Technical Document on Smoke Extract & Car Park Fans

The major cause of death in the event of a fire is due to smoke inhalation. Elta Fans’ smoke extract fans are widely used to assist the evacuation of occupants by creating a smoke free layer. The removal of smoke and hot gases assists in saving lives, providing fire fighting access and limiting fire and smoke damage. Smoke and heat exhaust systems are classified as safety equipment and it is essential that the smoke extract fans operate reliably in the event of a fire emergency.

The main aims of smoke and heat exhaust systems are:

• Tokeepaccessandescaperoutesclearofsmoke. • Toaidfirefightingoperations • Todelayorpreventflashoverorfullfiredevelopment • Toreducethesubsequentdamagetothebuildingstructureanditscontents.

LegislationIt is a mandatory requirement in the European Union that all smoke extract fans are independently tested to EN 12101-3:2002 Smoke and heat control systems – Specification for powered smoke and heat exhaust ventilators. This standard covers the testing, design and production controls that are required before the manufacturer can obtain product certification from the appropriate notified body. Elta Fans has extended its EC Certification for smoke related fan units with BSI, making it one of the largest certified standard product ranges available within Europe.

Compliance with the requirements of this standard shall be demonstrated by:

• Initialtypetesting • Factoryproductioncontrolbythemanufacturer.

Type Approval of a Range of Units – The Standard clearly defines the particular units from within a declared range which must be tested.

The minimum testing required can be summarised as:

• Theunitwiththehigheststressedimpeller. • Atleasttwosizesoffansattheirhighestrotationalspeed. • Theunitwiththesmallestframemotoratitsmaximumdeclaredoutput. • Themaximummotorframeatitsmaximumdeclaredoutput. • Onesizeofallthedeclaredaccessorieswithintherange.

Elta Fans’ certification was awarded following rigorous smoke test programmes.

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SMOKE EXTRACT FANS

Elta Group

46 Third Avenue, Pensnett Trading Estate, Kingswinford, West Midlands, DY6 7US, United KingdomTel: +44 (0)1384 275760 Email: [email protected] Fax: +44 (0)1384 275770 Website: www.eltagroup.com

Date: 2/11/2007 Author: Alan Macklin, Group Technical Manager

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IADInitial Type TestingThere are only a small number of approved test houses within the EU. The major ones being located at:

• BSRIAintheUK • CTICMinFrance • TUVinGermany

The essential test conditions are:

• Thefanmanufacturershouldsubmittheairandsoundperformanceoftheunitatambienttemperatureto current ISOandBSstandardsassumingstandardtipclearancesapplyandalsotakingaccountoftheincreasedclearance required for high temperature operations. • Ambienttemperaturemustbebetween15ºCand40ºC. • Volumeflowrateshouldnotchangebymorethan10%orthestaticpressurebymorethan20%duringthetest (i.e. from end of warm-up period to end of test). • After15minutesofrunningatthetesttemperaturethepowershouldbeswitchedofffor2minutes.Thefanisthen re-started and run on for its total test period.

Factory Production ControlThe purpose behind these controls is to give maximum confidence to the user, as well as the general public; that product when installed in a smoke control system is fit for purpose and will meet its stated temperature and running time.

• Fulldesignandconstructiondetailsanddrawings,aswellasmaterialsusedintheunit’sconstruction,havetobe declared at initial type testing.• Anysubsequentchangeduringtheproductslifehastobereportedtotheassessingbody,whowillattheirdiscretion require a re-test or allow the change to be applied to the original tested product.• Themanufacturershallestablish,documentandmaintainafactorycontrolsystemwhichshallensuretheconformity of the product, covering:

Control of raw and incoming materials Production process Regular inspection and procedures Routine production test procedure Thissystemshouldformpartofahighlightedprocedurewithinthecompany’sENISO9001system.

Thefanmanufacturer,whilsthavingtoholdcurrentENISO9001:2000foritscompanysystems,alsohastobeawardedits EC- Certification for the product. Elta Fans in both Fareham and Kingswinford produce the Smokevent, Jetvent and induction smoke product ranges to meet these exacting standards.

E N121 01-3 C la s s F 400 (400 ºC for 2 h ou r s)

Temp

Time

400°

Ambient

Motor off for 2

mins

Motor on for 15 mins

Test rig burner on

Figure 1. Temperature versus

Time test cycle for F400

classification

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IADImpulse VentilationVentilationofcoveredcarparksisessentialforremovingharmfulvehicleexhaustfumesandprovidingassistancetofirefighters by clearing smoke in the event of a fire. The most significant development to the car park industry in recent years has been the introduction of proven tunnel ventilation fan principles in the form of impulse fans. This innovative approach provides major benefits in terms of smoke control as well as reduced capital and installation costs. Elta’s Impulse fans eliminate the need for distribution ductwork with resultant lower extract system resistance, reduced power consumption by the fan(s), and hence savings in terms of system running costs.

The system of impulse ventilation is based on a number of small high velocity fans in place of the distribution ductwork. The impulse fans are carefully positioned to direct the airflow towards the main extract fan intake points. The main extract fansaresizedtoprovidetherequiredflowrates,butgiventhereducedneed(orcompleteelimination)ofductingwithinthe car-park area, do not have to overcome the system resistance inherent in a fully ducted ventilation system.

Impulse fans operate on well proven tunnel ventilation principles, producing a high velocity jet which thrusts against the air in front of the fan imparting momentum to all the surrounding air through entrainment as it diffuses. The volume of entrained air is significantly greater than the air quantity passing through the fan. Impulse fan performance is rated in terms of the thrust developed by the fan, which is the product of the mass flow rate times the change in velocity. In practical terms, this equates to the volume flow rate times the air density times the fan outlet velocity and is measured in Newtons (N).

British StandardsUntil recently there was no British Standard for car park ventilation, with systems being designed to the Building Regulations Approved Document F (AD-F) for general ventilation and Approved Document B (AD-B) for fire safety. The British Standard, BS7346-7: Code of practice on functional recommendations and calculation methods for smoke andheatcontrolsystemsforcoveredcarparks,waspublishedinOctober2006.Thestandardisprimarilyconcernedwith the removal of smoke and heat, but also deals with vehicle emissions due to the dual use of the ventilation systems. The standard refers to both AD-F and AD-B of the Building Regulations and includes the following four alternative approaches to ventilation:

• Naturalventilation• Ductedmechanicalventilation• Impulseventilation• Smokeandheatexhaustventilationsystem(SHEVS)

The standard gives recommendations and guidance on functional and calculation methods for impulse systems having the following three design objectives:

• Impulseventilationtoachievesmokeclearancebydispersal• Impulseventilationtoassistfirefightingaccess• Impulseventilationtoprotectmeansofescape

Figure 2. Impulse fans

running showing air

entrainment

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For further information please contact:

Elta Group Marketing Department:Jenna Chambers: +44 (0)1384 275766 - [email protected]

Tim Vaughan: +44 (0)1384 275 765 - [email protected]

46 Third Avenue, Pensnett Trading Estate, Kingswinford, West Midlands, DY6 7US, United Kingdom

Elta Fans Jetvent impulse ventilation range

Elta Fans Smokevent Fans

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The Elta Group is a £50 million family of businesses with operations in six countries on four continents which, together with a

network of international distributors, provides quality fans and related air movement equipment to customers worldwide.

Technical Document on Smoke Extract & Car Park Fans

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