Pure water and window cleaning are the natural progression of the next major milestone in Window cleaning.
The R/O DI
systems are the future for window cleaning for buildings
4 to 5 stories and under.
There are new poles and pumps and getting DI tanks is getting easier.
The best way to start out is buy a pole from a vender who will help you out by not just selling you something to make a sale
but sees what your budget is and how high you need to go.
You should be able to get into the WF market for under $1,000.00 with most of that money going toward you pole
and then renting a DI tank and adding a charcoal filter.
You need a TDS meter
to find out what your feed water is because if it is high your DI cost will go up.
If that is the case then you might want to get an RO unit to make from 1,000 to 3,000 gallons of water a
day and finish it off with a DI tank.
A De-Ionization Tank (DI Tank) is filled with a mixed-bed of resin beads that are positively and negatively charged.
The Total Dissolved Solids
within typical tap water have either a positive or negative charge.
As the tap water passes through the DI Tank (or DI Cartridge) the dissolved particles attach themselves to the oppositely charged
ions and stay within the DI Tank (or DI Cartridge). The finished water continues on, 99.9% pure. Depending on local water hardness
a DI Tank (or DI Cartridge) will become saturated after a certain period of use. The resin can then be regenerated
in the DI Tank almost to its full capacity making the use eco-friendly at a fraction of the cost of new resin.
- Versatility, portability, compactness, user friendly
- Modular design allows you to add capacity as your needs and cash flow grow
- Optional d.i. cartridge mounts directly to frame for competence and convenience
- Use as stationary installation in your shop or mount in your trailer, van or truck
- Inlet pressure gauge monitors inlet water pressure and condition of pre filters
- Outlet pressure gauge monitors pressure to membranes
- Choose 900, 1800 or 2700 gpd (1.9 gpm) capacity
Source: Phillip Alexander
Several years ago, actually in the last millennium, I wrote an article for the AWC, titled Window Cleaning In The 21st Century.
In it I mentioned all of the innovations in our industry since the invention of the squeegee. Then, I got to pure water and wfps.
There is no doubt that pure water and wfps are the best thing that happened to our industry since 1936. We can clean more exterior
windows in a day then ever before. And we do it safer!
When I wrote the article, there was only one manufacturer of pure water equipment in the USA (that does not include DI tanks).
Now there are three. I suspect there will be more at the next trade show.
The technology is simple:
Take the impurities out of the water and you get a spot free rinse. Add a wfp to that and up we go…as
high as sixty feet!
So then, what does one need to jump on the technological band wagon? That is a bit more complex.
Enter TDS: Total dissolved solids
, the impurities in the water.
The deionization process removes TDS by an ion exchange. It isn’t necessary to understand the process, just like it isn’t
necessary to understand how a car or a TV works. As long as they do, no problem. It is only when they quit working does a problem exist. DI will quit working rather rapidly in areas of high TDS. The good news is: there is a solution. DI resin can be regenerated. It can be a bit of a hassle for small companies, as you have to bring the tank to the re-gen place. That is time lost from work.
Multi stage filtering:
This is the answer for areas of high TDS. Multi stage filtering machines remove most of the TDS before
the water gets to the DI filter, leaving that filter with little to do. Obviously, the DI filter lasts a lot longer. Filters
are shipped to you, so there is no down time having to shop for them. There are units to fit the needs of all users. Many of
the portable units produce ½ or more gpm. It only takes ½ gpm to clean windows. Some units will run two or more poles at the
same or slightly greater gpm. And there are units that large companies use to fill tanks on the trucks they send out.
They produce a lot of water.
They are a bit pricey, but well worth it when you do the math.
Again there are poles for every budget and every job that they are designed to do. Carbon Fiber is the lightest…and the
most expensive. Fiber glass is less expensive, but not designed to work the heights of carbon fiber. Aluminum poles are good.
As in anything else, some are better then others. Some have better locking systems and are made of heavier gauge aluminum.
If you are considering stepping into the 21st century, do your homework. Look for the unit that fills your needs. Get the best you
can afford. Scrimping on tools is never a good idea. Most companies have leasing plans to make it easier for you to get the right
product for your needs. It would be foolish to spend your money on a DI tank if your TDS is high. If you plan to use the wfp on a
regular basis, consider a good one. There is no substitute for good tools.
If you can do twice as much work in a day for one initial cost and small intermittent costs, will you make more money?
Assume that you can lease a complete system (poles included) for around $450 per month. How many jobs does it take to make that payment?
One, two? How many more jobs could you do in a month with the equipment. Do Ya think it pays to step into the 21st century?
How It Works
Water is pumped through a hose reel, up a telescopic Water Fed Pole and through jets in the brush where it is
sprayed onto the glass.
When the brush contacts with the surface of the glass and frames, it lightly agitates the surface, loosening the dirt.
Any dirt or dust particles are flushed away by the constant stream of water.
What would happen if normal tap water were used to wash a window?
It will result in the glass appearing milky white in color when it dries, and you will be able to write your name
on the glass surface with your finger. Try it! This effect on the glass is due entirely to the mineral content of the tap
Water Fed Pole Systems work because they use the equivalent of water.
That is: Water without any mineral content, or demineralized water, so that when pure water dries it leaves the
windows perfectly clean. In addition, pure water does not exist naturally and will always absorb atmospheric elements as
it returns to its natural state. When applied to the window, pure water automatically absorbs the dirt.
