Cooling your apartment without air conditioning: 12 methods that really work
When summer heat builds up indoors, your apartment can quickly turn into a sauna – and not everyone wants or is allowed to install air conditioning. The good news: You can cool your apartment without air conditioning, and noticeably so. With the right measures, you can keep several degrees of heat out – without expensive technology and without high electricity consumption.
In this guide, we show you 12 proven methods: from proper ventilation and clever use of fans to long-term measures like shading and heat recovery. You’ll also learn which supposed cooling tricks can even backfire in high humidity.
Why Your Apartment Heats Up So Much in Summer
Before you cool, it’s worth looking at the causes. Heat primarily enters your apartment in three ways: through direct sunlight on windows, through heated roof and exterior surfaces, and through internal heat sources like electrical appliances, lighting, cooking, and the residents themselves. Once the heat is in the room, it often stays there well into the night.
The most important rule of thumb follows from this: Preventing heat from entering in the first place is more effective than trying to get it out later. A large portion of the following tips focuses precisely on this – blocking out the heat.
1–3: Keeping Heat Out with Shading and Proper Ventilation
The most effective and cheapest measure is consistent shading. Keep roller shutters, blinds, or curtains closed during the day, especially on the east, south, and west sides. External sun protection like roller shutters or awnings works significantly better than internal ones because it blocks the sun before it penetrates the windowpane. If that’s not enough, reflective sun protection blinds or light, thick curtains can help.
Equally crucial is the right time to ventilate. Only open windows when it's cooler outside than inside – meaning at night and in the early morning hours. As soon as the outside temperature exceeds the inside temperature (often around 25 °C), windows should remain closed. At night, cross-ventilation with opposing windows creates a strong draft that quickly dissipates stored heat.
4–5: Using Fans Cleverly
A fan is often the first choice when it's hot – and it uses only a fraction of the electricity of an air conditioner. Important to know: A fan does not lower the measured air temperature, but rather the felt temperature. The moving air accelerates the evaporation of sweat from the skin, creating a cooler sensation. Position the device so that it creates a gentle airflow over your body or desk.
The effect can be amplified with a simple trick: Hang a damp towel in front of the fan or place a bowl of ice cubes in front of it. The evaporating moisture noticeably cools the airflow. Make sure to direct air outdoors at night and draw in cool air. You can find suitable devices and spare parts in our range for climate accessories.
6–7: Evaporative Coolers and Water – When They Help
Air coolers (also called evaporative coolers or air coolers) pass room air over a moist mat and blow it out cooled. However, this only works well in dry air, as humidity in the room inevitably increases. In German summers, relative humidity often ranges between 60 and 75 percent – and it's precisely in this range that evaporative cooling hardly works. If the air is already humid, an air cooler is more likely to create oppressive mugginess than cooling.
As a rule of thumb: At a relative humidity above 60 percent, a classic fan often provides more relief than an evaporative cooler. Caution is also advised because consistently high humidity promotes mold growth – how this is related is explained in our guide on mold due to improper ventilation. Bowls of water or ice placed in the room work on the same principle and therefore provide only limited, short-term cooling.
8–10: Reduce Internal Heat Sources and Textiles
Every switched-on device emits heat. Consistently switch off TVs, PCs, chargers, and standby consumers when you're not using them. On hot days, avoid using the oven and stove, or move cooking to cooler evening hours. Replacing old halogen or incandescent bulbs with LEDs also reduces the heat generated by lighting.
The furnishings also play a role. Roll up heavy carpets in mid-summer and swap thick curtains and bedding for light cotton fabrics. Smooth, airy materials store less heat and feel cooler – a noticeable difference, especially at night, for a restful sleep.
11–12: Plants, Shade, and Body Cooling
Green cools: houseplants release moisture through their leaves and improve the indoor climate, while facade greenery with ivy or Virginia creeper and large deciduous trees shade exterior walls and slow down the heating of the building. Where possible, awnings or sun sails are an effective addition.
Last but not least, it helps to cool your own body instead of just the room: a lukewarm (not ice-cold) shower, cooled wrists and feet, and sufficient hydration noticeably relieve the circulatory system. These small measures cost nothing and work immediately.
Staying Cool Long-Term: Insulation and Ventilation Technology
The most sustainable solution lies in building technology. Good insulation of the roof and facade, as well as permanently installed external sun protection, keep the heat out permanently. Those who are already modernizing should consider controlled residential ventilation: Many systems have a summer bypass that bypasses heat recovery and actively brings in cool outside air at night.
This not only keeps it cooler, but also ensures good air quality. You can read more about this in our article on healthy indoor climate. You can find suitable technology, from simple ventilation to complete systems, in the categories Ventilation and Ventilation Systems.
Frequently Asked Questions
How do I cool my apartment down fastest?
The fastest way is a combination of cross-ventilation at night, consistent shading during the day, and a running fan. Ventilate during the coolest period, approximately between 10 p.m. and 7 a.m., then keep windows and roller shutters closed.
Does a fan really help against the heat?
Yes – however, it lowers the felt, not the measured, temperature. Air movement cools the skin through evaporation. A damp cloth or ice in front of the fan enhances the effect, and electricity consumption remains very low.
Is an air cooler better than a fan?
Only in dry air. Since air coolers increase humidity, they provide little cooling at the typical 60 to 75 percent summer humidity in Germany and can make the air muggy. In humid rooms, a fan is usually the better choice.
At what temperature should I close the windows?
As soon as it is warmer outside than inside. In practice, this often means closing windows on hot days when the temperature reaches about 25 °C and not ventilating again until night.
Conclusion
An apartment can be noticeably cooled even without air conditioning. The key is to prevent heat from entering in the first place through shading and proper ventilation, reduce internal heat sources, and use fans cleverly. Evaporative coolers only help in dry air, while insulation and modern ventilation technology ensure a comfortable indoor climate in the long term. Combining these methods will make even the hottest days much more bearable. You can find suitable fans, air purifiers, and climate accessories for a cool home directly in our shop.
