What does "water lift" mean pertaining to vacs, and extractors?

[General Lee]

You always see extractors and some vacs listing there specs, and one of them is for example 95" of water lift. Different models vary in the water lift measurement But I ask: What the h*ll does water lift mean? I assume it is a power rating but how do they come up with that?

 

[q_tip98444]

The water lift, is how far a vacuum can pull water up a tube, the 95 mean that it can pull water 95 inches up in the air when the hose it put on one end of the tube while the other end sits in a pool of water. That is what I have always know it to be anyways. So basically, something with say 100 in. of water lift, will/should have more suction that something with say 80in. of lift. Hope this helps.

 

[General Lee]

q_tip- that definitly makes sense. I have a new extractor that has 91 inches of lift so that got me wondering. If you think about it, 91 is a long way to draw water up a tube and that sounds like decent power for a small portable extractor. Thanks for the reply.

 

[scottlee]

the vacuum industry is very deceptive on their ratings

although the inches of water lift is very important in a vac or extractor you also need a good balance in cfms also (cubic feet of air moved per minute)it gets very tricky, i went to a vacuum cleaner forum of all places to learn about this myself in the past.

you need a high volume of cfms also to really move the air as well to have the best suction but its very hard to find products that actually rate both cfms and water lift, also amp ratings dont aways mean more suction it means more energy useage, after reading up on this subject i am still confused

 

[Ed Hartman]

Scottlee is right. There is the debate in the industry on CFM vs Water Lift. Ed Valentine of Cross American Corp really developed the CFM theory. He also makes the best portable extractors in the US. www.crossamerican.com

 

[imported_smprince1]

I agree with what you guys are saying. One parameter without the other can give somewhat of a false idea of vacuuming effectiveness.



Water lift is the amount of negative pressure from atmospheric (or vacuum) a unit can develop at zero flow. Pure suction pressure but with a dead-ended hose.



CFM is the amount of volumetric air flow per minute that a unit can pull, or course at some set value of negative pressure.



It would be most useful to see the parameters combined, such as X amount of CFM at a Y pressure (water lift). For a given airflow, the unit can only maintain a certain amount of negative pressure (or vacuum).



I am not sure if the industry uses standard conditions when it lists these parameters. If not, the numbers can be manipulated.

 

[General Lee]

Whew! why do they (manufacturers) have to be so complicated