Static electricity and cold weather

Why do I get shocked so much when it’s really, really cold?

It’s not the cold, it’s the dry.

Why do I get shocked so much when it’s really, really dry?

The break down voltage (voltage at which the air will conduct an electric charge) is lower when there’s less water in the air to interfere.

According to the pdf linked to by Wiki, “1% of water vapour increases the breakdown voltage by 10.6%.” The “standard” breakdown voltage is given as 30kV/cm. As an aside, when I used to work at an explosives testing range, we had instrumentation that measured the static electricity in the air. I forget the exact value, but if the ambient electric field was above a certain amount, we were not allowed to have explosives on the range.

http://www.iop.org/EJ/article/0022-3727/25/2/012/jd920212.pdf?request-id=18ec5314-f510-4aad-8bc2-e13ab512f383

…and I think that means we act more like capacitors?

That’s a farad analogy.

Yep. The human body can store a small amount of charge on its surface. If you touch something that is a good electrical conductor (door knob, file cabinet, etc) the charge dissipates very quickly, and you get zapped. Touching something that is much more resistive to electricity will allow the charge to bleed off more slowly, and you won’t feel the zap so much.

The clothes you wear make a difference, too. Clothes like wool, polyester, and furs are really good at generating and storing charge. Clothes like cotton don’t hold a charge so well, so if you want to avoid getting zapped as much, wear more cotton clothes. You won’t be as warm, but you won’t get zapped as much either.

No need for that. Just grab something conductive you have on you like keys, tools, jewelry or coins and use that to touch a grounded object. You’ll still get a spark between the object you’re holding and the ground, but you won’t really feel it because the current passing from you isn’t confined to a small area, as it is when the spark jumps directly from you.

Booooo!

Chefguy, appears to be ample resistance to the analogy.

I don’t think this has been properly answered. My understanding (please jump in and correct me if I’m totally wrong here) is that anytime you’re moving around and coming into contact with various things in the environment, charge will be exchanged according to the triboelectric series. Dry air is a better insulator than humid air so when it is dry the charge will build up until you touch something conductive (and grounded to some extent) initiating a discharge. When the air is humid, the charge bleeds off continuously to the air and never has a chance to build up.

We’ll cross that bridge when we get to it.

I think that’s pretty much exactly what post #4 said.

And, just to bring the answer full circle to the OP’s question…

Cold air can hold far less water vapor than warm air can. Heating up the air (such as in your house, with the furnace) increases how much water the air can hold, but doesn’t add any water…and even if you’re running a humidifier in your house, odds are that the relative humidity is far lower in the winter than it is in the summer.

It was pretty much the opposite of what post #4 said, and it was also incomplete.

Because this is wrong:

which also makes this not follow:

I’m pretty sure there’s no such thing as the charge “bleeding off continuously”, the “rubbing” forces you cite simply don’t make a potential strong enough to cause an arc.

See the graph in my linked pdf for cite.

Dry air is a better conductor, therefore you need less charge for the air to break down and allow a spark.

I stand corrected.

Thanks, Santo Rugger, I did ask for someone to correct me. Your link was not accessible to me without registration (and payment?). I am surprised that I can’t find much information online that specifically address the electrical conductivity of air as a function of humidity.

Can you view other pdfs? Perhaps you can access it from the Wiki page on static electricity (it’s the third cite), instead of with my link directly. It could be that my work has a subscription to the site, I’m not sure.

No problem opening or reading pdfs normally, but I get the same registration requirement when going through the Wikipedia link.