Radiant Floors

Radiant floor heat is known for its superior comfort and energy efficiency. Radiant floors are popular in expensive homes in cold climates. The radiant floor’s large surface area warms the space by heat radiation. This radiant heat creates an environment where the human body feels comfortable at a lower air temperature because the floor and objects in the room have a higher temperature, compared to homes with forced-air heating. Comfort is created by a combination of

Radiant floor systems deliver heat to the home through either pipes or wires that are installed in or under the home’s floor. They warm the masonry slab or wood floor, allowing heat to radiate up into the home. The most popular system utilizes flexible plastic tubing filled with water that is heated by a natural-gas boiler. The tubing for this type of hydronic system is placed either within a concrete slab or under a wood floor system. The concrete-slab system is better than the wood-floor system. Attaching the tubing to a wood floor isn’t as efficient because the water must be heated to a higher temperature than water supplied to slabs.

Radiant heat systems are relatively expensive to install, and their installation requires a high degree of care. The pipes should all be tested for leaks before they are covered by the flooring materials. And the concrete slab should be insulated underneath and on its sides; otherwise heat conducts rapidly through the slab to the ground – an expensive problem that is impossible to fix.

The least common system is electric resistance radiant heat because they are very expensive to operate. One exception is electric radiant floors in bathrooms, which are common to provide superior comfort where comfort standards are high while helping to keep the bathroom floor dry.

See The Homeowners Handbook to Energy Efficiency or Residential Energy: Cost Savings and Comfort for Existing BuildingsChapter 6 for more information. For professional information about heating systems and energy efficiency see Saturn Hydronic Systems Field Guide.