4 min read
Why dust comes back two days after you wiped, in winter
In winter, dust comes back quickly because furnace air is dry and dry air makes static, which makes dust cling to blinds, screens and electronics. Wipe with a barely damp microfiber cloth rather than a dry duster, so the dust is held instead of moved. A humidifier helps, but the EPA says to empty, dry and refill a portable one daily, clean it every third day, and keep indoor humidity under fifty percent so condensation and mold do not take its place.
Every January somebody tells me the same thing: they dusted on Saturday and by Monday the television was grey again. Nothing changed in the home. What changed is the air.
Dry air is the cause, not dirt
A furnace running most of the day in a Valparaiso winter pulls the moisture out of the indoor air. Dry air builds static, and static makes dust stick to anything with a charge: blinds, window screens, the front of the television, the plastic housing of a lamp. A dry duster or a feather duster lifts that dust into the air, where it floats for a while and settles back on the same surfaces. That is the two-day cycle.
The cloth that works
A microfiber cloth wrung out until it is barely damp. The dampness kills the static and the fibres hold the dust instead of pushing it around. Blinds, screens and electronics first, then flat surfaces, then the floor last. Do it in that order or the floor gets done twice.
If you run a humidifier
A humidifier does solve the static. It also needs looking after, or it swaps one problem for another. The EPA's guidance on home humidifiers is specific:
- Empty the tank, wipe every surface dry and refill a portable humidifier every day, so nothing grows in standing water
- Clean it every third day to keep scale and microorganisms down, and rinse well after any cleaning product
- Do not humidify past an indoor relative humidity of fifty percent
That last number is the one to watch. Above fifty percent the windows start to sweat in a cold snap, the sills stay wet, and the mold that follows is a worse problem than the dust was. A humidity gauge costs very little and sits on a shelf. Thirty to fifty is the range to aim for.
What I do on a winter visit
Damp cloth on everything that holds a charge, the humidifier tank cleaned if there is one, the return vent cover wiped on the inside, and the gauge checked. In a Northwest Indiana winter that is most of the difference between a home that looks dusty on Monday and one that does not.
Sources
- Use and Care of Home Humidifiers, US Environmental Protection Agency
