Jet Thrust Systemthe solution to car park ventilation

1 Jet Thrust System: high performance car park ventilation

Ducted systems are the traditional approach to enclosed carpark ventilation, with fresh air levels based on a given numberof air changes per hour.

Constant running of a ventilation system, even in extendedperiods of low, or even no traffic or ventilation requirement,results in high day to day running costs.

The solution is Fläkt Woods Jet Thrust System. Ventilationcan be designed using CO and LPG sensors monitoringsystem, so that selected fans only run when necessary.Additional savings are gained because the main extract fansdo not need to be oversized to cope with the systemresistances found in ducted systems.

All our designs will be prepared to the customersrequirements, to take into account the country regulationsthat apply. If required the Jet Thrust System can bedesigned to a traditional volumetric air change rate.

Fläkt Woods realises the importance andpossible life saving function of our Jet ThrustSystem and unlike many, offers full CFDmodelling to every customer, on every project.

With over a 99% uptake by our customers, they too realise the importance of getting itright. CFD ensures system optimisation and,more importantly, that the patrons safety is not compromised.

Fläkt Woods avoids the poor design or‘guesstimates’ used by some, and employs bestpractice CFD modelling methods. This avoidsmaking a project unnecessarily expensive byusing too many fans, or an under performingsystem by specifying too few.

a different approach

Jet Thrust System is one of the most cost effective ways to ventilate, both in terms of installation cost and long term running costs

Jet Thrust Systems are designed to meet customer’s project requirements, whethera simple pollution control system, smoke clearance, or a full smoke control system

Jet Thrust System: efficient and effective 2

The Fläkt Woods Jet Thrust System is one ofthe most efficient and cost effective car parkventilation systems available on the market today. Both day-to-day pollution and emergency smokeare safely and effectively ventilated. Designed tothe highest standards and meeting the moststringent criteria to ensure all designrequirements are met.

• High System Performance

• Low Installation Costs

• Low Running Costs

• Optimises Car Park space

• CFD System Design

• Complete Turnkey Package available

Although the Fläkt Woods Jet Thrust Systemworks on surprisingly simple principles, highly trainedengineers, backed up with the latest high qualityComputational Fluid Dynamic (CFD) software, gain high system performance through skilled design.

This system design, paired with Fläkt Woods high-techproduct design, ensures an optimised highperformance system.

Fläkt Woods offers a complete turnkey solution ifrequired. Expert project management allows us todesign supply, install, test and commission, ensuringwe deliver the complete solution.

the complete solution to car park ventilation

Jet Thrust System provides effective and regular day-to-day ventilation, and high performance emergency smoke ventilation in a fire situation

3 Jet Thrust System: removing harmful contaminates

Jet Thrust System, an efficient and reliable ventilationsystem, providing clean air and removing harmfulemissions to ensure the safety of car park patrons.

Ventilation can be designed on a traditional volumetricair change rate, or by using CO and LPG sensorsmonitoring system. All our designs will be prepared tothe customers requirements, to take into account thecountry regulations that apply.

Jet Thrust System is a duct-free system, relying on aseries of strategically placed jet fans, to control anddistribute air around the car park.

Main extract fans, take the contaminated air out ofthe car park, with fresh make up air supplied from

entrance/exit ramps, or through supply fans if required.

Choice in fan sizes and profiles, operating systems anddetection systems allows versatility in the Jet ThrustSystem design, allowing the most efficient design tomeet the car park’s requirements.

Extract rates can be varied by constant CO monitoring.Sensors placed at optimum points around the car park,allowing the control system to regulate which fansoperate to dilute and/or extract the contaminated air.

The system’s high flexibility allows the most favourableoperation both in terms of safety, economy and efficiency.

pollution control

Jet Thrust System: allowing full smoke control 4

On detecting a fire emergency signal, the Jet ThrustSystem is automatically switched from day-to-day intofire mode. Jet Thrust Fan units and main extract fansare run to full design speed - reaching full speed andmaximum thrust in just a matter of seconds.

