Ideal 'flow rate' per minute

Discussion in 'Water Fed Pole Cleaning' started by Green Pro Clean Ltd, Jan 29, 2016.

Advertisement
  1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.
  2. Welcome to the UK Window Cleaning Forums.
    Starting or own a window cleaning business? We're a network of window cleaners sharing advice, tips & experience. Rounds for sale & more. Join us today!

  1. Green Pro Clean Ltd

    Moderator

    Joined:
    Jan 20, 2015
    Messages:
    5,171
    Likes Received:
    2,167
    When i first started seeking advice on WFP setups some years ago I recall a forum member telling me that the ideal flow rate to ensure a clean window was 1 liter per minute.

    Does anyone know if there is an actuall science to the math?

    1 liter per min would give a good 8.3 hours of work time off my 500 liter tank. :)
     
    Advertisement
  2. daveyboy

    daveyboy Legend
    Moderator

    Joined:
    Jul 10, 2014
    Messages:
    13,005
    Likes Received:
    4,683
    I don't measure my flow but if it goes a couple of inches before it starts to drop then that is perfect flow for me
    Just a trickle
     
  3. Green Pro Clean Ltd

    Moderator

    Joined:
    Jan 20, 2015
    Messages:
    5,171
    Likes Received:
    2,167
    No offence daveyboy1 was looking to see if any of our techy lads had an actuall scientific answer not just personal opinions. As i said no offence.
     
  4. daveyboy

    daveyboy Legend
    Moderator

    Joined:
    Jul 10, 2014
    Messages:
    13,005
    Likes Received:
    4,683
    No worries
    I reckon that figure was arrived at by trial and error to see what works best
    Don't know how you would work it out scientifically
     
  5. Jonathan Sanderson

    Jonathan Sanderson Active Member
    Member

    Joined:
    Nov 21, 2014
    Messages:
    228
    Likes Received:
    76
    It's al based on preference.

    As davey has said, there is variables.

    What size jets do you use, what flow rate is your pump etc.

    There is no scientific calculation as to how much flow rate is needed to clean a window. A slow flow rate can be used, but you will need to spend more time rinsing and scrubbing the glass.

    If you use a higher flow rate you can cut down your rinsing time and in some cases actually save water.

    I've known guys use 0.3 litres per minute with 1mill jets, and some guys use 3 mill jets and have about 5 litres per minute. Both can do the same job, but quality and speed can differ.

    I use 3 mill jets and get about 2 litres per minute at the brush head, as I feel this is a happy medium between water use, efficiency, and speed.
     
    • Like Like x 1
    • Agree Agree x 1
    • List
  6. Andy

    Andy Forum Addict
    Member

    Joined:
    Feb 7, 2013
    Messages:
    773
    Likes Received:
    158
    Must be what suits you. The only variables that would make a difference are after the water comes out of the jets. Brush size pressure on glass speed bristles ect. A variable speed controller you can adjust to deliver a Lt per minute out of jets what ever pump etc you have. I must admit it is a interesting question.
     
  7. Solarpanelcleanington

    Solarpanelcleanington Forum Addict
    Member

    Joined:
    Nov 14, 2015
    Messages:
    702
    Likes Received:
    158
    Depends on type of glass, speed, brush, phase of the moon. It would be good if we all measure how long it took the pump a litre (through hose and brush) on our standard setting. Maybe.
     
  8. spruce

    spruce Grand Master
    Member

    Joined:
    Jun 4, 2012
    Messages:
    2,536
    Likes Received:
    736
    Probably give you twice that amount. I estimate we are only pumping water cleaning residential windows for about 50% of our working day. The remainder is packing, moving and then unpacking, wiping sills, writing out tickets and talking. :)

    Commercial is probably 75 - 80%.
     
  9. spruce

    spruce Grand Master
    Member

    Joined:
    Jun 4, 2012
    Messages:
    2,536
    Likes Received:
    736

    I think Jonathan has summed this up well.

    When we started wfp we had 1/2" garden hose, 3mm jets, no flow controllers and a 5 liter pump. We got through water like anything. I had a trailer with 375 liters and had another 100 liters in my Suzuki Van.
    I was out of water by 3 o'clock most afternoons. I wasted so much water washing the windows, but rinsing was brilliant. I flooded the windows so it made little difference what type of glass it was.

    When Williamson's came out with the first Varistreams we bought one. By turning the flow down we were able to save water, but were slower during the day. I had enough water to last another couple of hours without touching the 100 liter backup. But all I was able to do was another 3 houses or so a day, which didn't equate to that much financially.

    Since then I have always maintained that a slow flow isn't everything. I needed a reduced washing flow and a fast rinsing flow for optimum results. I used to use 1.5LPM water flow at the jets. It increased to 2 LPM and higher than that now but I haven't measured it. With the 4040 we now have plenty of water so I'm not as stressed about 'wasting' water as I was. I'm back to 2mm jets as I find I can work better with those.

    Spring was going to bring out a 2 speed controller which was controlled by remote. They sell them in the States. For me that's an interesting concept. Wash with low flow, press a button and rinse with a fast flow, both user programmed. Not sure how well it would work in practice though.
     
  10. Trev81

    Trev81 Guru
    Member

    Joined:
    Apr 16, 2015
    Messages:
    1,067
    Likes Received:
    446
    I use around 2.3 litres per min with 2mm jets, find this a good flow for working quite quickly and to give a good rinse without standing there for ages. Like others say its what ever suits and also what type of setup your running, for trolleys and people not carrying lots of water then I guess the flow rate needs to be lower to conserve water more.

    650L does me about 25/30 homes (a mix of detached and smaller some with connies some without)
     
Advertisement