[Dave_Lee]

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.

[garry22]

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?

[Jim_77]

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

[Vernon Purcell]

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

[nevil]

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.

[wynne jones]

I'd love to work it out with Rachel Riley 

[JandS]

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

[Jim_77]

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

[JandS]

Your example explains it well, know a woman that could though. 

Thought atmospheric pressure was what caused the airflow, the old
high pressure low pressure thing.

John

[garry22]

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

[Jim_77]

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!!!

[garry22]

Thanks Jim,