RADIANT PANEL - BY DEFINITION
To be a true heating or cooling panel, the surface temperature of the panel must be controllable and not exceed 300°F. (Most panels operate under 150°F; floors generally less than 85°F.) It is only a "radiant" panel if 50% or more of the heat transfer is by radiant energy. You may be more familiar with terms like "radiant floor" or "radiant ceiling" heating, or "radiators". These are not to be confused with hot water or electric baseboard heaters which actually produce only a small percent of radiant energy and primarily heat air.
Where Radiant Panels are Located
A radiant panel can be effectively mounted on any flat surface. The only requirement is the surface be sufficiently large enough. The larger the surface, the lower the actual surface temperature required. A wall radiator may have a surface temperature of 180°F while an 81°F floor will do the same job. Radiant energy will heat the surfaces of all objects which are in direct line of sight from the panel; that means all walls, floors, ceilings, chairs, tables, or people which can be "seen" by the radiant panel. Therefore, a heated ceiling will raise the surface temperature of floors and walls, while heated floors will raise the temperature of ceilings and walls. Air coming in contact with these surfaces is also gently heated.
How Panels are Heated
Whether your choice is floor, wall or ceiling panels, they are heated in one of three ways: water pipes, electric elements or air channels embedded in the panel. Of these three, air is seldom used, leaving electric circuits and water pipes (or channels) as the most prevalent. Electric panels have electricity as their sole utility, are quite simple in construction and generally have a lower 'up-front' cost. Water, on the other hand, can be heated by almost any utility be it natural gas, propane, oil, wood, solar, or electricity, and is quite versatile. Your choice will probably hinge on the energy costs of the available utility and the size of the project.
Radiant Panel Construction
Panels come factory assembled or constructed on site. They can be surface mounted on floors, walls or ceilings or embedded. Wall and ceiling panels generally come pre-assembled and are primarily metal with a decorative surface. Floor panels are usually part of the floor construction. They consist of electric cable or warm water tubes embedded in or attached to the floor. The cable or tubes may be buried in a concrete slab, covered with concrete or gypsum on a wood subfloor, sandwiched between layers of a wood floor or attached beneath the subfloor. Often metal plates which act as fins to disperse the heat within the floor are used in wood floor applications. Radiant panels can be used effectively in combination with other forms of heat distribution including baseboard convectors and forced-air. For example a home may have a heated concrete floor on the lower level and forced-air on the upper level.
Radiant Panel Response Time
Response time often refers to the time it takes for the system raise the room temperature when the thermostat setting is increased. This is not an accurate definition of response time and can lead one to a false conclusion that radiant systems can be slower than other heating systems. Response time should be measured by the amount of time it takes to make the occupant "comfortable". See "Temperature and Radiant Systems". In some cases, radiant systems can have a faster response time than other forms of heating. As a rule, wall and ceiling panels have far less mass than floor panels and therefore respond quickly to changes in the room environment. This is particularly true when recovering from setting back a thermostat at night or when returning from vacation. Floor systems are very stable and maintain a uniform climate because the floor surface remains at a constant temperature.
Controlling a Radiant Heating System
A simple wall thermostat is generally all that is required. Working in the background may be an "weather sensitive control" which adjusts the panel temperature based on the outdoor temperature for increased comfort and economy. A big advantage is the option of a thermostat in every room. This provides additional comfort as well as energy savings because you can turn down those rooms that are not in use or that you prefer to have cooler. Keep in mind additional features like these also increase the cost just like adding power windows and locks to the sticker price of an automobile. But unlike automobile options, these comfort features will pay back in energy savings.
Click Here to contact our Solar and Radiant Division Manager, Bill Spezza for any special requirements, needs or any questions that you may have.
