Ok, I've heard a lot of people say elbow fittings cut down on cooling performance, but are they really that bad? Some make it sound like its a carnal sin to use elbow fittings in your loop, yet I still see numerous builds with them, even when space is not a concern. Now I realize that in some cases, 90° elbows are unavoidable to keep the tubing from kinking in tight places, as in SFF. But in those instances, are people making a huge sacrifice in performance due to the lack of space? I'm wondering if there has been any definitive tests done that actually prove elbows diminish flow by x amount. Anyone with experience on this?
Hardly, if you use a good pump I doubt you'd even notice, people seem to blow it out of all proportion in order to sound "1337" to W/C Newbies.
Tables are available for the fittings used in central heating that should give you a good idea. A 10mm compression elbow is equivalent in flow resistance to 330mm of 10mm pipe; I imagine barbed fittings, by reducing the pipe inside diameter, are worse. A suitable pump will work, but it adds to system noise.
like cpemma said I'd be more worried about reducers ie from 3/8" to 1/4" if you can avoid elbow then avoid them, if you can't then you can't
