Uponor Radiant Floor Heating Systems for the Home Uponor, formerly Wirsbo, was the first to bring radiant floor heating to North America more than 40 years ago. Today, Uponor radiant floor heating systems are bringing the energy-efficient luxury of radiant floor heating to the masses for a simple, affordable solution to home comfort. In an Uponor radiant floor heating system, warm water flows through flexible, durable crosslinked polyethylene (PEX) tubing that is embedded under the floor. The warmth radiates up from the floor to warm objects and people in a room. It is the purest form of human thermal comfort. Uponor Solutions: Commercial Radiant Heating and Cooling For more than 40 years, Uponor has been the standard by which all other radiant heating and cooling systems are measured. The first to bring radiant heating to North America, Uponor (formerly Wirsbo), is the leader in hydronic radiant system design and application. A hydronic radiant system consists of warm or cool water flowing through flexible PEX tubing embedded in the floor or in radiant panels. Radiant systems use the structure and surfaces of an area to transfer energy. In radiant heating applications, the energy moves away from the heated surface towards the cooler area; for radiant cooling, the energy moves towards the cooled surface from the warmer area.