[The Carpet Cleaning Pro]

When I use my 14" wand it doesn't seem to vac us good as the 12" I normally use. If I get 15 hg with the 12" wand and then swap it for the 14" wand the lift drops to about 10 hg.  I can not work this one out as both seem to lay on carpet pile ok. The only thing I have noticed is the 14" wand is lighter in weight. Would a glide on the 14"wand  perhaps help create a better seal at the carpet pile?

[Adam Fearnley]

The bigger the intake area of the wand the slower the air moves so it will be a little less effective.

[Simon Gerrard]

Mick,
Is the 14 inch wand a 2 inch stem, like the Titanium?

Simon

[The Carpet Cleaning Pro]

no both wands are 1.5".

[Kinver_Clean]

The airflow and vacuum are related proportionately. The vac units will only deliver a certain amount of vacuum at a particular airflow. Airflow is in proportion to the resistance in the tool/pipe. This is affected by the size of the hole in the end of the pipe. If there is no tool or restriction on the pipe there will be high airflow and low vacuum, if you have a small hole (the wand on carpet) then the vacuum will increase.
So, if you have a 12" tool on it with a 1/4" wide slot you will have 3 sq ins of hole. If you increase this to 14" then you will have 3 1/2 sq ins of hole. The formula for calculating this is complicated and involves sq roots and other nasties. It is also complicated by having carpet obstructing the hole.
Basically if you increase the size of hole (from 12 to 14" ) then you will get more air but less vacuum.

[bennymon]

Just use the 12 mate

[nevil]

Sounds to me like the 12 inch wand is restricting flow too much. At 15 hg you must be very close to opening the vac releif on the waste tank. If it is opening then it's a complete  and utter water of fuel. The idea is to have as much air flow as possible which means not forming an air tight seal on the carpet. I would guess you will get better drying times with the 14inch wand.