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speed and water

chip

Well-known member
Messages
1,327
some time back i did an experiment, even drew up an algebraic formula but can't find it.

anyhow, i set the pump to a low flow and cleaned a window to my satisfaction and timed it and worked out the water usage. did the exact same experiment with a higher flow, and it worked out i cleaned the window faster and used less water! about 10% i think it was. obviously there's a few variables to consider, my opinion of satisfactorily rinsed might not be yours but that' basically irrelevant. what is relevant is how fast you can physically wash a window, a slow worker will waste water, a fast worker will waste time, and of coarse whether you turn off between windows, etc.

still, i think there's a potential to increase speed and save water

 
This is very interesting Chip! I find If I set my pressue at around 15 & work quickly I normally will save water than if I say set the pressure at around 30-35. But I guess everyones different. I'd be interested to see this formula you have created!

James.

 
what it boils down to, mainly, is the rinse. if you're like me if the waters coming out slow, you'll move the brush to and fro slowly and try to hit every bit of the window, if it's coming with a bit of force, you can be rinsed in no time and as the water is running down the window like a torrent, you have more confidence that it's all rinsed, if you get my drift.

 
Forget flow controllers! turn your pump up as high as it can go!

You will as you say chip will not use any more water as you can clean faster! trying to save water slows you down! (the higher the flow the faster you go!)/emoticons/smile.png

 
Screw pencil jets, fan jets are the way forward! Apparantly a friend of mine said there is no need for rinsing at the end of the clean as if your waters on 0ppm it will dry naturally.

My argument was the rinsing gets rid of any bits and pieces (dried cobwebs etc) and leaves a perfect finish. He says otherwise.

James.

 
in theory i don't think it's usually nescessary- if the flows high enough you've got water rinsing while washing. in practice i'm in your camp james, have to rinse!

exception being if it's to awkward to, in that case i wash the window and then run it across the top of the glass a couple of times.

i don't have flow controller either james, can't see the point just alter the pump accordingly. think you need a by-pass though, not sure.

 
Ahh right, I'm not too sure on the pump/flow controller. It just kinda came with the van already built in so I just got used to it. But yeah just altering the pump would be just as easy tbh.

James.

 
I have fan jets and always rinse, one thing you can do over pencils is rinse on the glass, this is very handy when doing windows at height.

 
I have fan jets and always rinse, one thing you can do over pencils is rinse on the glass, this is very handy when doing windows at height.
Yes, deffinately agree, big advantage when doing windows at 3 storey height!

James

 
been through the archives and dug out the equation (just for you james)

L/60xT which is to say litres per min diveded by seconds per min multiplied by time taken.

my experiment went thus:

slow flow 800 ltrs per min, so

800/60=1.333r ltrs per sec

1.333rx12 (seconds taken) =1.5999r liters used

higher flow

1200/60= 20 ltrs per sec

20x7 (seconds taken) =140 or 1.4 ml to clean it.

 
been through the archives and dug out the equation (just for you james)

L/60xT which is to say litres per min diveded by seconds per min multiplied by time taken.

my experiment went thus:

slow flow 800 ltrs per min, so

800/60=1.333r ltrs per sec

1.333rx12 (seconds taken) =1.5999r liters used

higher flow

1200/60= 20 ltrs per sec

20x7 (seconds taken) =140 or 1.4 ml to clean it.
Very impressive chip!

I'm going to use this equation to do my own little experiment /emoticons/biggrin.png I'll post you my results.

James.

 
?????? i've only had pencil jets & i always have rinsed on the glass i was told it depended whether your brush is flocked (off) or unflocked (on) but ive no idea what my first 2 brushes were & they were always ok but i use a backpack dunno if that has a different flow

 
your right if you use fan jets with a flocked and rinse on the glass you could be head for trouble as the flock brush tends to hold the dirt

I have my pump on flat out but i use a 60 m hose and was told that the pumps work best when run flat out could be wrong but my pump is over 18 months old with no worry about the controller playing up

rinsing on the glass is the way to go as long as you use right brush and can be confident the brush isnt holding dirt.

 
Just out of interest. If anyone uses Gardiners Medium Dual Trim Sill brush, does it hold dirt, spider webs, etc. I've noticed mine is starting to hold quite abit of dirt. Is it when the bristles start to wear/flare out?

James.

 
‘Static’ water of 1 litre will cover approximately 1 square metre of glass

A typical residential window pane of 18”x 36” (aprox 40% of a sq metre) won’t necessarily need 400ml of water to clean (aprox 12 seconds cleaning time, with 2lt per min)

‘Active’ flow rate of just over 2 litres a minute will give you 34 millilitres of water per second (about a cupful 250ml of water every 7 seconds) which can be more than enough water to clean 18”x 36” window that is maintained regular

The final rinse won’t and shouldn’t always be necessary on every pane of glass you clean. Glass type has very little to do with the final cleaning results,

Match water flow rate to your speed of working, adjust flow rate up or down accordingly to match your speed so you either don’t waste water or valuable time.

Choice of wfp equipment is important and this does affect final cleaning times; differences in times will be substantial at the extremes, the knock on effects to this can be dramatic for a business.

Richard

 
Jesus you guys are to intellectual for me with all these equations, my equation is 1xdirty window add water approx-just enough until clean = happy customer = me paid :huh: that took a while to cum up with but I think I've got it

 
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