Smoke is extracted by the main extract fans, whilstsmoke control is maintained by the Jet Thrust Fans(see Diagram 1).

smoke control

In case of a fire emergency, the system’sprimary task is to limit smoke propagation insidethe car park and direct to the closest extractpoints, where the contaminated air is thenremoved from the building.

Where required, the Jet Thrust System canbe designed as a fully reversible system, usingTruly Symmetrical technology (see page 9),allowing the smoke to be evacuated to thenearest extract point. (see Diagram 2)

Full smoke control is designed to keep escaperoutes clear and allow fire fighting crews easieraccess to the seat of the fire.

Note: Not all car parks will allow or require a full smoke control system, but Jet ThrustSystem can still provide a highly effective smoke clearance or fume extract only system if required.

Diagram 1

Diagram 2

Jet Thrust System provides high performance emergency smoke control ventilation

Jet Thrust System designed to meet each customer project using state-of-the-art CFD analysis and best practice techniques

5 Jet Thrust System: : accuracy through CFD

about computational fluid dynamics (CFD)

Airflow behaviour is difficult andcomplicated to predict. Accuratecalculation is paramount in order to create an effective car park ventilationsystem. Fläkt Woods modelling is backed up with both lab test research and smoke tests in real car parks toinsure accuracy.

Manual calculation methods, used bymany, are extremely limited in their ability.Manual calculation is usually inaccurateand imprecise, which is why Fläkt Woodsoffers full CFD analysis to customers on all projects.

How it Works:

The CFD program comprises of a solver, which integrates the relevantdifferential conservation equations (Mass, Linear Momentum and Energy).The software program solves thesealgebraic equations for a finite number of iterations until an acceptable level ofaccuracy has been obtained, allowingaccurate car park design.

Fläkt Woods CFD Engineers are highlytrained and experienced, using theirknowledge and expertise to design numberand positioning of Jet Thrust Fans.

Design is verified by using industryrecognised, highly accurate, CFD modelling software, and adjusted andrecalculated if required.

Jet Thrust System: designed by engineers 6

the CFD process

CFD software allows the creation of visualisation planes, which intersect points ofinterest in the model, where contours and vectors of any stored variable, such as air speed, pressure, velocity etc., can be displayed.

Particle sources can be attached to surfaces within the model or positioned within freespace if desired. Particles are then released allowing a visualisation of general airflowmovement through the car park.

A range of parameters is considered in the analysis, including air speed and velocity, air quality and overall distribution of the airflow.

Process Stages:

1. A computer model of the layout of the car park is created. 3-D plots are sent to thecustomer for approval.

2. Once approved, the design layout of the car park and model geometry will be frozen,and detailed analysis undertaken.

3. The model is run with only the main extract fans operating. This identifies the mainbulk airflow paths from the supply to the extract points and any areas of re-circulation within the car park.

4. Jet Thrust Fans are added to the model and positioned to distribute the airflow toall of the areas of the car park, ensuring removal of any stagnant areas of air.

5. A detailed report of the results is produced for each project with appropriate airspeed plots, velocity profiles and particle animations.

CFD image showing car park geometry,

including the beams and pillars modelled

to study airflow effect. Air quality is also

shown to demonstrate air change rate.

Higher System Performance

Unlike conventional ducted systems, where there is no control over supply air, Jet Thrust Fans allowcontrol over supply air to create an even distribution of fresh air.

By controlling the air supply, a full smoke control designcan be made – something just not possible with aconventional ducted extract system.

In an emergency situation, full fan extract rate can bereached in as little as 20 seconds allowing immediateresponse to the situation. Full smoke control can bedesigned into the system, and with a fully reversibleextract system if required (see page 9).

features and benefits

Jet Thrust System offers higher performance and lower costs

7 Jet Thrust System: high performance

Lower Installation Costs

Installation costs are normally lower with a Jet ThrustSystem, compared to a ducted system.

Main extract fans are significantly smaller than forducted systems and can achieve same air-change rateperformance with smaller fans. Installation is simplersaving on labour costs, dependant on the size and formof the car park.

There are other hidden savings too. With no ductwork, other services such as, cables, gas andwater supplies, soil pipes and so on, can be routedstraight across the ceiling line, without having to divert around extract ductwork or hangers.

