radiant heating basics

Types of radiant heating

There are two types of radiant heating systems: radiant floor heating and radiant panel heating (based on panels used in walls and ceilings).

We may also consider:

1- Hot water (hydronic) under floor heating: by far the most popular and the most environmentally-friendly solution.
2 - Radiant electric floor heating;
3 - Radiant air floor heating, based on hot air: a rather marginal system, rarely used.

Hydronic/Water Radiant floor heating

Hydronic radiant floor heating relies upon hot water driven through tubing installed in the subfloor. This system demands some key elements:

- A water heating system (which may be a solar powered system, a geothermal heat pump or a standard boiler);

- A set of controls (thermostats...) and pumps to driven the hot water through tubing installed in the subfloor and to driven the water back to the boiler to be reheated.

See, for details: Hydronic hot water Radiant Floor heating

Image credit: American Hardwood Information Center

Electric radiant floor heating         

Electric radiant floors use electric cables inserted into the floor or mats of electrically conductive plastic mounted onto the sub-floor (below tile, stone, marble, laminate or engineered wood surfaces).

Since electricity tends to be expensive, hydronic radiant floor is a much popular and environmental solution than electric radiant.

See: Radiant electric floor heating

Radiant Panel Heating

Radiant heating may be obtained via wall and ceiling-mounted panels, usually electrically heated.

See: Radiant panels heating

Radiant heating & energy source

Radiant heating can use standard gas, electricity and other traditional sources of energy; and it can use environmentally-friendly sources as solar water heaters and geothermal heat pumps.

Air-Heated Radiant Floors

It’s possible to use hot air to heat the floor. But since air cannot hold large amounts of heat, these systems are seldom installed in residential buildings. Air-heated radiant floors can be used in conjunction with solar air solutions, but even in this case the system is clearly disadvantageous.

Ceramic tile, wood and other floor coverings

Ceramic tile is the most common covering in radiant floor heating. It provides an easy conduction of the heat and allows a lasting and stable heating, due to the ceramic good thermal storage properties.

Other common types of coverings include stone, vinyl, carpeting or hardwood and engineered wood surfaces, but some of them will decrease the efficiency of the system.

See, for details: Ceramic, wood and other radiant heating floor coverings

Prices

Hydronic radiant floor heating systems aren’t exactly cheap solutions. Electric radiant systems and radiant panels are much cheaper solutions.

See: Radiant Systems Prices and Costs

Manufacturers

Warmboard, Roth, Rehau, Wirsbo (now Uponor), Zurn or Watts are well known radiant manufacturers. But there are many others.

See: Radiant heating manufacturers

Pros of Radiant Floor Systems

Radiant heating floor systems provide extremely high comfort. Heat is evenly distributed, and the very fact that the heat source is at the floor level, close to our bodies, contributes to that extra-comfort.

Because no energy is lost through ducts, radiant floor heating is a very energy efficient system, comparatively to baseboard heating or forced-air heating.

Environmentally, radiant floor heating is a sound option, namely when associated with solar water systems.

Cons of radiant floor heating

Radiant heating is an expensive solution, with a limited interest in many climates or in well insulated homes. Besides, it doesn't offer cooling, contrary to other heating systems.

See: Radiant Heating Systems and Environment

Radiant heating and Thermostats

See:Thermostats and heating systems: furnaces, radiant heating...