Coolhouse

Heatwave? Coolhouse tells you whether to open or close your windows — right now and hour by hour — to keep your home cool, without AC.

Coolhouse — should you open the windows?

During hot weather, the right move isn't always obvious: opening at the wrong time heats your home up. Coolhouse tells you whether to open or close your windows right now — and when — to keep the inside cool, without air conditioning.

The app compares your city's outdoor temperature with your indoor temperature in real time, and applies rules drawn from scientific studies. Nothing is made up.

What Coolhouse does: • A clear verdict at a glance: OPEN, CLOSE or airing possible • The right window to ventilate, hour by hour • Tropical night warning (overnight low ≥ 20 °C / 68 °F) • Estimated indoor temperature, adjustable to how it actually feels • Next action to plan ahead (“remember to close before noon”) • Automatic location or manual city search — your last place is remembered

Science-based advice: Every rule is sourced and viewable in the app — including the WHO and building thermal-comfort standards (EN 16798-1, ASHRAE 55, CIBSE).

Your privacy: No account, no ads. Your location is used only to fetch local weather and is never shared.

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Thermal-comfort guidance, not medical advice. In an emergency, call your local emergency number.