i dont know if this going to help any one but just want to say if you are confronted with really dirty windows and the situation allows try this…
i´ll say again if the situation allows …
i use this very effective process now and then …( example — once yearly or a first clean )
if the residential commercial property you are cleaning is really dirty and has for example other things around or on the window that are also to be cleaned … example again in Germany many house have outside sun blinds ( Aluminium ) or Rolladen ( rolling sun shutters made of UPVC that roll down from above the window either manually or electronically to cover the window … these are often caked and its pointless attacking these with a cloth and a bucket … get my jist ???
Try this … if the house or property has water taps outside rig up a hose thats running off normal tap water and is of suitable length wash your area down ( break the job up into blocks ) with a soap of choice then rinse down with the same tap water hose and washing…( i use Ecover ) the crux is if the water has a high TDS its ok but you have to attack one area at a time before the Tap water dries … other wise it will leave lime scale… (white spotting from the minerals in the tap water )
Then after doing this wash down with Tap water and the hose ( with those adjustable garden hose hand guns… spray light spray mist … normal mode )
then !!! rinse the area down with a small pressure washer a (25 L ) Barrel of PURE WATER !!! its extremely surprising how little pure water is needed to rinse down the tap water …
because the flow rate is much greater than a Normal WFP the rinsing is not only much more effective but obviously much quicker and if you get your technique right !!! you will leave the window spot free and looking much cleaner than if you had used a Wfp… Wfp has its place Yes of course … but certain situations call for another approach.
Doing it this way you will save greatly on Pure water costs because the high flow of the Hose water gets most of the job done and speed of the pressure washer and pure water gives that final rinse
So using this process i have cleaned the sun blinds inside and out the window frames the sill and the window glass ( one guy is cleaning from the inside opening and shutting windows in tandem with me )
You dont have to buy an expensive rig… you just need a suitable garden hose with Spray gun to connect to the tap water on the job
one 10 m or 20 m Pressure washer hose ( LIGHT WEIGHT )
a Pressure washer hand gun with quick release nozzle connection or vario nozzle
a low pressure Pressure washer with around 80 - 120 Bar ( 1160 - 1450 PSI )
with the ability to suck from a stationary container
( this reduces the pressure to nice rinse flow but a flow rate that is not going to cause damage )
and trolley to transport the Pure water barrel …
if you get some strapping or bungee chords you can attach you pressure washer to the trolley …