# What happens when you connect hot and cold sides of Peltier device together?

I would like to know how the Peltier device would act if you heat sink the hot side WITH the cold side. Would it just sit there and consume power?

I need something to consume ~15 watts or more at 14V. Was thinking of other possibilities than a power resistor.

• "Was thinking of other possibilities than a power resistor." Is this just an exercise, or is there a reason you want to avoid using a power resistor? – Adam Davis Feb 28 '14 at 16:30
• I was wanting to see if I could find a solution to dissipate 4 times 15 watts without a sizeable heat sink. So I thought maybe flexible heat sink film connected to both sides of a Peltier device may work? – brett s Feb 28 '14 at 17:01
• Or, use 4 peltier devices with cold side of one connected to hot side of the next, and so forth until the last one only needed 1 heat sink. But I have no experience with these so it was just thoughts. – brett s Feb 28 '14 at 17:02
• The energy has to go somewhere. Whether you use a power resistor or a peltier device as you suggest, you're going to be generating heat. In fact the Pletier device will, overall, create more heat than the power resistor, so if the point is to get rid of the excess heat output while still consuming the same amount of power, you'll need to try another route. Here's a similar question which might give you some ideas: electronics.stackexchange.com/questions/85520/… – Adam Davis Feb 28 '14 at 18:13

• Just use a power resistor. It'll be cheaper and more robust. $R = \frac{V^2}{P}$, so to dissipate 15W at 14V, you'll need a resistance of about 13 ohms. – Dave Tweed Feb 28 '14 at 15:55