Cooling CFM calculator — Sim your flow
Airflow to remove a heat load: Q = P / (ρ cp ΔT).
When heat outruns the size of the room
A 600 W computer can need more air than the whole living room’s ventilation target. This page sizes the air that carries those watts. Then open the room in Home and see whether that air reaches through the room.
More pages
Frequently asked questions
What is Sim your flow? A 3D, real-time, browser tool where you see how air and temperature behave in a home. You draw or open an example, place a fan or AC, and follow the air live.
Do I need to know how to draw or be technical? No. Start from a ready example home, move the fan and AC, open a door, and watch what happens. If you draw your own home it does not need to be exact — rough rooms are enough to get a feel for it.
Can I test whether an AC or fan reaches the bedroom? Yes — that is one of the main jobs in Home. Place the unit, open or close doors, and see whether air and cool air get there — or stall in the living room. Move placement until it looks more reasonable.
What do I see in the live simulation? Air in motion, still corners, and how temperature changes across rooms. Colors and particles help you read the situation. It is a live picture of the field — fast feedback, not a recording after the fact.
What does the report give me? When the simulation has settled, the report sums up the result: an Airflow Score, still zones, how air spreads, and room-by-room numbers — including whether cooling or heating is heading toward the target. You can take it out as a PDF.
Is it free? Do I need to install anything? You run it in the browser, no app. Free is enough for example homes, visualization, and moving fans/AC. Pro unlocks drawing and editing your own home, saving, optimizing placement, and creating a report on your drawing.
© 2026 John Flemström · Sim your flow