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HC PVE : Comparisons between Induction and Impulse systems
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Comparisons
between Ducting,
Induction and Impulse systems |
Induction
System Facts and Fiction!
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Advantage
over Impulse
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Opportunity
of a lower car park build height
|
'Fact'
Only using modern Induction system
( use of induction fans can save over 600mm of excavation over a 3 story car park ) |
Yes
|
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Induction
systems offer a large saving in cable length and cost
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'Fact'
Induction systems use approx 60% less fans therefore 60% less
cable
|
Yes
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Induction
systems use less cable trays and reduced fixing time
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'Fact'
Induction systems use less cable = less fixing time =lower cost,
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Yes
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Induction
systems use less fans / Less Maintenance cost
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'Fact'
Induction systems use less fans = faster and more cost effective
maintenance
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Yes
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Induction
systems have adverse effect on sprinkler patterns
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'False'
Under test Induction fan discharge arrangement offers far superior
and more reliable flow pattern over sprinklers.
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Yes
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Reduced
size and cost of main control panel.
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'Fact'
Induction systems use less fans meaning less contactors = smaller
panel size
|
Yes
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Better
to use larger quantity of Impulse fans than lower number of Induction
fans
|
'Totally
False' Unless you are a fan manufacturer!
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Its
been said!
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| Impulse fans can be installed as direct alternatives to induction fans |
'False' Induction fans give over 3 times the performance of Impulse Fans. Using as direct replacements would seriously 'affect the fire stratagy and put at risk the well being of fire service personnel. |
Yes
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Induction
fans largely unaffected by down stand beams
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'Fact'
Unlike impulse fans, induction fans discharge at a fixed angle
for optimum flow. Fans can be mounted within 0.5m of downstand
beam and need no room behind fan as air is pulled directly from
below.
|
Yes
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Smaller
space requirement for control gear
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'Fact'
Induction systems use smaller control panels = smaller space requirement
.
|
Yes
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Smaller
diameter Impulse fans can be used to offset lower floor to soffit
heights.
|
'False'
Using smaller impulse fans results in a dramatic rise in the
quantity of fans required to move the same air.
( 1off induction = 3off 400 dia impulse fans = 6 off 315 dia impulse fans ) |
Yes
|
|
Induction
systems offer a large reduction in consumed power
|
'Fact'
lower number of fans = lower consummed power
typical example ( 3 x induction @1.2kw = 3.6kw . 9 x impulse @1.1kw = 9.9kw ) |
Yes
|
|
Induction
systems require smaller battery back up and generator size.
|
'Fact'
Lower power requirement = lower generator KVA rating
|
Yes
|
|
Induction
fan design means correct thrust determined on site
|
'Fact'
Variable speed motors on all induction fans
|
Yes
|
|
Impulse
systems offer lower system losses with less jetstream contact
with soffit
|
False
' Under test this proved to be simply rubbish .
|
N/A
|
|
Axial
impulse fans have superior performance
|
'False'
The modern day Induction fan offers a far superior system with
far better performance .
( The above statement by Hans Speulman inventor of both impulse and 12 years later the induction system ) |
Yes
|
|
Mounting
fans above car lane gives optimum system performance
|
'Fact'
It is moving cars that produce CO therefore air movement should
occur down driving lanes not over parked vehicle.
|
Yes
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|
Induction
systems can force smoke into escape routes
|
'False'
Correct system design should ensure a comparible flow rate
for Induction or Impulse systems
|
Same
advantage
|
|
Induction
is commercially and financially a more modern and sustainable
system.
|
'Fact'
Induction systems use less raw material and consume less power
both issues lead to a more sustainable system.
|
Yes
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|
Thrust
systems eliminate the need for ducting.
|
'Fact'
Both Induction and the less effective Impulse systems eliminate
the need for ducting
|
Same
advantage
|
|
Impulse
fans are quieter than induction fans
|
Both
fan types are designed to and do operate at around 50dBA within
the car park .
|
Same
advantage
|
|
Induction
fans produce more thrust
|
'True'
Induction fans are centrifugal based and currently produce up
to 100N of thrust
( max trust of typical 400 impulse fan 40N or 315 impulse 12N ) |
Yes
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|
Induction
fans induce more air
|
'True'
Induction fans induce 18 times the amount of air passing through
the fan at 50m.
( impulse fans induce 8 times the amount of air at 12m ) |
Yes
|
|
Thrust
systems offer vastly reduced system resistance means reduced power
demands.
|
Both
systems use thrust ventilation principal therefore no ducting
resistance
|
Same
advantage
|
|
Thrust
systems offer a cleaner car park environment.
|
Both
systems offer a cleaner car park environment
|
Same
advantage
|
|
Thrust
systems offer lighter, fresher, more welcoming atmosphere within
the facility.
|
Both
systems offer car parks that have a fresher more welcoming environment
|
Same
advantage
|
|
Thrust
systems offer safer environment for users.
|
Both
systems are more open and thus safer for users
|
Same
advantage
|
|
Thrust
systems offer early fire detection means less likelihood of building
structural damage.
|
Both
systems should offer a high density of multi criteria fire detectors
( 1 off every 60m2)
|
Same
advantage
|
|
Thrust
systems offer greater safety for attending fire services.
|
Moving
large quantities of air over the fire souce creates greater visability
for the attending services.
|
Same
advantage
|
|
Thrust
systems offer more reliable and effective smoke extraction and
control
|
Thrust
systems are less prone to damage and create a controlled flow
of smoke to the extraction point.
|
Same
advantage
|
|
Thrust
systems offer lower noise levels throughout the car cark.
|
Thrust
systems are demand driven and operate at the exact demands for
a given condition
( noise levels should only be high under a fire condition ) |
Same
advantage
|
|
Induction
systems are dangerous for toupe wearers
|
'False'
in over 1000 installation worldwide HC Group have never had a
problem of this type.
|
Its
been said !!
|
|
Thrust
systems offer better space optimisation (often creating more spaces)
|
Thrust
systems do not use ducting therefore more space available within
the car park.
|
Same
advantage
|
|
Thrust
systems offer vastly reduced day-to-day running costs.
|
Thrust
systems are demand driven if system calls for 3 ac/h the fans
will only operate at the required duty.
|
Same
advantage
|
|
Thrust
systems offer potentially lower insurance premiums to the car
park owner.
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Safer
more open car parks mean less potential danger to occupants therefore
lower Insurance premiums
|
Same
advantage
|
|
Induction
fans could be dangerous to people carrying long sticks
|
'False'
as above in over 1000 installations we have never had a problem
of this type.
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Its
also been said !!!
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Induction
systems offer easier and less disruptive installation.
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'Fact'
Induction systems use les fans less cabling and can be installed
faster than impulse systems at lower cost.
|
Yes
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Thrust
systems are more flexible and reliable.
|
'Fact'
Both Induction and the older impulse system are more flexible
and reliable than ducted systems.
|
Same
advantage
|