Nothing says comfort like the feel of a warm floor beneath your feet. Uponor (formerly Wirsbo) radiant floor heating systems offer an affordable and energy efficient solution to heating your home. Warm water flowing through flexible and durable polyethylene (PEX) tubing embedded under the floor radiates warmth up from the floor to effectively heat the objects and people in the room. Typically, the heat source is a boiler or hot water heater. The PEX tubing transports the warm water to specific rooms, or "zones". This allows the temperature for each room, or "zone", to be changed according to its use.