[Robin Ray]

Does anyone use 2" hose on a 2 motor machine?

I know many say this will not work however the woodbridge machines all have 2" hose and some of them only use 2 x 2stage motors. I havnt tried them or even 2" hose. I was just wondering if it would make much of a difference on my Ninja?


Thanks
Rob

[Jim_77]

Won't work, stick to 1.5

I have posted a pretty long reply about this before I think, have a search, much more info in that same thread

[Robin Ray]

Hi Jim

Just read through your post. Not saying your wrong after all you have tried it. But thinking about it if you have a higher water lift rather than air volume would you not have the ability to suck/ lift the water sitting in the hose further. Therefore a machine with less cfm but more lift should have the ability to move more liqid through a larger diamiter tube, maybe at a slower rate. You used the illustation of trying to suck water up using a drain pipe rather than a straw. Surely a machine with higher lift would perform this task better than one with high CFM. Just like a vehicle with more torque can tow a heavy trailer but a vehicle with more bhp can go faster yet not be able to tow as much weight.

All theory of course.

Im not trying to start a debate of lift over cfm.It was just a thought.

Rob

[nevil]

Sorry Jim but got to disagree. I used 2 inch hose with mine and the improvement was immense. Greater diameter means less resistance to air flow. Which means more air will flow. End result is better airflow in short hose runs and longer hose runs are possible without reducing performance as much as smaller hose will.
If you want to eek out every last bit of available performance from a porty, 2 inch hose is a must.

However larger hose is much harder to manage.

[Paul Simpson]

I use 2" hose with my 3 vac machine but it developed a problem recently and I had to use my twin vac back up machine for a few jobs with the 2" hose and have to say it performed pretty well.

And to think I was going to sell my back up but obviously not now.  

[Jim_77]

Air flow x aperture size = velocity (or something like that).  The theoretical "air movement" principles on paper are fine, but we're not trying to move air around, we're trying to move fluid and solid matter.  If you haven't got enough velocity you can't shift heavy stuff like fluids.

Vac motors have to create a vacuum in the system before anything happens.  2" hose has roughly twice the internal volume of 1.5" hose, therefore it takes twice as much effort to create a vacuum in that space.

Yes, the air flow resistance of 2" hose is much less but without velocity and with the longer time taken to build up a vacuum when the wand is placed on the carpet, performance is reduced but in a different way

The proof of the pudding... when I have tried using my Ninja with 2" hose and wand, it ends up with loads of dirty water sitting in the hose which you have to hold up in the air and "tip" back towards the machine before you switch it off, otherwise you'll end up with it dribbling all over the place!

Interesting that you have found different Nevil - was it a 2 vac machine in series or parallel?  Parallel would definitely be much more suited to 2"

[Dave Roelants]

On the very rare occasion I have to use a portable it's a mytee speedster and I always use it with 2in hose, it makes a massive difference to airflow which is of far greater benefit than lift if you want to leave carpets drier

[nevil]

Hey Jim it's a real curious one that we have had such different results. My machine has vac motors in parallel. So configured for cfm.


I would argue that the vac system is there to move the air as quickly down the pipe as possible. And it's this velocity that enables it to carry the water. therefore less restriction will enable greater velocity and greater ability carry moisture. In the real world, with the wand on the carpet this velocity is greatly reduced. Anyhow enough of the scientific waffle, the only thing I care about is it works and works well. I can use 75ft now whereas with 1.5 inch I didn't even like to go up to 50ft. Are you sure you had it switched on?

[Robin Ray]

At present I have a ninja which is two in series and I use 50ft hose most of the time and 1.5" hose and get excellent drying times. Maybe its because I dont know any better.

[nevil]

If you want to borrow some 2 inch hose for testing Robin that's ok. I can't give you the cuffs though. I only have a couple which I use a lot so would miss them.

[Jim_77]

Well that's the difference then Nevil, parallel vs series

You portable has twice the airflow but half the lift compare to mine.  Therefore the 2" hose's bigger volume means the already low lift is just a bit lower so doesn't affect much, but the lesser resistance to air flow is letting your machine work better!

Whereas with my ninja the lesser resistance to the already low airflow doesn't give any advantage, but having to work 2x as hard to create the vacuum in a bigger space is bùggering the whole thing up!