How much does a 90 really affect flow?

i'm so close to starting my completely copper wc project. i am going to use copper tubing because i'm putting it all in a microatx case. he he he yes will be interesting. i'm pretty sure with minor modification it will all fit. anyway, i will definately have to use a couple of 90 elbows in there. should i break my back to use as few as possible, say 2 45 elbows instead? i could probably eliminate some of them with that method. how restrictive is a 90 elbow. keep in mind that copper 90 elbows actually fit over the tubing, so the actual ID is slightly larger than the original tubing. advice please.

jungle

do you access to a tube bending maching so you dont have to use any joints?

Not a whole lot since your 90's ID is larger than the tubing ID, although you still want to have as few as possible.

90 Degree resistance

Some interesting reading can be found here . My best guess is 1 1/2 90 degree elbow would be about the equivalent of 2.5 feet of straight tubing run.

hmmm that doesnt seem too, too bad. like i said, this isnt going to be a real top end cooling system here because of space limitations mostly. i guess it would be beneficial to try to use as few 90's as possible. but knowing this i wont lose any sleep over one or two. thanks for the info.

jungle

my suggestion is to do large-radius bends in the copper tubing in place of 90º's, though you still may need some 90º's for tight bends

There is a flow restriction calculator out there, specifically for water cooling... Dunno if I saw it on procooling or here though =\

Believe its this:
http://www.pressure-drop.org/

But its down for me...

If you choose components that don't require high flow rates to work decently then you can avoid hours of aggrivation and planning in a vain attempt to eliminate all of the bends. An example is pin-fin type waterblocks; they are not the best but do work well at low flow rates (MCW-5000 family is a good choice). If you want the best cooling, it'll probably be a high-flow setup with the newest block(s). If decent cooling is acceptable then many more options such as lower flow, smaller diameter tubing, smaller/quieter pumps, etc. become acceptable options.

I am using an ehiem 1048, which is supposedly silent. I havent gotten a chance to try it yet. I would try large diameter bends, but i dont have the space, hence the need for 90's in the first place. I am only planning on cooling the cpu for starters, even though my new vid card that is coming in will have a fan on the gpu. thats for another day. i was kinda trying to hang around and see if i could get enough posts to get onto the classifieds, but doesnt look like thats gonna happen right now. i want to do this over xmas break here. anyway i'll probably pick up a low restriction cheap block somewhere, so flow won't be that big of an issue. i think ill start with just putting it together and proving i can fit it in the case, then maybe next gen. will be an upgrade.

jungle