This question is a follow-up to a previous question of mine (The Relationship of Power and Heat to Length of a Resistor).
We make heaters in our lab. They are 1.5 inches long and are made using 0.005-inch-diameter (36 AWG) nichrome wire that is folded back-and-forth onto itself five times so that if you were to look at a cross-sectional area of the heater, you would see six wires.
We want to start making some heaters that are twice as long (3 inches) but still have the same heat output per cross-sectional area of heater. In other words, we want to keep the power of these heaters constant for a given point along the heater; since the heaters are twice as long, they should put out a total of twice the heat, but at a given point along the heater, they will be outputting the same heat. The heat output per cross-sectional area of heater should be the same for both heaters.
We currently use a 12-volt battery to power the 1.5-inch heaters (they are in parallel). The resistance of these 1.5-inch heaters is about 23 ohms, and thus the current through each one is about 0.52 amps. These heaters are powered for 3 seconds every 15 minutes so that they provide heat pulses for our sensors.
If I make the 3-inch heaters the same way (i.e., if I fold the same exact nichrome wire 5 times so that a cross section of the heater has 6 wires, but, for these 3-inch heaters, each fold is twice as long), I believe I would have to double the voltage to get the same heat output per cross-sectional area of heater because of the reasons mentioned in my previous post (The Relationship of Power and Heat to Length of a Resistor). The fact that the nichrome wire is folded is throwing me off, though - am I correct in my thinking, or is there something else I'm missing? If I'm missing something, what am I missing, and what is the reasoning behind it? Thank you!