PEX in electric conduit to barn.


Old 05-12-09, 10:27 AM
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PEX in electric conduit to barn.

I’m running a 50 ft water line to my barn. I would appreciate some advice on my proposed details:

Can I use PEX buried underground in grey PVC (electrical) conduit? Would white sched40 PVC be better?
I was thinking of using ½” PEX to feed two sinks. Is it enough?
I was planning to use 1 ¼ conduit. Will I then be able to pull the PEX through, in case I need to replace it someday? (there will be 5, 45 degree 9” radius bends in the line)
Trench depth is 24”
Since the trench is open, I was also thinking of running a second line for hot water, just in case I decide to provide hot water sometime later. Will the hot water make to the barn inside a 50ft ½” PEX inside a 1 ¼” PVC, or will the heat losses be too great?

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Old 05-12-09, 03:02 PM
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50' of 1/2" pex will be to small to give you any decent pressure. i would say run a minimum of 3/4" and preferably 1".

what all are you going to have water to?

if the hot will be just for a sink you would be better off just installing a small 120 volt 6 gal. wateer heater . they are small enough to fit in a sink cabinet or if you need enough for a shower a 20 gal. heater would be needed. the heat loss would be to great to run 50' under ground although you would get hot water eventually the energy costs would out weigh installing a seperate heater if you have gas or electric to the barn.
Old 05-20-09, 11:12 PM
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How it all turned out:

This project started by planning to take electricity (a 20amp circuit) from my house to my barn. Then I said: “Since I’m going through the trouble of digging the trench, why not also run a phone/network cable… then why not water for a sink someday… then why not warm water for the future and so….

I ended up running four 1 1/4” conduits to my barn. One for electric, one for phone/cable/network and two for water (cold/hot)

I ran two 3/4“ PEX water lines inside two of the conduits. The ½ PEX line would have gone in easily but the ¾” was a different story. I had to both push on one end and pull from the other. I suspect that the only reason I was able to finally do it is because I only used 45degree elbows (5 elbows on each conduit run). Had I used 90 degree elbows, ½” PEX may have been the only realistic option.

I also had to construct an insert to put in front of the PEX in order to push/pull it, to prevent the PEX edges from catching at the PVC conduit joints. It was a rather fallic looking insert made from a wooden dowel, shaped on a grinding wheel and a metal edge to reduce friction. I do not know if they make something commercially for this purpose. I immagine it’s a common problem.
Also, I don’t know if there is something to lubricate the PEX to help out, but I did not use anything and certainly stayed away from oils as they do degrade most plastics (including PEX?).

If I had to do it again, I would have skipped the conduit and burried the PEX directly, in spite of the PEX manufacturer’s advice to avoid burying the PEX in clay soils (my type of soil). I had to tunell under concrete for 3 ft so opening a small hole for the ¾ PEX would have been much easier than opening a 1 ½” hole in the dirt for the 1 ¼” conduit. The cost of the conduit is not much (around $30 for 50ft run) but it does take considerable amount of time to assemble it correctly in the trench and tunel it under the concrete.

I am not sure how I will handle the hot water if I ever hook up this water supply. I may try out to see how hot remains the water once it reaches the barn and if the results are not satisfactory I may install a small electric water heater now that I have also run conduit for electric. I guess, if I end up not using the second PEX line for hot water, I could then turn it into a second cold water line to increase my max water flow.

Running the actual electrical cables to the barn is still pending, subject to resolution of some grounding issues (I have an active post in the electrical forum).

Thanks for the advice.
Old 05-23-09, 10:57 PM
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Sounds like it all worked out for you in your situation. Just make sure you are covering the ends of that pipe at the barn. Exposure to UV rays on that piping ruins it very quickly.

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