If a resistor has a power rating of 1W, then we should not feed more than 1W to the resistor. Power dissipated by a resistor is P = I^2 x R or P= V^2/R both derivations of P = I x V and of V= I x R (Ohm’s law). I dissipate the heat with a 12V PC fan . I hooked them up this way though, the resistors in series, and they barely heat up, so I must not know how these things work even though I thought I did. https://electrical-engineering-portal.com/resistive-heating-explained-in-details The electric company bills not for power but for energy, using units of kilowatt-hours. Some resistors are sensitive to heat and light and vary their resistance in accordance with temperature or brightness. A resistors power dissipation must be further reduced if it's effected by near by components or resistors that are radiating heat which would effect the surrounding ambient temperature [of the resistor being effected]. Transferring heat energy generated by power resistors. Related Resources value. The above list is an extensive list of the types of resistors which exist today. In some cases, however, Joule heating is exploited as a source of heat, such as in a toaster or an electric heater. A thermistor is a type of resistor that varies its resistance with temperature. Resistors will heat up as they slow down the current running through the circuit. In many cases, Joule heating is wasted energy. How should they be configured to produce my needed heat. The problem I have with these resistors is that the inertia is too high. If I wanted to build a circuit that would turn on a fan in the attic when it reaches a … If I stop the current when the correct temperature is reached, the temperature keeps on climbing because some heat is still stored in the resistors heatsink, and I overshoot the target temperature by 2°C for a short amount of time. Thus, photoresistors are variable resistors whose resistance values change in regard to the amount of light hitting its surface. 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