How to specify the Hurricane™

 

Specification:

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.

The bases shall be vari-pitch or ridge mounting and dampers shall/shall not be provided.

The Ventilators shall be supported by a 15 year warranty as provided by CSR Edmonds. Dee Why NSW Australia.

Easy Calculation:

To determine the number of Hurricanes required to efficiently ventilate a building, refer to the ' EASY CALCULATION FORMULA' and select the throat size required from the Hurricane performance table.

1. Determine Volume of building in cubin metres (i.e. Length X Width X Height) = VOL
2. Select air changes per hour from table = A/C
3. Select the most suitable number of vents for the roof spaced uniformly either side of the ridge with recommened spacing of 5m. Wider industrial buildings may require one or more ventilators per bay = N
4. Determine L/sec. exhaust capacity required for ventilator for selected number of ventilators = E
   and apply equation:

E = VOL X A/C X 0.278
N

5. Select wind speed required from Ventilator Capacity Table.
6. Select the ventilator throat size which will provide the exhaust rate nearest to, but not less that, the calculated figure.
   (Note: 0.278 converts M3/hr to Litres/second.)

EXAMPLE

1. Building 45 m (L) x 20 m (W) x 5m (H) = 4500 m³ - VOL
2. Air Changes per hour required, say 5 - A/C
3. Number of Vents selected, say 8 Hurricane - N
4. Exhaust Capacity required per Ventilator - E

4500 x 5 x 0.278 = 781 L/s per vent
8

5. Average Sydney wind velocity of 12km/h selected.
6. From Performance Table select 8 off H450 Hurricane Ventilators

 

Performance Table (See Comments Below)
Throat size Of Ventilator (mm)	Exhaust Capacity Litres per Second
	Wind 6km/h	Wind 12km/h	Wind 16km/h
H100	14	33	42
H150	110	210	277
H300	270	480	620
H400	370	630	800
H450	480	790	990
H500	540	900	1240
H600	620	1104	1420
H700	944	1630	2090
H800	1233	2131	2730
H900	1560	2700	3460

 

Comments On Exhaust Rates:

Hurricane vent exhaust rates are nominally based around an original ASHRAE measure for predicting the performance of gravity discharge vents with modification for the turbine action of the ventilators. The calculations assume 6m stack height and 10 °C temperature differential. A similar calculation has been used by most vent manufacturers around the globe. The modified formula makes no allowance for differences in vent exhaust efficiency due to vent design or weight.

It is not possible under present technologies to measure the flow rate of a vent in situ. Australian Standard 4740:2000, which measures discharge and flow coefficients for rotary vents over a plenum chamber at zero stack height and nil temperature differential, indicates that vent flow rates are probably 30-40% of that provided by the modified formula. Some designs, such as Hurricane, have superior flow coefficients to spherical vane vents while any obstructions in the throat of a ventilator, such as a fan blade or motor, will decrease the discharge coefficient.

Regardless of the discrepancy between flow rates determining by the modified ASHRAE formula and AS4740:2000, the present generally accepted recommendations for air exchange rates, when applied to flow rates determined by the 'formula', produce acceptable conditions for workplaces.







 

Table of Recommended Air Changes Per Hour
Factories and workshops	5 to 10
Warehouses	5 to 8
Gymnasiums and squash courts	5 to 10
Assembly halls	10 to 15
Garages	10 to 15
Toilets	12 to 15
Laundries	12 to 20
Air change rate must perform to the local health department's code covering the type of installation.
Stables	Air change rate is dependent upon the number of animals confined, but can range between 10 to 50.
Piggeries
Poultry houses

 

VENTILATOR SIZE	APPROXIMATE DIMENSIONS			WEIGHT (kg)
	DIM "A"	DIM "B"	DIM "C"
H100	107	313	290	1.8
H150	155	363	332	2.4
H300	308	500	477	4.9
H400	410	564	561	6.3
H450	462	658	648	8.1
H500	511	700	702	9.2
H600	602	724	766	12.8
H700	705	796	876	15.8
H800	799	858	1003	20.6
H900	897	936	1096	24.1

 

Dimensions may alter from time to time.

Average Wind Velocities

During the hot months of November to March the daily recorded wind velocities in Australian capital cities exceed 6 to 10 km/hr for 96% of the hours between noon and 3pm.

NOTE: A wind speed of 6 to 10km/hr is defined as a light breeze. Wind is felt on the face, leaves rustle and vanes move by wind.

The average wind velocities for a 12 month period in km/hr are:
Sydney 12.5, Brisbane 10, Melbourne 13, Adelaide 14.4, Perth 14.4, Darwin 9.8, Hobart 11.5, Canberra 6.4. (Source : Bureau of Meteorology).