When I first saw a bowl of salt water on a frozen windowsill, I thought someone had left part of last night’s pasta there. The street outside was lit up by that bright white winter light that sneaks through thin glass and leaves a cold stripe on the floor. The radiators were hissing and fighting bravely, but there was still a stubborn chill next to the window.
The owner then said quietly, “That’s my aluminum foil for the winter.”
The phrase stuck.
We all know the summer trick: put shiny foil behind the radiator, reflective blinds on the glass, and do everything you can to keep the heat out. But we don’t talk about the winter version very often: the small, strange things we do to keep our warmth from leaking into the cold night.
I stopped using a compost bin after learning this method—and the garden has never looked better
A bowl, some water, and a few grains of salt.
And the room begins to feel… strange.
Why windows in the winter take away your heat (and comfort)
You can feel it right away if you stand by your window on a cold morning. That cold air that you can’t see sliding down the glass and pooling at your feet like an icy fog. The thermostat says 20°C, but your body says otherwise. The rest of the room is fine.
Windows, especially older ones, act like radiators that are turned the wrong way and don’t make any noise. They let in cold air, take in warm air, and make a draft all the time, even when they’re tightly closed.
You don’t always hear the wind.
You can feel it in your shoulders.
Rent a small apartment on the fourth floor of a building from the 1970s. Single-glazed windows, no money to fix them up, and an energy bill that goes up every November. The tenant puts folded towels on the sill, tapes the frame, and lines up a few plants to make a “green barrier.” Still, every night, the same thing happens: they put on a sweater to watch TV because the couch is too close to the window.
One day, a neighbor tells her about a bowl of salt water. She laughs and then tries it “just to see.” The glass fogs less, the sill feels less cold, and the draft by her ankles gets softer two days later. The heat hasn’t changed. Her sense of comfort has.
What’s happening is a mix of physics, humidity, and how we see things. Windows are natural cold spots because they let in warm, humid air that hits a cold surface and cools the space around it. That condensation doesn’t just fog up the glass; it also feeds mold, damages frames, and makes you feel even colder.
Salt water has two purposes. It takes in some of the moisture in the air and makes the area around the window a little more stable. Less water on the glass means fewer thermal shocks and a lower “cold wall” effect.
You don’t get three degrees more on the thermostat.
You get a small but real piece of comfort right where you need it most.
The bowl of salt water is your quiet winter shield.
The method is almost too easy, which is a little disappointing. Get a medium-sized bowl or deep dish that won’t tip over if the curtain brushes against it. You should fill it with warm water, not boiling, and add a lot of coarse salt. Stir until most of the salt is gone, even if some stays at the bottom.
Put the bowl right on the windowsill or on a small tray in front of the window. Ideally, it should be close to the coldest spot, where condensation forms.
After that, you just leave it there.
No apps, no buttons, and no big cost. Just a quiet presence by the window.
A lot of people mess up here because they think something magical will happen. One bowl, one night, and the living room is suddenly warm. It doesn’t work that way. The bowl of salt water is more like background maintenance than a big show. It slowly controls moisture, helps keep condensation from forming, and makes the “cold radiation” you feel when you sit nearby less harsh.
We’ve all been there: you try a home hack, don’t feel anything after a day, and then say, “Doesn’t work.” The bowl needs time and a beat. You should change the water and salt every few days, especially if you see a crust forming on top or the level going down.
Let’s be honest: no one really does this every day. But even doing it once or twice a week makes a big difference in the rooms that get the most light.
That little bowl by the window is strangely comforting.
It says, “I can’t fix your whole insulation problem, but I can make this corner of the room a little nicer.”
Use rough salt
Fine table salt works, but coarse grains dissolve more slowly and keep soaking up moisture for a longer time.
Pick a container that is wide and shallow.
More surface area means better air contact and more effective moisture capture.
Add it to your daily routine.
In the morning, open the window a little bit for five minutes, wipe off any condensation you can see, and keep heavy furniture away from cold walls.
Move Beyond Wavy Styles, “Brontë waves” will elevate hair this season and are simple to create
The quiet art of thermal hacks: from salt water to aluminum foil
These little seasonal gestures have a strange kind of poetry. In the summer, we put aluminum foil behind radiators or on the outside of blinds to keep the sun from coming in and making rooms unlivable. In the winter, we use quieter rituals, like putting blankets under doors, draft excluders, and now this simple bowl of salt water to protect the glass.
The logic behind all of these tricks is the same. They don’t take the place of new windows, proper insulation, or major renovations. They make the comfort you already have last longer. They help your heater work better instead of harder, and sometimes they make that one chair by the window go from “not usable in January” to “actually quite nice with a cup of tea.”
Main pointDetail: What the reader gets out of it
Lessens condensationSalt water takes in some of the moisture that would normally settle on cold glass.Less fogging, less chance of mold, and a room that feels drier and warmer
Makes the cold feel less harshKeeps the microclimate near windows stable and limits the “cold wall” effect. You can be more comfortable near windows without turning up the heat.
Simple hack that doesn’t cost muchJust a bowl, some water, and some salt that you change oftenEasy to test, available to renters and people on a tight budget
| Key point | Detail | Value for the reader |
|---|---|---|
| Reduces condensation | Salt water absorbs part of the moisture that would otherwise settle on cold glass | Less fogging, less mold risk, and a room that feels drier and less chilly |
| Softens cold sensation | Stabilizes the microclimate near windows and limits the “cold wall” effect | More comfort near windows without turning up the thermostat |
| Easy, low-cost hack | Just a bowl, water, and salt, refreshed regularly | Quick to test, accessible for renters and small budgets |
Questions and Answers:
Question 1: Does a bowl of salt water really make the room warmer?
Answer 1
A radiator heats the air, but the bowl does not. It makes things more comfortable by lowering the humidity and the cold feeling near the glass. Your body often feels the difference, even if the thermostat doesn’t show it.
Question 2: Where should I put the bowl to get the best results?
Answer 2
Put it on the windowsill or right in front of the coldest window, where condensation usually forms. You can use two smaller bowls instead of one that is hidden in a corner for big rooms.
Question 3: How often should I change the saltwater?
3. Answer
Every three to five days on average. If you see a thick white crust, smell something strange, or the level has dropped a lot, empty the bowl, rinse it, and make a new mix.
Question 4: Can I use this trick in the summer too?
Answer 4
Yes, especially when it’s hot and humid. The bowl won’t cool the room, but it can make the air feel less heavy and damp, like a basic moisture absorber.
Question 5: Is this a replacement for double glazing or insulation?
Answer 5
No. It’s a nice gesture, not a permanent fix. While you wait for the big renovation or landlord decision that will change things for good, think of it as “a wool sweater for your window.”
