How to specify the Hurricane™
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| Specification: |
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The roof ventilators shall be CSR Edmonds Hurricane Turbine Ventilators as indicated in the drawing.They shall be manufactured from aluminium with vertical turbine vanes and incorporate the Tandaco Bearing System.
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The bases shall be vari-pitch or ridge mounting and dampers shall/shall not be provided.
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| The Ventilators shall be supported by a 15 year warranty as provided by CSR Edmonds. Dee Why NSW Australia.
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Determining the Number of Ventilators Required.
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| The number and size of ventilators required to provide an optimal, cost effective ventilation scheme for of any project depends on the air exchange rate provided. In turn, this depends on the exhaust performance
of a ventilator installed on the project and the volume of air subject to ventilation.
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Hurricane vent exhaust rates were previously based around an historical formula for predicting the performanc of gravity discharge vents, with modification for the for
the turbine action of the entilators. The calculations assumed a 6m
stack height and 10°C temperature differential. A similar calculation
has been used by most vent manufactures around the globe.
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| The historical formula had obvious flaws - it made no allowances for differences in the exhaust efficiency
between ventilatiors caused by variations in vent design or weight. Similarly, published exhaust rates did
not cater to stack height or temperature differential. |
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AS4740 |
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| Australian standard.AS4740-Natural Ventilators - Classification and performance - prescribes for the first
time a scientific procedure to establish the performance of a ventilator. |
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| The procedure enables the determination of: |
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Coefficient of discharge - Cd, and
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Flow coefficient - Cf
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| where Pw = wind siphoning pressure = ( σ /2 ) ( CfVt ) 2 |
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σ= air density at ambient temp
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Cf = Flow Coefficent
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Vt = wind velocity
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Ps = stack pressure = σ g h  T/T
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F = effective areodynamic area = Cd x A
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| Pw = wind siphoning pressure |
T = assumed temperature differential between air intake and air exhaust
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| T = assumes outside ambient temperature |
| A = throat area of ventilator |
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| Edmonds has established an algorithm which applies to each of its Hurricane vent sizes and can be applied to any project. The algorithm is exclusive to the Edmonds Hurricane (and those assembled from Edmonds full components only) as it is based on tested Cd and Cf for Hurricane. The Cd and Cf for other vents vary widely with speherical shape vents showing considerably lower Cf.
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The Edmonds Planning Algorithm. |
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| The development of this algorithm has been costly and is regarded as exclusive intellectual property for Edmonds. Edmonds invites any prospective customer or consultant to seek assistance with their projects.
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Table of Recommended Air Changes Per Hour in Zone of Occupation
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Factories anworkshops
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5 to 10 |
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| Warehouses |
5 to 8 |
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| Gymnasiums and squash courts |
5 to 10 |
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| Assembly halls |
10 to 15 |
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| Garages |
10 to 15 |
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| Toilets |
12 to 15 |
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| Laundries |
12 to 20 |
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Air change rate must perform to the local health department's code covering the type of installation.
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Stables
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Air change rate is dependent upon the |
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| Piggeries |
number of animals confined, |
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Poultry houses
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but can range between 10 to 50. |
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| VENTILATOR SIZE |
APPROXIMATE DIMENSIONS |
WEIGHT
(kg) |
DIM "A"
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DIM "B"
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DIM"C"
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| H100 |
107 |
313
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290 |
1.8 |
| H150 |
155 |
363 |
332 |
2.4 |
| H300 |
308 |
500
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477 |
4.9 |
| H400 |
410 |
564
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561 |
6.3
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| H450 |
462 |
658
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648 |
8.1 |
| H500 |
511 |
700 |
702 |
9.2 |
| H600 |
602 |
724
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766 |
12.8 |
| H700
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705
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796 |
876
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15.8 |
| H800 |
799 |
858
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1003
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20.6
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| H900 |
897
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936
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1096 |
24.1 |
Calculate & Specify