Laguna 2HP DC...1600 or 1450 CFM?

[Derek Arita]

I recently purchased this DC based on research I'd done. All that research said that this DC produces 1600 CFM. I happened to be on the Laguna sight today and found that this DC is rated at 1450CFM. Being confused, I called Laguna and asked is it 1600 or 1450? The guy I spoke with at Laguna said, "I don't know." He said the manual for the DC says it's 1600, but the website says 1450. He said he would bring it up with someone.
Now I'm kinda bugged, since I did purchase this DC based on the 1600CFM rating. Had I know it was 1450CFM, if it is, I may not have chosen this DC. If it is 1600, I'm still kinda bugged, because Laguna doesn't even know what it's own DC is really rated at...not exactly a confidence builder.

[David Kumm]

Derek, there are no standardized ways that DC manufacturers measure CFM. You are likely being quoted free fan rating which is meaningless when the impeller is connected to pipe and filters. To get working cfm in the 1400-1600 range at the machine port you need a 5 hp 15-16" impeller system. A 2 hp will get you 500-750 cfm real world performance and I might be generous. Dave

[Derek Arita]

Thanks for the info...that makes sense. What about static pressure? I've seen both 11.0 and 14.5 for this unit. What does that mean?

[David Kumm]

The higher the SP number the lower the cfm. I would guess that a 2 hp 13-14" impeller with a backward inclined blade won't deliver much cfm at 11.5 " sp. 14.5 is more in the top range of a larger diameter unit. When comparing cfm among companies- and good luck believing the numbers- I look at cfm delivered at 8" to 14". Depends on lots of variables but with a cyclone 8" is probably is low as you can get so your working range starts there. Without a cyclone you gain about 2-3" but you may give some of it back due to less filter area vs a bigger system. Dave

[Derek Arita]

I know there is an error somewhere, but I really don't know who's error it is and which number is right. I have a feeling that the manual is correct in 1600CFM/11" Static Pressure, but that means that Laguna's own website has it wrong.
At any rate, it's disheartening that those numbers really don't mean a lot. I don't understand why there's no standard that we manufacturers can go by. I guess if they did that, then they'd have to play on a level playing field and I don't think any of them want that.
Wonder if anyone out there has done some real world testing on the DCs and produced some real numbers. A while back, someone was doing that, but he and his cohorts got embroiled in some kind of weird situation and that only clouded the info. Too bad, cause the info was helpful while it lasted. I think it even resulted in a really efficient, home built, reasonably priced, kit cyclone.
Not all of us are equipped to interpolate all the numbers and come up with meaningful info.So how do we do it? How do we get manufacturers to Man Up and give numbers that we can compare, as Joe and Mary Beercan consumers?