2.1 Electric Radiant Panel Overview

Electric radiant heating panel is defined as a flat surface from which at least 50 percent of energy transfer is accomplished through radiation from the electrically powered panel. The source of the energy that produces heat radiation from the panel surface is the product of electric geothermal, or resistance heat, processes. Electric geothermal heat pumps extend the option of electric radiant heating and cooling to hydronic design.

Electric radiant heating panels include concealed and visible panels that cover or encompass a large or small fraction of a wall, floor, or ceiling. Panel form includes discrete surface-mounted, recessed, or suspended ceiling units; recessed or surface-mounted wall units; embedded floor, ceiling, or wall cables, wire, and mats; and hydronic tubing circulating an electrically heated or earth- or evaporative-cooled fluid.

Electric radiant heating panels are used in residential, commercial, institutional, and industrial buildings. Most electric radiant heaters in the United States are available in 120, 208, and 240 V. Some types are available in commercial voltages of 277 and 480 V. To maintain rated wattage output, electric heaters must be operated at nameplate voltage. Foreign voltages, which are often different, would require products designed to operate at the specific voltage specified.

Electric radiant heating panels and/or their components are subjected to a series of specific safety tests, procedures, and inspections by recognized testing agencies, and sometimes are required under national, local, or foreign electrical codes. Components and connection wire may have stamped or printed certification or listing marks. Discrete or modular panels have listing or certification nameplate or labels showing wattage output at rated nameplate voltage.

International use requires voltage design for 100-, 200-, 220-, and 347-V applications. However, voltage fluctuation can be very wide in some countries.Transformer devices are used to stabilize voltage to improve performance consistency and prevent equipment damage. Evaluation of power reliability, consistency, and quality are important to the development of equipment and control design and selection.

Unlike nameplate wattage ratings on office equipment and some appliances, the actual wattage output normally is within a range of between +5 percent and −10 percent of nameplate rating in conformance to the listing or certification. (See Fig. 2.1.) Field wattage verification is made through the application of Ohm’s law by using an ohmmeter to obtain the panel electrical circuit resistance rating.

An understanding of basic electrical principles is essential to converting the radiant system design load to an electric radiant panel installation circuit and control layout. Once the designer has determined the Btu requirements, the conversion to wattage will enable determination of amperage required, which will determine circuit design.There are control options to serve whatever electrical circuit is designed. In general, single 20-A circuits are often served by in-line controls, and larger loads and complexes are often served with low-voltage or energy management system (EMS) controls.

2.1 Electric Radiant Panel Overview

Electric radiant heating panel is defined as a flat surface from which at least 50 percent of energy transfer is accomplished through radiation from the electrically powered panel. The source of the energy that produces heat radiation from the panel surface is the product of electric geothermal, or resistance heat, processes. Electric geothermal heat pumps extend the option of electric radiant heating and cooling to hydronic design.

Electric radiant heating panels include concealed and visible panels that cover or encompass a large or small fraction of a wall, floor, or ceiling. Panel form includes discrete surface-mounted, recessed, or suspended ceiling units; recessed or surface-mounted wall units; embedded floor, ceiling, or wall cables, wire, and mats; and hydronic tubing circulating an electrically heated or earth- or evaporative-cooled fluid.

Electric radiant heating panels are used in residential, commercial, institutional, and industrial buildings. Most electric radiant heaters in the United States are available in 120, 208, and 240 V. Some types are available in commercial voltages of 277 and 480 V. To maintain rated wattage output, electric heaters must be operated at nameplate voltage. Foreign voltages, which are often different, would require products designed to operate at the specific voltage specified.

Electric radiant heating panels and/or their components are subjected to a series of...