World Trade Centre - Bahrain

Jet Thrust System optimises space and gives improved aesthetics

Jet Thrust System: low cost 8

Lower Running Costs

Long term running costs are significantly lower, evenon a constant run system, and even more impressiveif the project uses CO/LPG sensing, to selectively runthe fans.

Far lower system resistance, compared to a ductedsystem means that less powerful extract fans are usedto maintain the same volume flow rate - meaning lowerpower operating costs and less noise pollution.

Access for routine maintenance is easy, and of course,there are no ducts and dampers to be cleaned andinspected.

Optimises Car Parking Space

Optimum use of car park space with no requirementfor low-level extract points frees up car parking space.

The low profile design fans can be used to optimiseheadroom for vehicles and pedestrians and gives amore pleasing aesthetic appearance. System Design

Unlike most other systems available on the markettoday, Fläkt Woods designs and models car parksystems using highly sophisticated and state-of-the-artCFD analysis programs.

This enables the car park to be optimally ventilated,ensuring maximum efficiency in pollution andemergency extract control.

features and benefits

Dual Tower Buildings - Bahrain

"Ice Dome" - Düsseldorf Germany

Fläkt Woods is the recognised world leader in axialfan design. Jet Thrust System is no exception.Designed using state-of-the-art Finite Element Analysis(FEA) and Computational Fluid Dynamics (CFD)computer modelling, and tested in our laboratories to optimise performance.

Both the Jet Thrust Fans and Main extractfans boast Truly Symmetrical technology.

This allows the Jet Thrust System to operatein a fully reversible mode, offering 100% thrustin both directions, and allowing the the JetThrust Fan to push or pull smoke and fumes to the nearest and safest extract point.

This reduces the time it takes to extract out of the car park, minimises the amount of smoke and maximises escape routes and fire fighting access.

Many other competitors rely on uni-directionalthrust, or where bi-direction is an option,reverse thrust is severely restricted by theirconventional blade design – this can be over40% reduction!

Fläkt Woods is the only company to offer TrulySymmetrical technology on their impellers.

truly symmetrical technology

Jet Thrust System 100% thrust in both forward and reverse operation

9 Jet Thrust System: technical excellence

Fläkt Woods was formed in 2002 with the merger of two greatWorld Leaders in their respective specialist fields: Woods AirMovement, specialists in Axial Fan technology and Fläkt; specialists in air handling, fans and climate. This brought together a combinedknowledge of air movement unrivalled in the world today.

Only high quality manufacturing processes are used. The purposebuilt, newly opened in 2006 manufacturing facility, allows consistenthigh quality product manufacture. Each impeller is individually X-rayed, ensuring all blades and hubs meet Fläkt Woods stringentlyhigh quality requirements. Only high quality marine grade aluminiumand high grade HR14 steel is used, together with highly durablefinish to ensure product reliability and longevity in service.

Jet Thrust System: design experience 10

For more help and information contact your regional sales office,

or visit our website on www.flaktwoods.com

Fläkt Woods experience applied

Fläkt Woods brand new manufacturing site opened 2006

High-tech manufacturing facility

X-rayed for quality control

Anechoic Chamber - Part of the full Research andDevelopment Laboratory facilities.

Fläkt Woods Group provides a full range of products and solutions for buildingsventilation, air treatment and industrial air movement

Sales Offices available World Wide - See our website for details

www.flaktwoods.com

Fläkt Woods Ltd Axial Way, ColchesterEssex, C04 5ZDUnited KingdomTel: +44 (0)1206 222 555Fax: +44 (0)1206 222 777Email: info.uk@flaktwoods.com

FWDD/1106/7799

Car Park Centre of Excellence

We Bring Air to Life

Due to a policy of continuous development and improvement the right is reserved to supply products which maydiffer from those illustrated and described in this publication. Certified dimensions will be supplied on requeston receipt of order.

Copyright, Fläkt Woods Ltd, 2006.

All rights reserved. No part of this publication may be produced in any material form by any means without the written permission of Fläkt Woods Ltd. Any unauthorised use of this data may result in legal proceedings.