Clean It Up
UK Floor Cleaning Forum => Carpet Cleaning Forum => Topic started by: Maurice Brown on October 27, 2010, 06:04:04 pm
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Looking at a new 3 vac machine that runs on either 1.5" or 2" hose. Can anyone explain the theory behind why a 2" hose is better on longer runs or why it does't matter on shorter runs? Cheers
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It's all about numbers not rocket science but bigger is better :o the more air you shift the more moisture comes with it also when I moved from 1.5" to 2" and also a 2" bore wand then it got stuck to the carpet.
Shaun
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Its easy to think it out logically.
I read "the airflow of the Scorpion-3 has been measured up to an amazing 326 cubic feet per minute"
What do you think? Is it easier to move that air through a 1.5 inch hose or through a 2" hose.
The area of a 1.5" hose is approx 1.76
The area of a 2" hose is approx 3.14
When I changed my Scorpion over two years ago to 2" hose the difference was quiet amazing - as if the machine just began to breathe.
This tea time I have done 3 smallish carpets in the local main Toyota dealership, sales areas.
I took my rotary to go over them just to help with the drying.
Didnt bother taking the rotary out of my van - when I finished the three, the first carpet was touch dry, and that was only one hour after cleaning it. And the water was yuk.
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Imagine sucking a thick milk shake through a large diameter straw from McD's and then try sucking the same through a smaller normal diameter straw, which straw would you rather use to get the gunk into your mouth?
When I need to get the stuff up quickly, I use the large one.
I know which hose I wanna get, especially the one with less friction on the inside.
Grant
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Also because your machine is working and sucking easier it makes the vac motors last longer, I use 2.5" vac hose for my TM and it does dry carpets rather fast but the vac blower isn't worked as hard.
Shaun
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Where does it end, has anyone got 3 inches?
And at the end of the day you have to wonder if the custy would know any differnt to the little Porty Guy who has no petrol to pay, doesn't have to drive to Cornwall, sleeps at night knowing a vac motor is just a 24hr currier away. You have to think don't you.
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I see your point about where does it stop but if we want the power (and buy it) then shouldn't we use it to the fullest?
3 questions I get asked the most
1.How much?
2.How long will it take?
3.When will it be dry?
Question 2 and 3 can make question 1 more digestable.
Shaun
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2" hose compliments a tripple perfectly and it's worth the investment. I got some crush proof off ebay for £85 deliveredhttp://cgi.ebay.co.uk/50ft-2-Vacuum-Hose-End-Cuffs-/280580578320?pt=UK_HomeGarden_CLV_Cleaning_CA&hash=item4153e7dc10 Connectors and goodyear solution hose available too. There's a technique to coiling it up but fine when you don't fight it ;D I think Solutions do the softer grade and that is easier to handle.
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Three inch is already in use !
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The other option is 4 to the door with 2" for TM, 3" in use, don't tell me, only in Amerika.
Shaun yes I agree make the best of what you have and if it does help reduce wear and tear on blower then even better.
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The trouble is that the thicker the tube the harder it is to bend.
Shaun
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Accsesoryplanet (as Simons link) do very good prices and their stuff is good, but the 2" suction hose from Solutions Cornwall is very flexible and easier to roll up.
OK it may not be as crushproof, but I roll my hose up many more times then it gets run over! ;)
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Looking at a new 3 vac machine that runs on either 1.5" or 2" hose. Can anyone explain the theory behind why a 2" hose is better on longer runs or why it does't matter on shorter runs? Cheers
I think its to do with fluid dynamics. On shorter runs the flow is more likely to be laminar with a small boundry layer, but on larger runs it will be turbulent. Turbulent flow has a much larger boundry layer, which is a layer of effectively static air at the wall of the tube. On a wider tube the boundry layer is less of the total area, therefore more airflow.
Its been a long time since i did any fluid mechanics so i could be wrong, but you can read about it here.
Laminar flow - http://en.wikipedia.org/wiki/Laminar_flow
Turbulence - http://en.wikipedia.org/wiki/Turbulence
Boundry layers - http://en.wikipedia.org/wiki/Boundary_layer
Graeme
Access Cleaning Solutions
ETA - http://www.cartage.org.lb/en/themes/sciences/physics/mechanics/fluidmechanics/RealFluids/BoundaryLayers/BoundaryLayers.htm
this explains why you should keep your bends minimal etc and it a bit easier to digest than the wiki links.
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Do i need to understand the science, no
I do know that when i changed from 1.5 to 2 inch it was like adding another vac ;D
I suppose that an optimum point for hose size performance maybe even larger but the down side is inflexible hoses, although i likle the sound of the ones that Joe has :)
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Trust me Jim, they are very flexible compared to the "normal" ones.
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WOW...
Wasn't expecting as much feedback from you guys. I'll definately be going for the 2" hose and thanks also for the advice on the more flexible hoses Joe.
