean 30 to 40 feet in the air you can BUT have you considered a safer way of accomplishing the same job without ever leaving the ground.
What other drivers for WFP exist?
There are many factors which have driven the success of WFP. Each market will have its own drivers as does each individual business professional. These would require an article of their own. Let us look at some, commonly in the UK and Europe, a window cleaner will carry to site all the tools and materials required for the job including the water.
There is a practical limit to how much water can be carried due to space and weight considerations. This, in turn, means that a limited resource is managed to ensure that the planned days work can be carried out.
In The US in some cases, use of the customers supply may be an option, by connecting to an external tap in both domestic and commercial cleaning applications. Rather than producing pure water and transporting to site. Many will use an on demand RO/DI production cart.
A downside of this method is a lack of mains water pressure to ensure the RO membrane is working efficiently.
Recent long-term droughts and water restrictions along side States mandating a reduction in water use EG California as the 1st January 2014 mandated that domestic customers must reduce water use by 20% based on the 2013 consumption. Failure to do so will lead to stiff fines. http://www.saveourh20.org/
So will a combination of low water pressure and customer reluctance to hook up to their supply drive the US cleaner toward tank systems in 2015 and the future. Some major suppliers are betting on just that with a 1st to market product.
Within the UK and EU, many properties are now on water meters to encourage smarter water use, this is a policy that despite the last two very wet winters is sure to continue.
This will likely drive the need further for the cleaner to carry water to site.
Early distributors into the UK were Ionics. Omnipole, Aquafactors and Brodex. The early users were often limited to either a Tucker or Harris pole. Early adopters now had the tank in the van a battery for power and a delivery pump and there were set.
Or Were they?
As now the 100 PSI 5 LPM pump quickly became the pump of choice. Many of these early pumps came from the leisure caravan market as they had been used in 12V DC systems in showers or simply to fill your kettle or run a shower.
The pumps were not intended for prolonged daily use that they became adapted to. The pumps were capable of moving 300 litres an hour in open flow. In reality due to the restrictions of hose expansion, the length of hose and brush head jets approx a 3rd of this water actually reached the brush head.
Why use a Spring manufactured controller?
1. A pump running flat out often meant many found themselves running out of water before the end of the day of having to carry very large tanks with all the weight and load implications this entailed.
We have a pump operating at 100% trying to force 5 LPM into a hose the resulting back pressure and restrictions meant the pump was working against its self and drawing ever higher current from the battery. A 100 PSI pump can draw 7 – 10 amps in open flow.
2. Batteries did not last long. These early systems relied on the pump pressure switch to stop the pump when flow was shut off. As the pump is running flat out drawing close to its maximum amps potential there is a very large electrical load across the pump motor and pressure switch contacts. As the pressure switch cuts in and stops the pump the Inductive (stored current) load arcs across the pressure switch contacts and will burn them out.
3. As the pump pressure switch activates it is carrying a high conductive load (stored energy) This arc,s across the pressure switch and burns it out.
So in short, WFP although safer used a lot of water, can place a high load on pumps and batteries.
Well, some bright spark asked the question “ If I only need 1 LPM of water at the brush why not have the pump produce 1 LPM? “
This idea caught on and the first controllers came to market in the form of voltage regulators. This means the voltage to the pump is restricted to a fixed amount, in effect think of a light dimmer switch.
There is a down side to this method which I will cover later.
By reducing the speed of the pump the user noted a big difference in the amount of water used and the battery life.
Water use reduced and battery life increased, so now not only did the user have enough water to complete the days work often he had water left over. Also, he now had plenty of battery life.
SO time to go home then Or of course, what many chose was to expand their rounds and take on more work.
So how did the Spring range come about?
A number of years ago we were approached by a window cleaner in the south of England. He had quickly realised the potential of both WFP and a controller to manage the pump and improve efficiency.
His Brief was simple and Crow Electro, Mow Spring (Europe) Ltd were tasked with producing a voltage regulator to be used in WFP. The V1 analogue control was quickly in production and enjoyed some success
The addition of a voltage regulator reduced the speed of the pump, also reducing water use and battery power drawn.
The V1 as we called it in house was a success as it met it design requirement, EG allowing accurate control of the pump, ease of adjusting water flow and reducing the current drawn form the battery. The Pump was not working as hard which in turn reduced strain on the pump motor.
So Job done then?
Voltage regulators still relied on the pump pressure switch to stop the pump when water flow was stopped.
This meant that as the flow was stopped the pump motor and hoses were being placed under a high pressure and load. The pressure switch contacts arced due to the high conductive electrical load.
