# static shock=thermocouple?

I used to live in Boston. Near my complex, there was an apartment complex with lots of our friends. Anyways, that place had faulty heating most of the time; mainly in the corridors. They were pretty stuffy.

One thing I'd noticed was that in our complex, static shocks were common but not too strong. Touching the elevator panel never did anything; and getting a doorknob shock was common but the shock was mild. One didn't need to avoid these.

In this other building, on the other hand, the elevator panels (IIRC nearly the same) gave shocks that hurt, and so did the doorknobs. I used to use my sleeve to touch things; and I'd be very wary of them.

The two complexes were nearly identical except for shape and the fact that one of them had faulty heating.

My question is, is there a correlation between faulty heating and buildup of static? A heat difference between the corridors and the inside room could generate a thermo emf in the doorknob (as well as in the elevator panel as a cooler shaft is on the other side). But, a thermo emf won't really build up static electricity, would it?

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The voltage differences you can get from thermocouples are usually in the range of $\mu$V per Kelvin for metals. In other materials this can be a bit higher but there is no material that can create thousands of Volts for a temperature difference between the heating and other parts of the building.

For static electricity you need a few conditions coming together: An object with a relatively high capacitance, e.g. your body, a method to create large potential differences, the Triboelectric effect, and a good isolation so that the charges stay on your body. This can be a plastic floor or rubber shoe soles.

Wet air is usually a good protection against static electricity, as even on the surface of very good insulating materials (Teflon, etc.) you will measure resistances of less than 10M$\Omega$ for a path of a few cm.

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If the faulty heating system was causing the air in the building to be very dry, this would perpetuate static in the air.

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Wasn't dry as much as stuffy and hot. – Manishearth Mar 7 '12 at 4:09
@Manishearth: Michael is absolutely right, in a moist environment you will hardly get a lot of static electricity. That is also the main reason why in many buildings these effects are much higher during the winter than during the summer. Maybe there was something else different like the floor material. – Alexander Mar 7 '12 at 12:36