Additional insulation when installing OWB water lines in the ground

[dparkguy]

Step one of my OWB install arrived the other day. 200' of 5 wrap PEX-AL-PEX pipe. I may be over thinking the install of the pipe but want to make sure I have tried everything to get the best heat transfer from the OWB to my house. I was thinking of using 1 1/2" polystyrene cut 6" wide and laying it on the bottom of my trench followed by 1/2" on the sides of the pipe and cap it with 1 1/2" making a box around the pipe then covering it with 6" of fine quarry "screenings". My second thought was to pull the lines and insulation out of the corrugated pipe and install an additional 5 wraps of closed cell foam. I plan on burying the lines between 28"-32" below grade. As many people have stated before...."Do it right to first time". I don't want to have to redo this or see a 6" wide strip of green grass after a snow storm. Am I on the right track?

 

[Jon B.]

I would - and did - use the Thermo-PEX. If you get any groundwater inside the insulation, it's gonna suck heat out'a the water quickly.

Thermo-PEX isn't cheap but it's water-tight and well insulated.

Jon

 

[rancher2]

I buried four one inch pex lines 360 feet and had them spray foamed five years ago and have had no problem with heat loss. I think if you might have a problem with ground water spray foam is the way to go.