A bowl of salt water by the window in winter works as effectively as aluminum foil does in summer.

The first frost came overnight, quietly tracing lace-like patterns across the windowpanes. By 7 a.m., the glass was sweating on the inside-cold mist sliding down toward the sill and soaking the corner of a curtain. The radiator gurgled in protest, working hard, yet the room still felt damp and heavy, like the kind of winter air that settles into your bones. You wipe the window with your sleeve; it clears for a second, then instantly fogs again.

That’s when a neighbor mentions a strange trick: a simple bowl of salt water by the window.

It sounds like something out of a grandmother’s notebook.

But you try it once, just to see.

A winter problem hiding on your windowsill

On cold mornings, windows turn into tiny weather stations. Inside, the glass goes cloudy with condensation-beads of water lining up like little soldiers, then sliding down in slow motion. The frame stays wet for hours. The plaster around the window starts to darken, sometimes even forming black spots. You can feel the chill leaking in, even with the heat running.

You open the window to “air things out” and mentally watch your energy bill climb.

Picture a small bedroom: one person sleeping, door closed, thick curtains. Overnight, every breath loads the air with moisture. By sunrise, the window looks like someone misted it with a spray bottle. You wipe it with a microfiber cloth; ten minutes later, it’s back. In some homes, that cycle repeats every day from November to March. Wallpaper starts to bubble, wood swells slightly, and that unmistakable musty smell starts to settle in.

The room looks clean, but it doesn’t feel clean.

What’s happening is simple physics. Warm indoor air holds a lot of water vapor. When that air hits cold glass, the temperature drops suddenly and the air can’t hold as much moisture. The water condenses and sticks to the surface. In summer, aluminum foil on windows reflects heat away from the glass. In winter, salt water doesn’t reflect anything-but it plays another clever role: it quietly pulls some of that excess moisture out of the air before it ends up on your window.

A bowl of salt water: how this “grandmother trick” actually works

The method sounds almost too basic. Take a bowl or shallow dish, add warm tap water, then dissolve a generous handful or two of table salt, coarse salt, or even rock salt. Stir until you have a saturated solution-where a little salt still sits at the bottom. Then place the bowl on the windowsill or as close as possible to the cold pane.

From that point on, the bowl acts like a quiet moisture sponge for the room.

Don’t expect a dramatic change in five minutes. Think of it as a slow, steady helper working in the background while you go about your day. Salt water attracts water molecules from the air, especially in small, enclosed spaces: bedrooms, home offices, laundry corners, window nooks behind thick curtains. You’ll notice the glass fogs up less, droplets are smaller, and the sill stays dry longer.

Let’s be honest: hardly anyone wipes their windows every single day.

That’s why simple, passive tricks like this stick.

What many people get wrong is placement and expectations. The bowl needs to be in the “path” of humid air, close to the cold zone-not hidden behind books or decorations. And it won’t fix a serious moisture problem on its own, like a major leak or no ventilation at all. It’s a helper, not a miracle cure.

Used well, though, this tiny setup plays the same seasonal role as aluminum foil in summer: an easy barrier against an invisible enemy-just flipped for winter.

Doing it right: from quick setup to daily rhythm

Start with the right container. A low, wide bowl works better than a tall, narrow glass because it exposes more surface area to the air. Fill it halfway with warm water, then add salt until it stops dissolving easily and starts collecting at the bottom. That undissolved salt is your sign the mix is “maxed out.” Place the bowl on the windowsill or on a small tray under the window to prevent salt marks on painted surfaces.

Leave a little space around it so air can circulate freely.

After a few days, check the bowl. The water level may change, and a salt crust might form along the edges. That’s a good sign-the salt has been absorbing moisture. You can stir it, add more salt, or replace the mix entirely about once a week. Many people give up because they think “nothing is happening” after 24 hours.

We’ve all had that moment when a home tip seems pointless at first.

The key is consistency, not perfection. Small, repeated habits change a room’s atmosphere more than one big cleaning day.

Some heating technicians even admit they use DIY salt absorbers at home: “In winter, I prefer a bowl of salt water and a five-minute airing to running the radiators full blast with wet windows,” said one installer who visits dozens of damp apartments every season.

• Place one bowl per room that feels “stuffy” or shows condensation.
• Pair the salt bowl with short, brisk airing (5–10 minutes with windows wide open).
• Keep curtains slightly off the glass so air can circulate.
• Wipe visible morning condensation to stop mold before it starts.
• Use extra bowls near drying racks or radiators where laundry hangs.

Rethinking comfort: small gestures, big winter impact

A bowl of salt water by the window won’t turn an icy apartment into a ski-lodge lounge overnight. But it changes something more subtle: how the room feels. The air feels lighter, windows stay clearer, and you don’t start every day with a cloth in hand, fighting droplets on the glass. It’s a small, almost invisible object that quietly says, “This home pushes back against winter.”

And over time, that protects not only walls and window frames, but also your mood.

Behind this trick is a bigger idea: winter comfort comes from a series of micro-habits. A bowl on the sill. Five minutes of airing instead of keeping windows cracked all day. One less damp towel tossed on the bed. A curtain adjusted so the glass can “breathe.” None of it is impressive on its own. Together, it reduces mold risk, keeps energy use in check, and makes mornings a little less gloomy.

Sometimes, the smartest “device” in a home doesn’t plug into anything.

Key point	Detail	Value for the reader
Salt water absorbs moisture	A saturated salt solution attracts water vapor from the air	Less window condensation, fewer damp surfaces
Placement matters	Bowl should be wide, near cold glass, with good air circulation	Maximizes results without buying special equipment
Works best with simple habits	Combine with brief airing and wiping stubborn droplets	Better indoor comfort and lower winter mold risk

FAQ

• Does a bowl of salt water really replace a dehumidifier? Not completely. A dehumidifier is more powerful and better for very damp homes. The salt bowl is a light, low-cost aid for mild condensation-not a full solution.
  
• What type of salt works best for this trick? Any household salt: table salt, coarse salt, or rock salt. The goal is a saturated solution with some undissolved salt at the bottom.
  
• How often should I change the salt water? About once a week, or sooner if it looks crusted over or dirty. Stirring every few days helps “reactivate” the effect.
  
• Is it dangerous for pets or children? Salt water isn’t toxic by itself, but it isn’t meant to be consumed. Keep bowls out of reach of kids and pets, and use stable containers on higher sills when possible.
  
• Can I use this method in summer too? Yes-especially in humid spaces like bathrooms or laundry areas. In winter it targets window condensation; in summer it can help reduce that sticky, heavy feeling on very humid days.