Pre-insulated Wirsbo® hePEX™ features oxygen-barrier PEX pipe encased in polyethylene-foam insulation to meet ASHRAE 90.1-2013 energy-code requirements for hydronic piping and radiant heating/cooling applications. The piping is approved for direct burial in soil provided it is not exposed to groundwater. Uponor recommends adding 1/2 in of insulation to accommodate for foam compression in direct-burial applications. Uponor Wirsbo® hePEX™ Pre-Insulated Coil, 1/2 in Nominal, 1.81 in Outside Dia, 100 ft Coil Length, 80 psi Working, 200 deg F, Cross Linked Polyethylene, Domestic