Sorry, I should have stated that I am using hard tubing.Assuming you're going with soft tubing...
Some of the less commonly used tubing sizes can be harder to get hold of and it can be harder to get through tight bends without kinks/folding.
More info on what you're planning on doing and what your concerns are would be helpful.
Thanks for the reply.Largely aesthetics. Smaller diameter tube can usually have tighter radius's when bending also if that is important. So to an extent, if you have a large ATX Case / build, large tubing can work fine while in a very tight mini-iTX can be harder to work with. Also make sure the tubing size you get has a wide range of fittings available also.
Depending on what you read up, can be a small impact to flow / cooling, but reality is between the common sizes your likely to go, not going to make a massive difference in most builds.

I’ve used 12mm before and on my last build I’ve used 14mm. I’ve found 14mm easier to handle and bend into the shapes you need way better than the 12mm as it’s wall thickness is a bit smaller, you will get a bit more flow with high diameter tubes but I would say that it is a negligible small increase. 12mm is way better for small cases as the radius of the bends are smaller and easier to deal with small spaces.
Thanks for the video, just watched it and got it. Most of the fittings have the inside diameter way smaller than the tube diameter so if you get bigger tubes most of the fittings will restrict your flow so you don’t really get more flow, just really for aestheticsYou don't. Not from what Dazmode has tested. Bigger size is only aesthetics.
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