Result burned out pressure switches, blown hoses and connectors expensive downtime and replacements.
When a pressure switch fails on a pump it is not just the cost of replacing the pressure switch, time unable to work lost opportunities to quote and expand and develop the business, Sourcing the replacement part and fitting must all be taken into account.
At this point, it became apparent that further thought was required and that a control could begin to do more than just manage pump speed that it could provide a series of protections to the pump and, in particular, the pressure switch.
Following some discussion, it was agreed that Crow Electro (Now Spring (Europe) Ltd) would take the project forward and cover the cost of development design and production of the units. This also gave Crow ownership of the control and its intellectual design – and operation.
The next development
With the next generation controls had a micro processor and used PWM (pulse wave modulation ) as opposed to a voltage regulator.( a voltage regulator sends a fixed amount of volts continuously )
PWM allows the controller to manage the pump in a different way.
We are now sending a series of pulses (waves ) Think of a castle rampart The waveform in this case is square. PWM in effect is switching the pump on/off many 1000s of times a second by adjusting the time between the wave we can alter the speed of the pump.
Why I here you ask ?? Well if you ever played with an electric train
It can be difficult to slow a train to stop exactly at a station or unloading platform that as needed.
Because a plain voltage control lowers the power at the same time as it lowers the speed.
The train will stall and jog as you play with the control.
However with PWM, every pulse activates the full power of the motor. This kind of speed control allows the train to smoothly creep into every station position stop no matter the number cars attached and put on a smooth un-jerked train start as the control is increased.
That is the advantage of PWM ( Pulse-Width-Modulation ) versus the
simple analogue voltage control..
So using PWM gives us much smoother and accurate control over the pump.
The Spring analogue was also the 1st control to feature calibration. The controller had a manual calibration button on the side. This allowed the controller to operate with a very wide range of pumps and systems. We also added in Dead End protection (DE) this further enhanced the protection of the pump pressure switch as now the controller smoothly stopped the pump well before the pump pressure switch needed to.
The range also saw the addition of Solenoid controls tank filling and operation of other systems via a relay.
The first multi-function controller that integrated battery charging, Tank filling and switching a heater for a water heater was also developed using the analogue.
The V3 analogue proved very popular with a number of distributors expressing an interest. A reliable control robust very every day use that gave the window cleaner a number of useful functions.
While the analogue was a very reliable and popular unit it had no real way or providing meaningful information to the user.
Wee looked at building on a tried and tested platform that we knew worked, but how to improve?
The addition of a seven segment display allowing us to show three digit codes via an LED meant we can now display messages to the user, for example, DE appeared for the 1st time as did a calibration figure. The V6 came into being with a number of both V6 and V3 controllers still in use.
A number of users commented that the batteries on their systems were going flat as they had no way to see what the battery state was at any time.
The V9 saw a number of innovations over and above the V6. One of these was a volt meter built into the controller. This allows the user to actively see the available voltage at any time.
Having a voltmeter also meant fault finding over the phone became easier as in many cases the problem stemmed from faulty connections, Worn pump motor or damaged battery.
We also added a low battery cut off so in the event of the battery volts falling below 11V the control would shut down the pump to protect the battery and prevent lasting damage to the cell through insulation.
The V9 was the 1st controller with an auto calibration function. Making calibration to the pump and system easy. No more fiddling with a switch simply set the auto calibration mode and the control would calibrate its self.
We also added reverse polarity protection to prevent the processor being damaged in the event of miss wiring the battery to the controller.
Pressure switch detection also meant the control could now advise the user when the pump pressure switch had activated due to high system pressure
We also added a function that checked the circuit between the battery control and pumps to ensure that the pump was in fact in the circuit. This also is a very important safety test that the control carries out as in the event of a wiring fault simply getting very hot the control would now shut down the pump and stop current feeding a potentially dangerous fault.
Se we now have a PWM unit that is not just controlling the pump, It is also carrying out a series of safety checks on the system while you work away.
Surely we could not top that!!
Remember we are electronic engineers so the answer of course is we can.
The V11 has a more accurate Voltage meter, It is also very clever in the way it drops unused current back into the battery so extended the work you can do per charge.
This has another benefit in that the Controller runs cooler, less heat generated means less current wasted and more efficient use of the available current.
In Summary, then whichever method you use the results come not just from the equipment but the professional using them. Both WFP and Trad will provide good results and many use both. Safety is the key no matter how the job is done. If you do use a WFP and pump delivery system than a Spring manufactured pump controller will make the system more efficient.
As always the article is not about changing the world, But getting you thinking. Be safe out there.
Hard Working products for hard working people
The Water Controls people