Ventilation

Ventilation


Natural ventilation of industrial and commercial buildings, or of the above ceiling roof space in air-conditioned buildings, is a cost-effective means of exhausting hot air or achieving a sufficient degree of air change in the building.


Natural ventilation should also be considered as a means of venting smoke in a fire situation and as a means of helping to control condensation by removal of warm moist air from the building space.


The roof system can be designed to incorporate either a Dimond Fixed Ridge Ventilator or a series of Ampelair Turbo Ventilators.
Design information is given in this section to enable estimation of exhaust airflow rate and hence a reasonable basis on which to design for the air changes required.

Fixed Ridge Ventilators


The table gives approximate exhaust flow capacities for a range of stack heights (ridge height above ground), wind speeds at the ridge and internal temperature between ground level and ridge.

Achievement of these flows requires sufficient openings to provide free airflow into the building.


Dimond Fixed Ridge Ventilators are available in Zincalume®, Colorsteel®, ColorCote® and Aluminium material to match the
roofing material chosen.


Reference to Section 2.1.3.3 should be made if dissimilar materials are used.



Sizes up to and including the 300 throat can be fixed directly onto the roof without bracketing using hex head self-drilling screws, the same as the roof profile on every rib. Sizes above this require a bracketing system.

U.L.S. Wind Load
Mild Steel Bracket Size (mm)
Maximum Bracket Spacing (mm)
1.0 kPa
Mild Steel Bracket Size (mm)
40 x 5
Maximum Bracket Spacing (mm)
600
2.0 kPa
Mild Steel Bracket Size (mm)
40 x 8
Maximum Bracket Spacing (mm)
600
3.0 kPa
Mild Steel Bracket Size (mm)
40 x 8
Maximum Bracket Spacing (mm)
400

U.L.S = Ultimate Limit Slate load

Ampelair Wind Driven Ventilators


  • Locked-on rotor mechanisms prevents loss or damage in high winds.
  • Corrugated vanes provide more strength and stability.
  • Square to round base on all models.
  • Sealed dual bearing system excludes dust, grit and other foreign matter and retains lubricant.
  • Paint finish available to match roof selection.
Model
Throat Diameter (mm)
Zinaclume®
Throat Diameter (mm)
Aluminium
AS150
Throat Diameter (mm)
-
150
AS200
Throat Diameter (mm)
-
200
AS300
Throat Diameter (mm)
-
300
-
Throat Diameter (mm)
AA360
360
AS450
Throat Diameter (mm)
-
457
-
Throat Diameter (mm)
AA460
46
AS600
Throat Diameter (mm)
AA600
600

