Radiant heating panels are panels that can be used in the walls or ceiling of a structure, whether residential or commercial, to provide heat to a room. A range of options is available, from solar-energy supplied panels to gas- or electric-supplied panels, to panels that use hot water to provide their heat. What makes them unique is how the heat is distributed in the space the panel occupies.
Conventional heating systems, such as a central furnace, heat the air. This air is then circulated to warm a space. Such systems are affected by airflow and the location of outlets. For instance, the venting outlets for a traditional furnace are ideally placed at floor level so the warm air they bring to the room will travel upward, passing warmth to the surrounding air as it rises, and heat will be evenly distributed. A system that uses a central furnace also requires fans to circulate the heated air.
Even systems that use liquid boilers and pipes to distribute heat operate on similar principles. While such systems — which heat liquid at a central location and circulate it through pipes to heat a structure — do not use an active means of circulating air such as fans, they do rely on the movement of air created by heating it to evenly warm a room. For this reason, the portion of the system that extends into a space to receive the transfer of heat is always near the floor. That way, as it warms the surrounding air, the warm air will rise and new, cooler air will move in to be heated.
Radiant heating panels, in contrast, warm occupants of a space in the same way that the sun warms a person on a cold day. While the surrounding air is quite cold, direct exposure to sunlight may still make a person feel warm. This is the effect of radiant heat, — actually electromagnetic waves like those of which light is made — passing energy to things with which they come into contact. In the case of a person, this energy is experienced as warmth.
Radiant heating panels create electromagnetic waves that are similar to sunlight but invisible to the human eye. They convey energy directly, just as the sun does, so their location in a space is less important. Radiant heating panels can be placed on a wall or ceiling and will heat the occupants of a room just as well, regardless.
Radiant heating panels do not use the surrounding air to pass warmth to the occupants of a space, so they are ideal for outdoor spaces. Through the use of radiant heat, occupants of a space around the panel can be warmed to a comfortable temperature that is much higher than that of the surrounding air. Radiant heating panels heat the occupants directly, like the sun or a campfire, and so can heat people without warming the air.
The biggest drawback to radiant heating panels is that they warm by line of sight. This means that, like the sun or a fire, the part of a person closest to the panel will be the warmest. If there is an object such as a chair in the space, standing between the chair and the heater will allow a person to be significantly warmer than if standing with the chair between the person and the panel.
Radiant floor heating sounds similar to radiant heating panels for the walls or ceiling, but there are differences. While both use radiant heat, radiant floor heating is more closely related to the boiler and piping system than to the radiant wall and ceiling panels. The floor heating system continues to rely on airflow, in addition to radiant heat, to evenly warm a space.