Originally Posted By: paul
by increasing pipe size the resistance is greatly lowered.


Yea sure, but it also lowers the rate of heat absorption/dumping per volume flow rate. That means you have to pump more water to get the same amount of cooling, and overcome a higher back-force from the bouyant hot water you're pushing in.

Maybe the reduced resistance compensates for that at any scale, but you can't be sure without actually calculating or testing it.

Quote:

and this surface tension causes turbulance to build inside the flow area.

I have to nit pick again, but the fluid clinging to the walls on its own is bad enough, even without turbulence. Many industrial pipe systems are designed to have laminar flow just so they can save power, but they still suffer the losses you mentioned.