CFC copper tube size

I see that most of the CFC DIY use 25' 3/8" copper tubing. What about using 1/4" tubing? I am in a hot environment, and tap water doesn't get much below 80F in the summer, so my thoughts were smaller diameter tubing to increase the surface area to volume ratio, and use this for 50'

Besides, its $35 for 50' of 1/4" and $75 for 3/8"... I'm cheap....

My fluid dynamics is a little rusty, but I know the decreased diameter and increased length will decrease flow rate due to increased resistance, and the decreased diameter and flow will in turn lower the Reynolds number, leading to laminar flow. I know turbulent flow is desired, but I guess my questions are:

1. Am I missing something stupid and should stop thinking cheap
2. will the decrease in flow/increased surface area counteract the heat transfer limitations with laminar flow
3. if flow is a huge deal, what about running two 25' sections in parallel through the same hose
4. With a good filter in the boil pot, plugging shouldn't be an issue with a smaller diameter tubing. Right?

Seems like the answer to 2) would be tough to figure out, since there's a temp gradient along the length of the CFC (and therefore a viscosity and specific weight gradient)... and I guess you need to know those things if you care about ensuring turbulent flow.

I'd think about it some more but my girlfriend insists on going to bed or something.

:rockin:

Look at it this way; You can't speed up the flow through a restrictive diameter but you can slow down flow on a larger one. I can tell you that a gravity drain though even 3/8" OD x 25' is pretty slow already. You don't need 50', it's overkill.

I have to run really slow when the tap is 70+. When it's 55F in the winter, I actually have to restrict my tap flow or wort comes out at 60F.