Window reach & wash
Water and squeegee
Generally, chemicals are added to water, and a device such as a brush or cloth-covered handle is dipped into the resulting solution and used to scrub glass.
A squeegee is then used to sluice the dirt and water mixture from the glass. Chemicals added to the solution range from dish soap and glass cleaner to Trisodium Phosphate and etching salt. In sub-freezing temperatures, anti-freezing chemicals are added to the solution to prevent it from crystallizing on the pane before it is sluiced off.
Any of a variety of types of telescopic poles, fitted at the upper end with a brush and water jets, fed either from vehicle-borne tanks of deionised water or by on-site production of deionised water using a domestic or commercial water outlet. The water is filtered by either a two-stage or three-stage filtration process, involving a carbon filter, and two de-ionization filters, or a carbon filter, a reverse osmosis membrane filter, and a de-ionization resin filter.
The brush is used to agitate the debris off the window, while spraying water, and then the brush is lifted a few inches from the glass to rinse the glass with the pure water jets. Fan jets are used for hydrophobic glass, and "pencil" jets are used for hydrophilic glass. The de-ionized water is lacking in ions, so it will pull solids off the glass and dissolve the solids into the water, aiding in the cleaning process. Because there are no solids dissolved in the water, the windows dry clear without water spots.