Static electricity in winter

Short answer: In winter, indoor air is dry because cold air holds little water and is heated without adding any moisture. Without moisture the charge stays in the fabric, which is why clothes crackle most in the cold months.

Heated air is dry air

Air at zero degrees holds very little water, and when it is warmed to twenty degrees the relative humidity drops sharply. The water stays the same, but the air can now hold much more. That is why bamboo sweatwear for men and women crackles most in January, while the same clothes behave calmly in summer.

What relative humidity means

Relative humidity tells you how much water the air contains compared with how much it can hold at the current temperature. Warm air can hold more than cold. So the same air becomes drier when heated. A small hygrometer can show the figure in your home.

Moisture on the fibres carries charge away

Above about forty per cent humidity a thin film of water forms, and the charge can run along it. Below that, it stays put. That also applies to bamboo underwear for women, where a moisture-absorbing material close to the body helps keep charge down. Fibres that bind moisture have an advantage here.

More layers mean more friction

In winter most people wear several layers. Each layer rubs against the next when you move, take off a jacket or sit down. The more different materials stacked on top of each other, the more charge can build. Choose layers in similar materials where you can.

The dryer is winter's biggest culprit

In winter the tumble dryer is tempting because laundry dries slowly indoors. But the dryer strips all moisture from the fabric and lets it rub against itself. The result is clothes that cling and crackle. Air drying takes longer, but the clothes keep a little moisture.

Practical countermeasures

Dry laundry indoors, put a bowl of water by the radiator and avoid the dryer. Air rooms briefly and fully, so the air changes without the room going cold. Then even socks for women become less static. Houseplants also release a little moisture into the air.

When it gets better

When spring arrives and heating is turned down, indoor humidity rises again. The problem then often goes away by itself. Until then, it is about giving the air and your clothes a little more moisture and avoiding the worst friction, so winter feels less static. Small habits like air drying and checking the hygrometer make a clear difference and cost very little.

Frequently asked questions

What humidity is enough

Above forty per cent almost removes the problem. An inexpensive hygrometer can show how humid the air is in your home.

Why is it worst after the dryer

Because the dryer removes all moisture from the fabric while rubbing it. That is the perfect recipe for static charge.

Does a damp towel in the dryer help

Yes, a little, but air drying works better, because the clothes keep some moisture from the air and rub less against other items.