When is the best time to open my windows?

Best ventilation happens when the outdoor temperature is at least 2°C cooler than indoor and humidity is below 70%. In summer that's typically early morning (5–8 AM) or after sunset. In winter, short bursts (5–10 min) of cross-ventilation a few times per day.

Should I open the windows when it's hot outside?

No. If the outdoor temperature is higher than indoor, opening windows brings warmer air in and worsens comfort. Keep them closed and shaded during the hottest hours, then open at night when temperatures drop.

What humidity level is too high for ventilation?

Above 80% relative humidity outside (especially when warm), opening windows makes indoor air feel sticky and can promote mould. Wait for drier hours or use a dehumidifier.

Is it safe to leave windows open at night?

In most weather, yes. Cool night air can drop indoor temperature by 2–5°C in 30 minutes. Check the live recommendation above before going to bed; OpenWindow.live combines temperature, humidity and air quality.

How does OpenWindow.live decide?

We compare your outdoor real-time data (OpenWeather + AQICN) against your indoor reference temperature (configurable). Hard NOs: AQI very poor, outdoor warmer than indoor, humidity > 80% in warm weather. GREEN: outdoor cooler by 2°C+ with clean air. Otherwise yellow with a partial-ventilation tip.

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Devo aprire le finestre a Hong Kong adesso?

Decisione live per Hong Kong. Aggiornata ogni 30 minuti.

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Quando conviene aprire le finestre a Hong Kong?

A Hong Kong, i momenti migliori per ventilare sono di solito al mattino presto (5–8) e dopo il tramonto, quando la temperatura esterna scende sotto quella interna.

È sicuro tenere le finestre aperte di notte a Hong Kong?

Sì, nella maggior parte dei casi. Aprire le finestre può abbassare la temperatura interna di 2–5°C in 30 minuti se l'aria esterna è più fresca.

Quanta umidità esterna è troppa per ventilare?

Sopra l'80% di umidità, aprire le finestre rende l'aria appiccicosa. Meglio aspettare ore più asciutte.

Devo aprire le finestre a Hong Kong adesso?

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