[Maurice Brown]

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

[Shaun_Ashmore]

It's all about numbers not rocket science but bigger is better 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

[Joe H]

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.

[Grant Whyte]

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

[Shaun_Ashmore]

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

[wynne jones]

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.

[Shaun_Ashmore]

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

[Simon@arenaclean]

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 I think Solutions do the softer grade and that is easier to handle.

[robert meldrum]

Three inch is already in use !

[wynne jones]

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.

[Shaun_Ashmore]

The trouble is that the thicker the tube the harder it is to bend.

Shaun

[Joe H]

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! 

[Graeme@Access]

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.

[james roffey]

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 
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

[Joe H]

Trust me Jim, they are very flexible compared to the "normal" ones.

[Maurice Brown]

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?

[Joe H]

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

[Jim_77]

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

[Maurice Brown]

Great advice chaps.  Now know what I need, many, many thanks.

[Graeme@Access]

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

Graeme
Access Cleaning Solutions