Per-window advice
Know exactly what to do with each window, and when: close, crack open, open wide, or place a fan.
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Ventilate.
At the right time.
Ventilate uses your home layout, window directions, indoor temperature, and local weather to tell you when to open, when to close, and how to place a fan, without air conditioning.
Your home
Recommendations adapt to your building, layout, window directions, indoor temperature, and the fans you own.
Weather & transitions
See what changes next and when to act. Local forecasts and timely reminders help you catch the useful cooling window.
Warnings that change the plan
Know when a tropical night, rain, high UV, or pollen changes the recommendation before your next action.
Recommendations for your situation.
Two homes on the same street can need different advice. Ventilate combines your indoor temperature, layout, windows, sun exposure, fans, and local weather into one clear next action.
Practical advice
Learn the method behind each recommendation.
The free guides explain the rules Ventilate applies: indoor versus outdoor temperature, shading, airflow, difficult nights, air conditions, and urban heat.
Your home
When to ventilate, how layout sets the cooling ceiling, and whether outdoor air is worth letting in.
7 articles
How to ventilate your home during a heatwave
Your home is not a passive box. Opened and closed at the right hours, it can stay several degrees cooler than the street.
5 articles
How your apartment layout sets the cooling ceiling
Two flats on the same street can be several degrees apart. The difference is usually layout, not luck.
4 articles
When cooler air is not worth letting in
The free question is whether it is cooler outside. The next question is whether that cooler air is actually worth opening for.
Your comfort
Once the building is doing what it can: your body, drinks, pets, and plants.
Your city
Why nights stay hot, and which public choices actually change the temperature.
5 articles
Heatwaves in European cities, and why nights stay hot
The forecast is for the region. The air at your window is for your street, and streets hold heat.
2 articles
Why cities get hotter, and what actually cools them
Some of the heat in your flat was decided years ago, by what was built around you and what was paved over.
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