Quote Originally Posted by ranker View Post
I'm really curious on the effect of using a T-joint as an elbow. What I'm implying is that I'd like to connect a T directly to the radiator. The other end of the T will be capped off with a G1/4 temp probe. The branching T itself will be connected with tubing to continue on to the blocks.

I'm wondering if that sort of implementation of an "elbow" will result in a larger pressure drop.
The only thing I could relate that to without having done the test myself is some generalized engineering equivalencies to fitting losses. A more typical fitting loss pipe length equivalent is something like this:

Fitting vs Equivalent Pipe length
Elbow = 1.5'
T flow through = 1.0'
T branch = 3.8'

Unfortunately because most fittings have a smaller ID than hose fittings we actually experience higher pressure drops than those typical published PVC pipe type length equivalencies. For example I found one 1/2" Elbow is worth about 4' of 1/2" tubing....that's a 1/2" elbow meant for 1/2" hose that actually has an ID of about 3/8". If an elbow is worth 4' of tubing a T branch "could" be worth twice that much.

Now that sounds pretty bad....BUT tubing itself is not very restrictive so that doesn't tell the whole story.

If I have a more typical system that's getting 1.53 GPM for example and add 8' of tubing to it, I'd only reduce the flow rate down to about 1.45 which is some, but in terms of temperture not enough to worry about.

If possible though for absolute best efficiency, putting that probe on the 90 side of that T so flow passes straight through would be even better.