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In our modern society filled with non-stop air conditioning and perfectly temperature-controlled rooms, we can sometimes forget the natural state of experiencing fresh air in our homes—especially in the winter or summer, when temperatures can fluctuate to the extremes.
Although most people inherently want to be comfortable, one thing (of many) that European countries do better than Americans is focusing on fresh air instead of always turning the A/C or heater on when things get slightly uncomfortable. While many European countries practice this, Germany even has a term for it: lüften.
“What is lüften?” you ask. Essentially, lüften is a German practice of opening your home’s windows to get fresh air, no matter the season. Let’s take a closer look at this ritual and the benefits of getting natural air into your home and lungs this winter.
The word lüften (pronounced more like “luff-tin” than “loof-ten) is a German term that can be used as a noun or verb, translating to “ventilation” or “to air out.” It comes from the German word luft, which means “brightness” or “air.”
Although lüften can be used year-round, the “trend” is often used more in winter to reduce stuffiness and air out a room.
It’s pretty simple: lüften means opening windows to air out a space, which replaces stale or stuffy indoor air with fresh outdoor air.
It’s thought that lüften can improve several aspects of health, including air quality (which impacts respiratory health), mood, and sleep—let’s take a closer look.
When we breathe in oxygen, we breathe out carbon dioxide. In an enclosed space, this can lead to more carbon dioxide and less oxygen.
Opening windows allows fresh air to mix with the CO2-heavy air inside, as well as improving ventilation and air quality.
Ventilation with outdoor air can remove or lessen CO2 and reduce dust, pet dander, and volatile organic compounds (VOCs) from cleaning products and furniture.
However, if you live in a high-pollution area and the air is worse outside, opening up your windows will not be beneficial for indoor air quality.
Greater concentrations of oxygen in the body may increase serotonin levels—our main “happiness hormone.”
Although we don’t know how much oxygen will be increased by opening windows, research has shown that serotonin synthesis is higher when people breathe in more oxygen.1
People also have better cognition in areas with more oxygen and less carbon dioxide. One study found that cognitive ability scores declined by up to 50% at high carbon dioxide levels.2
As oxygen is vital for all of our organs to function properly—including our brain—ensuring that the space you spend the most time in is properly oxygenated (by reducing CO2 levels) can help with energy, mood, and focus.
Opening windows lowers the indoor temperature—at least during the colder months. Research shows that most people sleep better in cooler rooms (but not too cold!).
Fresh air in the bedroom can also improve oxygen levels and air quality, benefiting sleep quality.
One study looked at how people slept with their windows open versus closed.4 The room’s CO2 concentration was lower, and air quality was better when the windows were open. However, people reported it was more noisy, and they were less rested when the windows remained open all night.
Therefore, depending on how cold it is in your region, you may not want to keep your bedroom windows open all night long, as it may get too cold or noisy.
To lower your bedroom temperature, open the windows for a few hours before you go to sleep, but close them while you’re sleeping. You don’t want your bedroom’s temperature to drop below 58 degrees Fahrenheit—according to the Sleep Foundation, the ideal temperature is 65 to 68 degrees.3
Breathing in fresher air is known to help with respiratory health, especially if you have breathing issues from allergens, dander, or dust.
Indoor air can also be dryer if you use air conditioning often. This can lead to a dryer throat or nasal passages, impacting healthy breathing.
If you don’t air out your home, mold spores and dust mites can accumulate, contributing to respiratory issues and other health concerns. Without ventilation, your home can also become too humid, leading to mold growth or mildew.
In the winter, ensure that your home isn’t becoming too cold or drafty for comfort—especially if you or someone in your household is sick. If you are shivering, it’s definitely time to close back up!
You probably don’t want to keep your windows open all day and night, but if you can safely and comfortably do so, feel free to do so.
Even 5 minutes at a time can be beneficial. You can either open all of your windows at once or rotate them depending on where you are in the house.
Although there are no set rules, some general guidelines for timing might be twice a day for 30 minutes in the warmer months of summer, 15 minutes twice a day in spring, and just 5 minutes 2-3 times per day in the winter (depending on how cold it gets in your area).
To sleep, you may want to open the windows a few hours before going to bed and then close them during the night. Otherwise, you may get too cold, or outdoor noises may wake you up more often.
Lastly, consider your surroundings when you open windows. If you are on the ground floor, ensure that you are in a safe environment, and don’t leave your windows open when you aren’t home.
Lüften translates to “ventilation” or “to air out.” It comes from the German word luft, which means “brightness” or “air.”
You can lüften for as long as you comfortably and safely can, but even 5 minutes at a time (a few times per day) can be beneficial.
If you never air out your house, you will probably have poor air quality, including a buildup of pollutants, dust, dander, allergens, and too much CO2. Mold spores and dust mites can also accumulate, contributing to respiratory issues and other health concerns. Without ventilation, your home can become too humid, leading to mold growth or mildew. Low oxygen levels and stuffy air can also impact cognitive function, mood, energy, and sleep.
Yes! We recommend the Italian “passeggiata”—the practice of taking a walk after you eat—and the Danish “hygge”—the practice of using cozy rituals to make the winter more pleasant.
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