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Rolling-Sphere Terminal Spacing / Height Calculator

For two air terminals of equal height: finds the minimum terminal height needed so the rolling sphere can't dip down and touch the structure between them, or the maximum spacing allowed for a given terminal height.

Rolling-Sphere Radius

Sphere radius (ft)

Find Required Terminal Height

Separation between terminals (ft)

Required minimum height

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Find Maximum Separation

Terminal height (ft)

Maximum separation allowed

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Geometry: sagitta h = R − √(R² − (d/2)²); solved the other way, d = 2√(2Rh − h²). This is a screening calculation for two equal-height terminals — verify against the adopted standard, terminal listings, intermediate terminals, and overall system design.

Engineering Library

Name	Category	Material	Size / Class	Diameter (in)	Use

Key	Description	Value	Unit

Formulas use JavaScript-style math expressions. Available functions include Math.sqrt, Math.pow, Math.PI, Math.max and Math.min. Invalid formulas are rejected and the last valid formula remains active.

Configuration	Formula	Variables	Description

Name	Method	Sphere Radius (ft)	Azimuth Steps	Elevation Steps	Tolerance (ft)

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