# Need help with drip system - calculations (math time) :)

I know it's out there but I'm pressed for time and too lazy to go looking for it. :)
Here's what I need.
I'm running a drip system from the faucet in my garage to a second story balcony. My genius builder didn't think to install a faucet out there. Anyway, what I have is some 1/4" tubing that goes directly from the faucet (on a timer) up the length of the garage door, across the length of the garage door, down the length of the garage door (two car garage), out the garage to a patch of dirt, up a tree that brushes against my condo, exteneded along a branch, finally entering my balcony, up two a flower bed - whew......okay...Now, I have enough pressure to water two flowerbeds - 4 drip sprinklers. I want to add three more pots and know that i won't have the water pressure to do so.
The total distance that the tubing covers is around 50'-60'.
I have issues here with the homeowners association so I have to keep things as stealth as possible - that's why I chose to use the 1/4" instead of 1/2".
Soooooo...now I was thinking of re-tubing the lengths on the inside of the garage - up, across, and down with the 1/2" tubing. Is this going to give me more pressure?
I guess what I'm looking for here is someone kind enough to help me with some calculations.
Something like:
"water pressure" is directly proportional to "x length of tubing" having an "inside diameter of x"
I'd like to know if I gain anything by "cutting down" the distance that I'm using the 1/4" tubing and instead replacing it with the 1/2" tubing. The total length of all tubing with still be the same - still 50'-60'.
Say for example I now have:
A. 50 feet of 1/4" tubing from water source to flower bed and that I get a water presure reading of X.
B. If I use 20' feet of 1/2" and 30' of 1/4" should my water pressure increase? If so, by how much?
One more question:
C. If I use 20' feet of 1/2" then go to a 1' section of 1/4" then back to 29' feet of 1/2" would I have the same pressure as above in "B"?
Thanks... :)
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12:25:48 -0700:

Here's a site that might help: http://www.efunda.com/formulae/fluids/calc_pipe_friction.cfm
You might also want to post your question to a more technical newsgroup such as sci.physics or sci.math.

If you measure pressure with a device that halts the water flow, the result will depend only on the height of the measurement point, not on what kind of tubing you use. I suspect you're interested in increasing the flow rate.
energy/mass = v^2/2 + h*g + friction
Friction is proportional to the fluid velocity multiplied by the tubing area (length * diameter * pi), I think.
I don't think you'd do much better by replacing only half of it. Replacing almost all of it probably would help. Those are guesses on my part.
Can you set the timer to stay on longer?
-- spud_demon -at- thundermaker.net The above may not (yet) represent the opinions of my employer.
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