11 Baseboard Heat

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The simplest form of fixed electric heat is the baseboard heater. These small, modular units with their long horizontal profile are installed underneath windows and other areas of high ambient heat loss.

An example of a baseboard heater, both with the cover on, and with the heat fins and wiring connections exposed.

Energized at 240V in households to maximize heat production, baseboard heaters are commonly controlled by line-voltage thermostats installed in each room or heated area though some can also be controlled by built-in thermostats installed directly into the unit housing.

Two circuit diagrams, each with 2 lines and a 240 V fixed heating load. One has a 240V DPST thermostat. The other has a 240V SPST thermostat.
Control methods for 240V baseboard heaters.

Because line-voltage thermostats directly control the flow of current to the heater element they must be rated for whatever value of current flows through them.

Baseboard heaters are rated for their power output, in watts, and are generally available in 250W increments, thus allowing installers to select the appropriate size of heater for the area being heated. To find the current requirements of a device, divide the rated power by rated voltage.

For example, a thermostat rated 3kW at 240V would be able to handle 12.5 amps of current.

[latex]12.5\text{ A}=\dfrac{3000\text{ W}}{240\text{ V}}[/latex]

When installing any kind of baseboard heaters, care must be taken not to install any other electrical equipment above them. No receptacles may be installed above a baseboard heater because of the risk of a cord resting on the heater and getting damaged by the heat. If a receptacle is required in a section of wall that also has baseboard heat, some manufactures will provide spacing inside the heater for installation of a receptacle.



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