The impact of tubing sizes

[ranker]

Perhaps you might want to re-read the first post and take a gander at the pretty pics. Actually he sees the sweet spot at 5/16" (8mm) ID because the 5/16" with a push-fit has essentially the same graph as a 3/8" with a hose barb. And in actuality the difference between the worst and the best is only a measly 1.11 C. I don't think a 1.11 C difference is going to change much in the real world.

Kaaa aaa kkkks

Don't try to lie about he stated:

3/8" ID | 1/2" OD into 1/2" ID push-fittings is ideal

Those are his exact words. He sees 3/8" as the sweet spot and only to use 5/16" when you must for bends.

You may not value 1C, nor performance (which is obvious from your full Aqua Computer build), but most of us over here in XS are performance oriented. Many would pay a lot more for that extra 1.11C performance benefit. There's a reason why many of us jumped from 3/8 to 1/2 a few years ago and that was due to the 1.0C gain seen at the time. So yes, 1C is a big jump, which is why most of the WC'ing enthusiasts (people here at XS) purchase thermochill, Laing, Swiftech, D-Tek, etc products.

3/8" tubing itself results in minor .01C performance loss over 1/2" tubing, hence most of us won't mind dropping in size. However, low flow system, irrespective of tubing size, will perform worse. Low flow does not perform as well as high flow. You're using his data as a rallying cry for low flow systems as seen in your other posts; trying to misinform others by applying the 3/8" inch findings towards low flow setups in general.

How about you also stop trying to apply the tubing size findings to restriction overall. Elbows add restriction which hurts performance. More restriction leads to worse temps: http://www.xtremesystems.org/forums/...1&postcount=36

(sigh)

I'll pull out ye olde racetrack analogy.

If I'm a molecule of water, circulating around a water-cooling loop, I'm just going around and around and around. It's just like being a race-car on a race-track at a fixed speed. The time I take to travel through the radiator is like the time spent travelling down the main straight of the race-track.

If the race-track is 5 miles long, of which the main-straight (radiator) is 1 mile long, in the space of 1 hour, how much time per hour do I spend on the main-straight if I'm travelling at a fixed speed of 60mph, 120mph, or 180mph?

The answer is that the speed doesn't matter of course. I spent 1/5th of my time on the main straight. 'cos the straight is 1 mile long out of 5. Even if I travel at twice the speed around the circuit, it'll take me half the time to get from the start to the end of the main straight, but because I'm going twice as fast everywhere else, I'll be on the main-straight twice as often. i.e. No matter how fast I travel, I'll be on the main-straight for 12 minutes out of every hour.

Now common physics tells us that the rate of heat-exchange is proportional to the temperature difference between an object, and something else that's cooler than the object. If I'm a molecule of water, and air is cooling me (by way of the air cooling the metal tubes inside the radiator that I'm flowing through), then the longer I spend in the radiator, the cooler I will get (that's good), BUT, the cooler and closer I get to the air-temperature, the less quickly I'll lose heat (that's bad). The two cancel each other out. So why does higher flow results in better performance?

The more quickly I rush around, the more likely I'm going to be tumbled about (think white-water rapids as opposed to a smooth slowly flowing river). This means that I'm going to get tossed against the cool metal walls of the radiator more often, rather than just cruising along down the middle of the tube, only passing heat slowly to water molecules beside me that are only a little cooler than I, because they are beside another molecule, and then beside another molecule, before we get to the cold metal wall. i.e. water sucks for transferring heat if it's not getting mixed about and thrown against the cold walls.

Hope that explains it in a "simple" manner that is intuitive, obvious, and directly counters the "slower flow is better" argument.

You want as much flow as possible to dissipate heat better within the radiator.