Example: find
the dimensions of a T.L. to handle 3.15m3/sec.
If required for "intake" assume limiting velocity is 2.25m/sec.
| Free area Required = |
3.15
2.25 |
= 1.4m2 |
|
From the Table
the choices are :-
| L + W |
Ht |
| (a) 2000 |
675 |
| (b) 2600 |
525 |
| (c) 3100 |
450 |
| (d) 3800 |
375 |
| (e) 4900 |
300 |
|
c. d. & e.
would probably be rejected because of their low profile.
Choice (a) would be in the T.L.A range and consequently less expensive.
In many cases the T.L. dimensions are dictated by the size of the roof
opening available. |
