Where Should You Put a Fan to Cool a Room?

The best fan placement to cool a room puts the fan so it pulls in cool air and pushes hot air out: face a fan out of one window, draw air in through another, and keep a clear path across the room for cross-ventilation. The CFD simulation above models airflow on your actual room layout, then recommends the optimal fan position, the number and diameter of fans you need, and which windows or doors to open — with a before/after ASHRAE SET comfort comparison.

Explore more free tools: pick your city in the fan calculator hub, check the wet bulb calculator, or read the full guides: where to put a fan to cool a room, can a fan replace AC, and why is upstairs hotter than downstairs.

Frequently Asked Questions

How do you cool a room without AC? Use fans to create cross-ventilation — one fan blowing in on the cool side, one blowing out on the hot side — open windows at night when outside air is cooler, close blinds during the day, and reduce indoor heat sources.

When should you open windows for cooling? Open them when the outside temperature drops below your indoor temperature — usually late evening through early morning — and close them once the outdoor air warms up again.