Daikin VAM Series Engineering Data page 181

EDMMT712101
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(Conditions) The ventilator used is a duct type ventilator
• Necessary airflow rate: 300 m
• Duct diameter: 15 cm
• Duct length: 5 m
1 Find the intersection (A) for duct diameter d (15 cm) and airflow rate Q (300 m
2 Find intersection (B) by dropping a vertical line from intersection (A).
3 Take the scale unit of intersection (B) (2.2 Pa/m in this case) and multiply it by duct length to get 11 Pa.
 Calculation to Circular Duct from Rectangular Duct
200
(B)
(C)
Short side
VAM-HVE/HVLT Series
3
/h
300
0
(A)
(D)
40
(A)
(B)
2.2
Friction loss coefficient (Pa/m)
3
/h) that flows through the duct.
Short side
Example) For a rectangular duct of 40 × 200, the corresponding diameter
of a circular duct is 90.
I) Find the intersection (A) for the short side of 40 and the long side of 200.
II) Next find the line (B) that passes through intersection (A), and find
intersection (D) with the diagonal line (C).
In this case, the value of (D) becomes 90 by the corresponding
diameter.
Appendix
179