apparent difference between fox and charnwood extractors

[miles_hot]

Looking at the Charnwood and Fox sites they appear to have the same extractor however there are pretty different flow rates being quoted. I suspect this is down to differences in the way that the flow is being measured - maybe the fox is measured with no filters (or the 35 micron filters) and the Charnwood with it's 5 micron filters - however I wondered if anyone else has any other ideas / knowledge, for instance is the impeller on the fox better in some way?

Charnwood W692
Power - 2200w
Flowrate - 3000 m/h (I assume this should be m3/h)
Filtration - 5 micro
Inlet dia - 150mm
wxdxh - 1500mmx750x1950
weight - 59Kg

fox
Power - 2200w
Flow rate - 3905m3/h
Filtration - 35 micron
Inlet dia - 150mm
wxdxh - 1500mmx750x1950
weight - 59Kg

Your thoughts would be very welcome as I plan to make one of these the centre of the new dust extraction system if some of my other plans come to nothing...

Miles

 

[OLD]

Finer filtration reduces the flow rate.

 

[miles_hot]

Finer filtration reduces the flow rate.

I figured this could be a contributing factor however I wondered if it would account for the nearly 1/3 difference...

Miles

 

[TheTiddles]

Finer filtration reduces the flow rate.

I figured this could be a contributing factor however I wondered if it would account for the nearly 1/3 difference...

Miles

I'm suprised it's that little!

Aidan

 

[lurker]

Contact charnwood & ask them
They are not rocket scientists but I've found them relatively honest & helpful