Not to open this debate again as I am sure we've all had this discussion before nor am I trying to hijack this thread (apologizing in advanced Caddi) but wouldn't a bigger tube move more water than a smaller tube? Of course the pump plays a roll but lets say for example, the 35x will need to pump more because its a bigger hose. A water pump needs to work more to push more. Wouldn't there be an increase of water mass if you will? I mean say an inch of tube filled with water from end to end. Won't it have more "heat absorbing properties" (if that makes sense) to pick up the heat than say the smaller tube with less water? I understand the effects of equilibrium but maybe if the heat surface is compensated enough for the amount of water used for example. How would we calculate the properties of the said amount of water with the said amount heat surface needed. I know most if not majority will say well, once the loop reaches equilibrium it won't matter. I mean if there was a way to calculate the amount of fluid used per square inch for example. Kind of like saying well, lets take a 120.9 for example. A thicker tube vs say a much smaller ID, one might get a few degrees improvements, no? I am not trying to state there will be a huge increase in performance or efficiency but maybe say 0.5-3c.
The reason I am saying this is and by all means I am no chemist or anything but it makes me think since I know there's a limitation. Is it safe to say the limitation of water is when it boils before it evaporates? So the water would have to reach that high for it to hit a wall if you will. Am I saying this right or am I not making any sense? Its A.M. and this insomniac needs some sleep.
Here's another example, from my "arm chair" understanding. Firefighters show up to a blaze. They will use bigger lines from 1.5" to 3" for say a big fire all the way to 5"+ up top on a tower/ladder apparatus etc. They need the most water (cooling properties) to cool the fire down. The 1.5" won't really do the job if its a blaze but the 3"+ will bring much needed cooling.
I don't know maybe that was a bad example or I am speaking gibberish in general. I think I am doing circles here and searching for something that doesn't exist. I'll be back later once I get some needed sleep.