Radiant floor heating systems work by circulating hot water through plastic or rubber tubing installed in or under floors to heat the mass of floors, furniture, and people. While the technology has improved since ancient Roman bath houses, radiant floor systems are still more expensive to install than forced air systems at an average of $5-7.50 per square foot. However, they use 15-30% less energy to heat homes evenly without rising hot air. Proper design and installation without leaks is key for an efficient and dependable radiant floor heating system.