Here is a tool that you might not have thought about for cleaning windows.
I don't mean water alone, or just water but rather purified water, specifically, de-ionized water.
When regular tap water is sprayed onto glass and allowed to dry, everything that is in the water is left behind on the glass when the water evaporates. The things we as window cleaners are most concerned with is the minerals as they can build up on and bond to the glass forming hard water stains.
I've heard many times here in Redding "we have really hard water" but the truth is, we have better than average water hardness. The mineral content in water is measured in TDS or Total Dissolved Solids. The national average in the US is about 200 parts per million (ppm) with some locations measuring up to 400-500 ppm. The highest we've ever measured in Redding was 114 ppm.
Even though we have lower than average, anything above 000 ppm will start to leave water spots, and the more water that is allowed to hit a window and dry and for the longer this happens the worse the water stains become.
We therefore use a De-ionizing filter to filter the minerals out of the water before it is fed into our Water Fed Pole (WFP) to clean windows. The pure water comes out of the filter, is fed into our 150' of hose that connects to a brush on the end of our carbon fiber pole (it needs to be carbon fiber because at 32' long it would be too heavy and floppy if it was made of aluminum or fiber glass) and comes out 4 pencil jets in the middle of the brush.
With this set up, cleaning a window is rather straight forward, we scrub the window while the water is being fed through the brush and this dissolves and dislodges the dirt and gets it off the surface of the glass. Once things have been sufficiently scrubbed we lift the brush head off the glass and rinse the glass from top to bottom, making sure to rinse every square inch. The pure water washes the dirt off the glass and since the little bit of water left on the surface of the glass is pure, it is left to dry on its own and won't leave any spots since there is nothing in the water to be left behind.
We had one customer that I remember, he expressed concern that we weren't squeegeeing the water off the window. I explained how the tools worked and he took my word for it and I got back to work. Later on in the job as some of the first windows we had done finished drying he commented (with amazement) at how clear they were. He was surprised and how clean they could become with just water (though not JUST water, de-ionized water)
We love the WFP for a few reasons, most of all because it allows us to access windows up to 35' high, but also to access those and lower windows without having to use a ladder, and that means we are much safer.
The use of a WFP and pure water is not the answer to every problem. The brush for one is not the most powerful scrubber in our arsenal, and so on very dirty windows it can't get them as clean as we can when we clean them by hand, but if the windows were cleaned last year or more recently it does a stellar job making those windows shine.
Thanks for reading and if you live in Shasta County and need your windows cleaned, your gutters cleaned, or your screens repaired, don't hesitate to give us a call.