Quote Originally Posted by MrBean View Post
Good post Stephen - that's the same formula we used to use when I studied (and passed) for my DipTech in Instrumentation and Controls in the 80's.

And representative of my experience too, although, as I have stated, in practice, I see very little to no appreciable improvement in temps running pumps at 4.3 LPM vs 7.5 LPM - this as measured by the Koolance flowmeter, flows might not be 100% accurate, but for the purposes of the experiment, close enough....
Yes it is usually difficult to measure. With some lab equipment you have a slightly better resolution for this type of things where differences are small.
In general radiators will yield any visible improvement from 1 to 2gpm for example. Depending on the water block you are running you may start seeing some performance degradation as flow rate drops.