Can you calculate energy required to maintain heating element?

[tsx387]

Regarding a 12v source, is there a way to calculate how much energy is required to maintain a certain temperature through an element? Meaning if you want to maintain an element temperature of 35 F how much energy will it consume using 12v? How will the ambient temperature affect this equation? How much more energy will the element require if the ambient temperature is below 0?

 

[spaceboy033]

Is this a hands on project, or strictly pen+paper?

First you would want to determine the resistance of the element. Note that the element may or may not be ohmic over the range of currents you are considering. If you have the element in front of you, hook up an ammeter and take some data points at varying voltages. If all you have is a book, start looking up some resistivities of the materials you have, and measure lengths+widths of the "wire" making up the element. Ultimately, you should be able to determine the power loss from resistance using your V=IR and P=I^2R formulas.

Next thing to consider is the heat exchange. To model this, perhaps you could start with the heat equation and make some assumptions: consider the problem to be one-dimensional. If you know how to solve a differential equation, identify your boundary conditions, and solve. Otherwise, the solutions to the 1D heat equation are well known and can be looked up. As the for the dissipative constant, k, this is also material dependant and will either need to be looked up or determined from hands on measurements.

Good luck,
Ben

 

[astrokreng]

Yes, it is possible to calculate the energy required to maintain a heating element at a certain temperature using a 12v source. This can be done by using the formula for electrical power, which is P = VI, where P is power in watts, V is voltage in volts, and I is current in amperes. In this case, the voltage is 12v and the current can be calculated by dividing the power by the resistance of the heating element, which can be found in the manufacturer's specifications.

To maintain a temperature of 35 F through the heating element, you would need to determine the amount of heat energy required to raise the temperature of the element to 35 F and maintain it at that temperature. This can be calculated using the specific heat capacity of the material the element is made of and the mass of the element. Once you have this value, you can use the formula Q = mcΔT, where Q is the heat energy in joules, m is the mass of the element in kilograms, c is the specific heat capacity in joules per kilogram Kelvin, and ΔT is the change in temperature in Kelvin (35 F is approximately 274 K).

The ambient temperature will affect the amount of energy required to maintain the heating element at 35 F. If the ambient temperature is higher than 35 F, the element will require less energy to maintain its temperature as it will be receiving some heat from the surrounding environment. On the other hand, if the ambient temperature is lower than 35 F, the element will require more energy to maintain its temperature as it will be losing heat to the surrounding environment.

If the ambient temperature is below 0, the element will require even more energy to maintain its temperature of 35 F. This is because the temperature difference between the element and the environment is greater, resulting in more heat loss from the element. In this case, the energy required can be calculated by using the formula Q = mcΔT, with ΔT being the difference between the desired temperature of 35 F and the ambient temperature in Kelvin (e.g. if the ambient temperature is -10 F, ΔT would be 274 K - 255.37 K = 18.63 K).

In summary, the energy required to maintain a heating element at a certain temperature using a 12v source can be calculated by considering the power required to run the element and the heat energy required to maintain the desired temperature. The