Rooftop equipment
Anchoring a box on a roof rests on a wind load. There is a standard coefficient for it, but when the shape is not standard, seeing the real distribution helps.
The decision
Which face is the wind loading, how is it distributed, and is this box shadowing the unit behind it.
Setting it up
- Model the box together with the roof plane under it; the flow sits wrong without the ground
- Set the regional wind speed
- Try several wind directions: the worst one is often not head on
What you see
- Surface pressure: which faces are pushed and which are sucked
- The wake behind the box, and whether neighbouring equipment sits in it
- Live force reads
The awkward part
This is not a structural approval calculation. Anchoring is done with the load coefficients in the governing standard; what you get here is an understanding of how the shape behaves.
The limit
This is a design-stage tool. Use it to compare shapes against each other and to catch obvious mistakes. For a number that goes to certification, approval or a signature, take the chosen shape to a validated solver or a wind tunnel.
Other analyses
Try it with your own file
Free during the beta. Request a key by e-mail and install it on a Mac running macOS 14 or later on Apple Silicon.
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