CFM v.s. LIFT

This question has already been answered on this board in detail by me a couple of months back, but to give you the abbreviated version it is all a matter of cause and effect. Lift is what causes air to move, while air movement(cfm) is the effect of providing that lift.

Thanks I thought I asked on another board. By the way,Ken where have you been I have not seen you around ccs much in the last couple of days.

Edited by rmarkham

Ok I'm gonna take a shot at this, and keep in mind this is coming from someone who has never used a professional carpet cleaner in their life.

A vacuum works by using the force of the air moving into the wand to remove the bulk of the water, not the actual vacuum. The further the water is from the source of the vacuum, the less force that is exterted on the water by the air moving into the vacuum, resulting in less water being removed. This is where a good aereodynamic glide and wand comes in, to maximize the usefullness of the airflow entering the vacuum hose.

To maintain the maximum amount of air entering the wand, it is neccessary to maintain the highest level of vacuum possible. This is where things get complicated.

Air is screwy because is not in a static form such as electricity or water. Simply put, air can be stretched where water and electricity can not. The higher the level of vacuum, the less CFM at 1 atnosphere your blower can move per revolution. This really comes into play when you have a long length of hose when you have a bunch of "stretched" air in it.

So for a good vacuum you need a blower capable of maintain a high degree of lift, such as a (positive displacement, the air is removed from the blower on each revolution whereas on a centrifugal blower you have the force of the atnosphere wanting to hold the air in the impeller blades, hence the multiple stages needed) and lots of CFM moving ability to maintain the lift under load.

Edited by Dixiedrifter