Calculated Industries 4090 - Manual (Page 63)

62 — ITI S
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/HVAC P
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Inline Duct, Double Offset (Computing Offset, Length and Angle)
This example (see diagrams below) depicts two ducts offsetting both
in the horizontal and vertical planes. Basic procedures are the same
as those followed in the previous example, except a correction to
the calculated length will be required at triangle “V”.
A) Input “Measured Triangle I” to find Triangle IV:
KEYSTROKE DISPLAY
1. Enter side a, b, and c:
o o 0.
2 5 0 9 Ç m Ç 4 A 2509.
MM
2 0 9 6 Ç m Ç 5 B 2096.
MM
1 0 6 7 Ç m Ç 6 C 1067.
MM
2. Calculate and input Theta by subtracting Degree “A” (found by the
Law of Cosines) from known angle of 180°:
1 8 0 – Ç 9 /_ A 99.82668°
= 80.17332 (Theta θ)
p /_ Ø 80.17332°
3. Recall stored “b”* and input as “r”:
® 5 = d R 2096.
MM
4. Calculate “x”:
R X 357.7207
MM
5. Calculate “y”:
r Y 2065.249
MM
*The calculated dimension of “Yp” is a slant length on the same plane as line “b” in the
elevation view. The actual length is found by forming a Right Triangle (see Triangle V).
STORED
STORED
STORED