Radiant Heat Options

The Basics

• A radiant system works by running heat underneath the floor. It uses thermal radiation to warm up the floor and anything else it touches, including you, by not wasting rising heat like a standard system does. This is not a new concept--the ancient Romans utilized radiant heat by running ducts underneath their floors and warming them with air fueled by fires burning beneath their buildings. While today's systems might seem more complex, the idea is the same--keeping people consistently warm.

Electric Radiant Systems

• The easier, less expensive and least efficient way to bring radiant heat into your home is by installing electric radiant flooring in a bathroom or other tiled room. This system, which uses loops of resistance wire powered by a 15- to 20-amp circuit, will require you to tear up your existing floor, lay electric mats, and then install a new floor, writes Tim Snyder in "This Old House" Magazine. It will also keep your feet warm when you climb out of the shower in the morning, while using minimal amounts of electricity. A typical bathroom-sized remodel costs between $400 and $700, as of 2011.

Hydronic Installation

• Hydronic radiant heating systems, which are by far the most popular, are typically installed throughout a house, or at least on the main level. Due to their complexity, only a plumber with hydronic experience should install these systems.

  Hydronic systems warm the floor by pumping water through plastic tubing that is typically heated by a boiler or hot water heater. The tubing can be laid in concrete when applicable, but it is only rated for tile, vinyl and linoleum floor coverings. A hydronic system can also be installed directly below the subfloor or nestled between the joists, in which case a hardwood floor can be laid on top of it. Snyder writes that the installation cost is typically $6 to $12 a square foot, which is two to three times the cost of most heating systems. However, you can cut your heating costs by approximately one third.

What to Look For

• Whether you are purchasing a home with an existing hydronic radiant system or looking for a plumber to install a new one, make sure that the system has multiple heating zones with thermostats that will allow you to conserve money and keep the house at an optimum temperature. Another positive feature of a hydronic radiant system is that it comes with an outdoor reset control that adjusts the amount of hot water passing through the tubing, based on the outdoor temperature. Finally, make sure that specially treated polyethylene tubes are used to carry the hot water. These tubes do not corrode like copper. They also don't have as many fittings, which reduces the chance of leaks.