For design calculations refer to section 2.4.4.1.2 of Technical Manual

Table 2.4 Exhaust Capacity, m3/s
Stack Height Metres
Wind Speed m/s
Temp Diff °C
150 Throat ⌀ (mm)
200 Throat ⌀ (mm)
300 Throat ⌀ (mm)
360 Throat ⌀ (mm)
460 Throat ⌀ (mm)
600 Throat ⌀ (mm)
3
Wind Speed m/s
1.5
Temp Diff °C
6
150 Throat ⌀ (mm)
0.038
200 Throat ⌀ (mm)
0.068
300 Throat ⌀ (mm)
0.152
360 Throat ⌀ (mm)
0.214
460 Throat ⌀ (mm)
0.350
600 Throat ⌀ (mm)
0.609
Wind Speed m/s
Temp Diff °C
12
150 Throat ⌀ (mm)
0.039
200 Throat ⌀ (mm)
0.070
300 Throat ⌀ (mm)
0.158
360 Throat ⌀ (mm)
0.221
460 Throat ⌀ (mm)
0.362
600 Throat ⌀ (mm)
0.630
Wind Speed m/s
Temp Diff °C
18
150 Throat ⌀ (mm)
0.042
200 Throat ⌀ (mm)
0.074
300 Throat ⌀ (mm)
0.166
360 Throat ⌀ (mm)
0.233
460 Throat ⌀ (mm)
0.382
600 Throat ⌀ (mm)
0.664
Wind Speed m/s
5
Temp Diff °C
6
150 Throat ⌀ (mm)
0.084
200 Throat ⌀ (mm)
0.150
300 Throat ⌀ (mm)
0.336
360 Throat ⌀ (mm)
0.472
460 Throat ⌀ (mm)
0.772
600 Throat ⌀ (mm)
1.343
Wind Speed m/s
Temp Diff °C
12
150 Throat ⌀ (mm)
0.086
200 Throat ⌀ (mm)
0.152
300 Throat ⌀ (mm)
0.344
360 Throat ⌀ (mm)
0.483
460 Throat ⌀ (mm)
0.791
600 Throat ⌀ (mm)
1.377
Wind Speed m/s
Temp Diff °C
18
150 Throat ⌀ (mm)
0.088
200 Throat ⌀ (mm)
0.157
300 Throat ⌀ (mm)
0.352
360 Throat ⌀ (mm)
0.494
460 Throat ⌀ (mm)
0.808
600 Throat ⌀ (mm)
1.408
5
Wind Speed m/s
1.5
Temp Diff °C
6
150 Throat ⌀ (mm)
0.039
200 Throat ⌀ (mm)
0.070
300 Throat ⌀ (mm)
0.158
360 Throat ⌀ (mm)
0.221
460 Throat ⌀ (mm)
0.362
600 Throat ⌀ (mm)
0.630
Wind Speed m/s
Temp Diff °C
12
150 Throat ⌀ (mm)
0.046
200 Throat ⌀ (mm)
0.082
300 Throat ⌀ (mm)
0.183
360 Throat ⌀ (mm)
0.258
460 Throat ⌀ (mm)
0.420
600 Throat ⌀ (mm)
0.732
Wind Speed m/s
Temp Diff °C
18
150 Throat ⌀ (mm)
0.047
200 Throat ⌀ (mm)
0.084
300 Throat ⌀ (mm)
0.189
360 Throat ⌀ (mm)
0.264
460 Throat ⌀ (mm)
0.431
600 Throat ⌀ (mm)
0.751
Wind Speed m/s
5
Temp Diff °C
6
150 Throat ⌀ (mm)
0.086
200 Throat ⌀ (mm)
0.153
300 Throat ⌀ (mm)
0.344
360 Throat ⌀ (mm)
0.483
460 Throat ⌀ (mm)
0.791
600 Throat ⌀ (mm)
1.377
Wind Speed m/s
Temp Diff °C
12
150 Throat ⌀ (mm)
0.089
200 Throat ⌀ (mm)
0.158
300 Throat ⌀ (mm)
0.354
360 Throat ⌀ (mm)
0.497
460 Throat ⌀ (mm)
0.813
600 Throat ⌀ (mm)
1.414
Wind Speed m/s
Temp Diff °C
18
150 Throat ⌀ (mm)
0.092
200 Throat ⌀ (mm)
0.164
300 Throat ⌀ (mm)
0.367
360 Throat ⌀ (mm)
0.515
460 Throat ⌀ (mm)
0.844
600 Throat ⌀ (mm)
1.467
9
Wind Speed m/s
1.5
Temp Diff °C
6
150 Throat ⌀ (mm)
0.042
200 Throat ⌀ (mm)
0.074
300 Throat ⌀ (mm)
0.166
360 Throat ⌀ (mm)
0.233
460 Throat ⌀ (mm)
0.381
600 Throat ⌀ (mm)
0.664
Wind Speed m/s
Temp Diff °C
12
150 Throat ⌀ (mm)
0.047
200 Throat ⌀ (mm)
0.084
300 Throat ⌀ (mm)
0.180
360 Throat ⌀ (mm)
0.264
460 Throat ⌀ (mm)
0.431
600 Throat ⌀ (mm)
0.751
Wind Speed m/s
Temp Diff °C
18
150 Throat ⌀ (mm)
0.052
200 Throat ⌀ (mm)
0.093
300 Throat ⌀ (mm)
0.210
360 Throat ⌀ (mm)
0.295
460 Throat ⌀ (mm)
0.483
600 Throat ⌀ (mm)
0.839
Wind Speed m/s
5
Temp Diff °C
6
150 Throat ⌀ (mm)
0.088
200 Throat ⌀ (mm)
0.157
300 Throat ⌀ (mm)
0.352
360 Throat ⌀ (mm)
0.494
460 Throat ⌀ (mm)
0.808
600 Throat ⌀ (mm)
1.408
Wind Speed m/s
Temp Diff °C
12
150 Throat ⌀ (mm)
0.092
200 Throat ⌀ (mm)
0.164
300 Throat ⌀ (mm)
0.367
360 Throat ⌀ (mm)
0.515
460 Throat ⌀ (mm)
0.843
600 Throat ⌀ (mm)
1.467
Wind Speed m/s
Temp Diff °C
18
150 Throat ⌀ (mm)
0.093
200 Throat ⌀ (mm)
0.166
300 Throat ⌀ (mm)
0.371
360 Throat ⌀ (mm)
0.522
460 Throat ⌀ (mm)
0.855
600 Throat ⌀ (mm)
1.486