All water from out of a tap contains a quantity of minerals. The quantity differs from one area to another because of the
variety of enviroment and ground rock strata that rainwater passes through before it reaches our rivers and ground-water
storage reservoirs. If you were to buy bottled spring water from the supermarket and read the analysis label you will notice
that water contains minerals such as calcium, magnesium, chlorides, nitrates, sulphates, bi-carbonates, sodium, potassium
and silica etc...that are dissolved in the water.
A TDS meter is required to identify the total quantity of
minerals that are dissolved in your water.
TDS: Total Dissolved Solids.
This hand held meter will give a three digit reading.
If you were to test the water at your tap, the meter would probably show a reading of between 035 parts per million (035 ppm)
and 600 parts per million (600 ppm)
This is ok for drinking, but it is not of any use at all for window cleaning!
If you want to wash glass and end up with perfectly clean windows, all the minerals need to be filtered or extracted
from the water, giving a TDS reading of 000 ppm indicating zero mineral content or total demineralization.
The costs and methods involved in demineralizing water with a TDS of 035 ppm is far less than water with a higher TDS of 600 ppm
There are a number of different methods used to produce demineralized water.
This is important to remember. Some methods are just too expensive to even consider.
The methods that are cost effective are listed below.
You will need one of the following demineralization systems:
A de-ionized resin vessel on its own.
sometimes called a polisher
A de-ionized resin vessel and a reverse osmosis filter along with pre-filters.
A de-ionized resin vessel, a reverse osmosis filter along with pre-filters and a water softener.
Which Water Fed Pole System is best for you?
The answer depends upon an analysis of your water. As a general guide, consider the
A: If you have very soft water, Option 1 would be cost effective in the short term.
B: If your water is harder, you may need Options 2 or 3 depending on calcium and
In simple terms, reverse osmosis is the process of pushing a solution through a filter that traps the solute on one side and allows
the pure solvent to be obtained from the other side. More formally, it is the process of forcing a solvent from a region of high solute
concentration through a membrane to a region of low solute concentration by applying a pressure in excess of the osmotic pressure.
The membrane here is semipermeable, meaning it allows the passage of solvent but not of solute.
The membranes used for reverse osmosis have no pores, the separation takes place in a dense polymer layer of only microscopic thickness.
In most cases the membrane is designed to only allow water to pass through. The water goes into solution in the polymer of which the
membrane is manufactured, and crosses it by diffusion. This process requires that a high pressure be exerted on the high concentration
side of the membrane.
How R/O Works
Reverse Osmosis uses a very fine filter or membrane. The membrane is so fine that the pores only allow passage of water molecules.
The dissolved impurities do not pass through the membrane.These impurities can include calcium, sodium, and other elements that
normal water can contain. The membrane itself is made from a synthetic material, such as polyamide or polysulfone.
This membrane is delicate and could be damaged by organic matter, iron, chlorine, and other impurities found in normal tap water.
These impurities must be removed by pre- filters.
This membrane, begins as a large flat sheet, is spiral wound into a tube , and housed in a pressure vessel.
The pressure of the water entering the vessel is sufficient to squeeze the water molecules through the membrane to produce a
flow of pure water. The remaining water passess through the vessel carrying the impurities with it and exits to waste.
This is known as reject.
The reject water has a higher content of dissolved solids but is not hazardous and can be safely drained away.
RO membranes will produce a large quantity of pure water cheaply.
Keep these points in mind:
- Change your filters regularly
- If the water in the RO unit freezes, that unit will be permanently damaged
- Soften the water. Water softners exchange calcium and magnesium ions with sodium.
Sodium helps hold the other remaining suspended solids in the solution, preventing them from adhering to the membrane surface.
A water softner will prolong the membrane's life.
Deionized water (DI water)
Deionized water (DI water or de-ionized water is water that lacks ions,
such as cations from sodium, calcium, iron, copper and anions such as chloride and bromide. This means it has been purified from
all other ions but H3O+ and OH-, but it may still contain other non-ionic types of impurities such as organic compounds. This type
of water is produced using an ion exchange process.
Deionized water is similar to distilled water, in that it is useful for scientific experiments where the presence of impurities may
The lack of ions also causes the water's resistivity to increase. Ultra-pure deionized water can have a theoretical maximum resistivity
up to 18.3 M-·cm-1, compared to around 15 k-·cm-1 for common tap water. Deionized water's high resistivity allows it, in some very
highly speciallized instances, to be used as a coolant in direct contact with high-voltage electrical equipment. Because of its high
relative dielectric constant (~80), it is also used (for short durations) as a high voltage dielectric in many pulsed power applications,
such as Sandia's Z Machine.
Deionized water easily changes pH while storing it. This is because carbon dioxide from the air dissolves in the water and causes
a drop in pH by forming carbonic acid H2CO3. Boiling the water will remove the carbon dioxide to restore the pH.
The uses of ultrapure deionized water are many and varied, often having application in scientific experimentation such as when very
pure chemical reaget solutions are needed in a chemical reaction or when a biological growth medium needs to be sterile and very pure.
DI water is also used extensively in the semiconductor industry to process and clean silicon wafers and sometimes in the optics industry
when very highly clean optical surfaces are required for coating.
DI water is also often used as a final rinse when washing scientific glassware.
Deionized water is very often used as an "ingredient" in many cosmetics and pharmaceuticals where it is sometimes referred
to as "aqua" on product ingredient labels. This use again owes to its lack of potential for causing undesired chemical reactions due
to impurities. A recent use of DI water is that of window cleaning where because it contains so little dissolved
solutes so the glass dries without leaving any spots.