Putting the Pex in the trench.

The weather today was perfect for working with the PEX so we decided to get the tubing in the trench. We designed the Primary and Secondary hydronic loops with TACO's HSS program, and determined 1.25" PEX would supply sufficient BTUs to the house load, with minimal head loss, and reasonable cost per foot.

We used WIRSBO hePex, since the boiler manufacture requires Oxygen Barrier PEX for the installation. The 1.25" is a stiff to work with, so the 70F degree day we got on November 8th was perfect to warm the tubing up, and make it easier to uncoil and lay out.

Once we had the 2 pieces cut and marked as supply and return, we fished them through the conduit into the shed. I used a corrugated drain tube

to provide access into the shed for the PEX once the pad was poured.

We put 2" pink board foam insulation in between the supply and return tubes the entire length of the run. This was done to minimize parasitic heat loss between the supply and return water.