I'm confused, Radiator Flow Rate, More not always better?

[Marci]

You'd probably need at least 4 sensors per fan and they would need to be permanently fixed in an outlet shroud of sorts to get any worthwhile air out data.

Getting towards standardised methods here...

That was exactly BillA's early testing methodology (iirc)... airflow and temperature measured at each quadrant (minimum) of the fan (if in a duct, using duct traverse method [Link 2] - which is what relttem's on about above - there's an industry standard set of guidelines and methods for doing such things - these should be referred to and adhered to wherever possible to ensure valid data. Bill tried to highlight the necessity to adhere to such guidelines for any airflow based testing, which also points out that you shouldn't test axial fans using a duct - they aren't designed for use in such scenarios - use an airchamber instead - you can see his 'hints' at this in the aftermath relating to Vapor's original fan review threads... comments were also made on folks doing noise testing of fans, which basically meant read this and this). BillA's data was used to produce the coolingmasters article if memory serves, before he got the windtunnel/envirochamber (which he acquired to counter the "small thing like someone walking into a room" effect)... about 6 months prior to doing the PA testing (by which point he DID Have the windtunnel / envirochamber).

Ultimately, if testing fans and airflow, either on a radiator or not on a radiator... reference this book
If working out resistance to airflow of a radiator (or anything else) have a read of this one for an idea of correct methods.

Info on temperature fields of radiators (uses domestic household radiators, but gives some good clues to what goes on within w/c radiators) here

And SUPERB info on radiator testing as used in aeronautics - old (as in 1920s) but still very relevant - HERE

I heartily recommend serious testers read all the above links and bookmark them for future reference... the closer folks get to using the standardised methods for everything, the more accurate the data you get... and if all testers follow the same standardised methods, using recommended standardised equipment, then data begins to become comparable across different testers.