Just one other thing!! (There's always "just one other thing" - or maybe 2 or 3 ::)). All of my wands etc are 1.5", does anyone reduce the 2" to 1.5" to accommodate the smaller tool size and what length of 1.5" could or should be used without undoing the benefits. I have a number of nearly new 25' x 1.5" that I would be reluctant to butcher (chucked all the old ones out January), is 25' too long?
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You dont have to butcher any of your hose.
You can get a 2 - 1.5 reducing cuff.
However for stairs, and tight spots in small rooms you could do with a 5' or so of 1.5" so its more flexible. Some people manage though without this short "whip". 25' is too long IMO, the less the better.
You could always sell your newish 25' of hose.
I got some 1.5" I could give you 5' of it if you nearby to collect. Cheshire - whoops, just seen you are in N.Ireland
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I'd get yourself a 2" wand to be honest! 1.5" will soon seem like kids toys :)
After switching over to 2" all through you won't mind losing a bit off one of your old hoses. A 25ft whip line will choke your airflow, don't do it! I carry a 5ft piece with me that has a coolcuff reducer on it.
With a coolcuff on the end of my main 2" hose, I can quickly fix the whip line on and use any of my 1.5" tools like small wand or hand tool etc. Works a treat for me :)
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Great advice chaps. Now know what I need, many, many thanks.
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Do i need to understand the science, no
Well he asked why ;) and it sounds better than its sucks harder :-*
Next time someone asks why you have a thick hose, answer fluid dynamics ;D
Graeme
Access Cleaning Solutions
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The debate over 2" hose and wands against 1.5 can go on for ever and probably will. The answer with the individual is whether they believe that the priority is with better 'Airflow' or 'Water Lift'. I have come to my own conclusion after many years of going down both roads.
However to be honest, I think that if you have a powerful machine, it matters little which side you go with as the result and dry time is going to be excellent anyway.
If on the other hand I had a porty, 3 vacs and all, I know which way I would go.
Dave.
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Can anyone clarify this please?
When is a portable powerful enough to benefit from the increased hose diameter?
Do you need dual or triple vacs to make it worth while?
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You can't run 2" hose on a twin vac in-series machine (e.g. ninja). Because it doesn't have the airflow, recovered water just kind of sits in the hose rather than being pulled back to the machine. I know because I tried this myself. Also because you're relying on lift, the bigger volume inside the 2" pipe makes your vac less efficient. Better sticking to 1.5"
Not sure how 2" would work on a twin vac parallel such as an alltec pro plus... probably similar result seems as you don't have much lift. but I'd stand corrected, never tried it.
I think velocity plays a part, but I'll let Graeme come back with the Carol Vordermann bit seems as he's doing a great job of it so far ;D
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You can't run 2" hose on a twin vac in-series machine (e.g. ninja). Because it doesn't have the airflow, recovered water just kind of sits in the hose rather than being pulled back to the machine. I know because I tried this myself. Also because you're relying on lift, the bigger volume inside the 2" pipe makes your vac less efficient. Better sticking to 1.5"
Not sure how 2" would work on a twin vac parallel such as an alltec pro plus... probably similar result seems as you don't have much lift. but I'd stand corrected, never tried it.
I think velocity plays a part, but I'll let Graeme come back with the Carol Vordermann bit seems as he's doing a great job of it so far ;D
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It's simple. No Carol Vorderman required. Larger diameter hose offers less resistance to the flow of air through the pipe. So larger pipe is better. Can't comment on Jim's in-line vac motor problems. But with my old porty which is a Grace twin vac, 2 inch hose allows me to use longer hose runs without suffering performance problems. Which is nice.
However if Carol is lurking out there and she disagrees, I won't be making an issue of it. :)
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I'd love to work it out with Rachel Riley :-*
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Jim
Surely if there's a vacuum in the hose then the
water can't just sit there.
Atmospheric pressure will still force it up the pipe.
John
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Atmospheric pressure ???
John that's exactly what it does do, sits there with air passing over the top of it. There isn't enough velocity to pull the water back to the machine, only the air.
Imagine if you stuck a 4 inch drainpipe into your bath and tried to drink through it... wouldn't work would it!!
Try it, you'll see ;)
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Your example explains it well, know a woman that could though. ;D ;D
Thought atmospheric pressure was what caused the airflow, the old
high pressure low pressure thing.
John
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How about your thoughts on this?
I've got one of the older CFR machines with a single vac. I presume I'm looking at airflow more than water lift here.
The normal (30 foot) 1 1/2" hose works fine.
When I add an extension hose (extra 20 foot) to help on upstairs rooms, landings etc, the solution recovery is still good but the extra drag is quite noticeable.
Do you think having a 2" extension pipe (only) coupled to the normal 1 1/2 pipe would be any improvement?
Garry
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No, it would be worse than the 1.5" because the vac motor is having to create a vacuum in a space double the size (the cross-section of 2" hose is roughly twice the area of 1.5"). Yes, it would mean less resistance to air, but would not recover liquid as well.
And you're looking at airflow AND water lift, but in very small quantities!!!
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Thanks Jim,