Dan Friedrichs
02-15-2011, 10:41 PM
I'm building a mini cyclone for my shop vac, and was concerned that it seemed I was getting less "suck" than I expected. So I wanted to come up with a way to measure my shop vac's performance, with and without the cyclone.
I know nothing of fluid dynamics. Is it accurate to say that static pressure is the most reasonable measurement of a shop vac's performance? I don't need to measure CFM's? (I do understand that different shop vacs are designed with different fans that achieve different SP vs CFM, but presuming I am simply looking for a way to evaluate whether or not the addition of a mini-cyclone has significantly decreased my suction, is a measurement of SP sufficient?)
In that case, can I measure static pressure by nailing a piece of clear tubing to a tall board, putting a jar of water at the bottom, connecting the top end of the tube to the shop vac, and turning it on?
Well, I hope that works, because that's what I did. I found that my Rigid blower/vac produced 43" of water using an old CleanStream Pro filter that has been used so much that it won't even rinse clean any more - it's brown.
Figuring that perhaps I could do better with a new filter, I bought a new CleanStream Pro filter, and found that it only produced 44" of water! Only 1" improvement from a dirty year-old filter to a brand new one.
So:
1) Is my test valid? Am I taking the measurement correctly?
2) Has anyone else experienced such a long life of their CleanStream filter? Are these things supposed to be replaced after a certain amount of time?
I know nothing of fluid dynamics. Is it accurate to say that static pressure is the most reasonable measurement of a shop vac's performance? I don't need to measure CFM's? (I do understand that different shop vacs are designed with different fans that achieve different SP vs CFM, but presuming I am simply looking for a way to evaluate whether or not the addition of a mini-cyclone has significantly decreased my suction, is a measurement of SP sufficient?)
In that case, can I measure static pressure by nailing a piece of clear tubing to a tall board, putting a jar of water at the bottom, connecting the top end of the tube to the shop vac, and turning it on?
Well, I hope that works, because that's what I did. I found that my Rigid blower/vac produced 43" of water using an old CleanStream Pro filter that has been used so much that it won't even rinse clean any more - it's brown.
Figuring that perhaps I could do better with a new filter, I bought a new CleanStream Pro filter, and found that it only produced 44" of water! Only 1" improvement from a dirty year-old filter to a brand new one.
So:
1) Is my test valid? Am I taking the measurement correctly?
2) Has anyone else experienced such a long life of their CleanStream filter? Are these things supposed to be replaced after a certain amount of time?