Hydronic heating, the practice of pumping heated liquid through pipes in floors and walls to heat a home, can be a very energy-efficient heating system. The liquid inside the sealed system loses heat much slower than the air in a forced-air system, providing more warmth for less energy.
In a hydronic system, water or a thermal liquid is heated in a central boiler before flowing through a series of flexible pipes arranged throughout the house. Typically, these pipes flow under floors to take advantage of the fact that heat rises. The warm liquid transfers heat to the entire floor of a room, which then radiates that heat upward. As the liquid loses heat, it is recirculated for reheating. A hydronic system may take a little extra time to warm a room completely, but once the system reaches its operating temperature, it can maintain that temperature without using very much energy.
The efficiency of a hydronic system depends on a number of variables. A gas boiler is usually more efficient than electric heat, since electric heating relies on resistance losses to create warmth. A layer of under-floor insulation also helps direct heat upwards into living spaces, reducing the amount of heat lost and keeping the family comfortable at lower temperatures.