Trunk insulation. Foil backing on two inch fiberglass. Check Menards. Kind of like what you'd wrap a water heater in. Not weather proof by any means so I would assume you'd run it in pvc or draintile.
it needs to be closed cell foam to be very effective. Once fiberglass is full of ground water or compressed it is not much R value. It only insulates by the air in it. The insulated and plastic covered pipe with one or more pex lines inside are hard to beat for insulation value and convenience but are a bit pricey.
I have a very short run and used a product similiar to this.
I fear no heat loss..
It doesnt have any insulation between feed and return so you lose efficiency with lower water temperature at your radiators and the return temperature is higher so you lose some efficiency at the boiler end too. If you can keep the insulation from sucking up groundwater it will work but will use more wood. If the wood is cheap not a big deal but if you are paying top dollar buying wood it likely would pay to go the better pipe.
This is correct. One the fiberglass gets wet, it is junk. SOLID drain tile is required for this method, and take care to seal the ends so as to prevent water from entering. Ideally the foamed PEX with the plastic liner is certainly best. At $13 a foot, I'll take my chances with something else. If I'm wrong, I'll burn a little more wod and try something different next year.
Why not do it right the first time and be done with it?If what you use dose'nt work,you have that money plus the money for the good stuff added together plus tearing up the yard again and having to pay for the second excavation as well.You know that you shopped around and priced and looked at different models of boilers until you made the choice that was right for you,why would you shortchange yourself at the end of the process?