2.4: Electric Heat – General

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Page ID: 18027

Aaron Lee
BC Campus

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10 Electric Heat – General

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A BCcampus element has been excluded from this version of the text. You can view it online here: https://opentextbc.ca/basichvac/?p=48

There are several main styles of fixed electric heating loads, including baseboard heaters, unit heaters, heating cable sets (in-floor heating) and central electric heating, which is similar to central gas heat, in that there is one source that distributes heat, usually by blowing warmed air through ductwork.

Electric heating loads are very reliable methods of heating a building. By passing current through a resistive element, our electric heaters produce heat proportional to the square of the applied voltage.

$\text{P}=\dfrac{\text{E}^2}{\text{R}}$

This means that if you connect your heating load at half its rated voltage, you will produce one quarter of the power, or consequently if you connected at twice the loads rated voltage you would develop four times the rated power. It is for this reason that fixed electric heating loads are connected at 240V, which is the line-to-line voltage inside most houses.