ASHRAE Qatar Oryx Chapter: 09.04.2016

Introduction to Design of Car Park ventilation using JetFans & CFD analysis as QCD

Presented by Paul Mason Business Development Manager Soler & Palau

Ventilation Fundamentals

Why ventilate?

Where & When Ventilate?

Fire; Risk or Not?

Basic Principles

Ducted System

Impulse Ventilation / JetFan System

How Does It Work?

Comparison Ducted v Impulse / JetFan.

Regulations by Country

Qatar CD FSS requirements

AGENDA

Smoke Control

Road Tunnel

Car Park

Car Fire Heat Release Rate HRR

Impulse Ventilation; Fundamentals for Design

Required Information

Fundamentals for Design

Impulse Ventilation – Comissioning

Fan products

CFD Project examples

Questions

AGENDA

WHY VENTILATE?

POLLUTION, FIRE SMOKE, FIRE HAZARDS, FIRE SAFETY.

• Pollution:- Typical pollutant:- Carbon Monoxide CO A colourless, odourless toxic gas produced by incomplete combustion

of fuels such as petrol and diesel. Indoor CO guidelines:- 15 minutes: 100mg/m3 86ppm. 1 hour: 35mg/m3 30ppm. 8 hours: 10mg/m3 9ppm.

Source: World Health Organisation (WHO) Guidelines for indoor air quality, 2009.

For enclosed car parking:- UK BS 7346-7:2013 refers:- 15 min: 90ppm. 8 hour average: 30ppm. ASHRAE Handbook refers:- 8 hour: 25ppm.

Other Pollutants:- CO2, NOx, NO2, Soot etc… Consider:- Is incoming air, FRESH?

Fire smoke

• Fire smoke:-

The airborne solid and liquid particulates and gases evolved when a material undergoes pyrolysis or combustion, together with the quantity of air that is entrained or otherwise mixed into the mass.

Source:

NFPA 92 – 2012, Chapter 3.3.13

ASHRAE Chapter 53

Fire smoke

Smoke Inhalation

Fire smoke

• Smoke inhalation: Is the primary cause of death in victims of indoor

fires. It is estimated that 50–80% of fire deaths are the

result of smoke inhalation injuries, including burns to the respiratory system.

The hot smoke injures or kills by a combination of thermal damage, poisoning and pulmonary irritation and swelling, caused by carbon monoxide, cyanide and other combustion products.

Source: eMedicineHealth

Smoke…causes the most deaths in fires. Source ASHRAE Chapter 53

Flashover

Fire Hazards

• Flashover:-

Is the near-simultaneous ignition of most of the directly exposed combustible material in an enclosed area. Flashover occurs when the majority of the exposed surfaces in a space are heated to their auto-ignition temperature and emit flammable gases. Flashover normally occurs at 500°C +

Source: Backdraft and flashover; what's the difference?, V.Dunn, Deputy Chief, F. D. N. Y. (Ret.), 2011

• Backdraft:-

Is an explosive event at a fire resulting from rapid re-introduction of oxygen to combustion in an oxygen-starved environment, for example, the breaking of a window or opening of a door to an enclosed space. Backdrafts present a serious threat to firefighters, even those with a high level of experience

Source: Backdraft and flashover;

what's the difference?

V.Dunn, Deputy Chief, FDNY. 2011

Backdraft

Fire Hazards

WHERE & WHEN VENTILATE?

Design Fundamentals:- Includes one or more of the following

1. Containing the smoke to the zone of fire origin. 2. Maintaining a tenable environment within exit

stairwells for the time necessary to allow occupants to exit the building.

3. Maintaining a tenable environment within all exit access and smoke refuge area access paths for the time necessary to allow occupants to reach an exit or smoke refuge area.

4. Maintaining the smoke layer interface to a predetermined elevation in large volume spaces.

Source: NFPA 92: 2012 Chapter 4.1.2.

• Where to use: – Staircase Pressurization – Atria – Car Park

• When to use: – To assist safe evacuation of occupants – To assist fire fighter access

• Typical Design guidance: Europe: BS 7346-7, EN 12101-6, CEN/TR12101-5 USA: NFPA 88A Standard for Parking structures, NFPA 92 Standard for Smoke Control Systems. ASHRAE Handbook smoke Control

Emergency Extract

Fire safety

Pressure differential:-

• Protection of emergency escape routes

• Create positive pressure to resist smoke

entry to escape route (+50Pa)

• Use of pressure relief to atmosphere to

balance door openings

• Provide sufficient airflow through door

openings to resist smoke flow. (0.75 / 2.0 m/s)

Pressure differential systems

• Design guidance refer EN12101-6:

• NFPA 92.

Large spaces, Atrium:

• Design guidance refer TR12101-5:

• NFPA 92.

Staircase Pressurisation & Atria

Fire safety

FIRE, RISK OR NOT?

• Place Vendome, Paris, France • 2012.03.08

• Car park, 35,000m², on 5 floors

• Ducted ventilation, no sprinklers

• 1,400 car spaces

• 40+ cars burnt. Source: news web

Real Risk - FIRE

Fire risk?

Source: Pompier de Paris

• Parking del Ensanche, Spain

• 2012.12.24

• Car park, 7,400m² on 3 floors.

• Ducted ventilation, no sprinklers Source: EITB news web

Real Risk - FIRE

Fire risk?

Source: EITB

• Car Park, Brighton UK

• 2015.04.04.

• No sprinklers. Source: Brighton & Hove News web

Real Risk - FIRE

Fire risk?

Real Risk - FIRE

Fire risk?

• Parking, Tesco supermarket, Oldham, UK

• 2015.07.29

• Fireman;- “Three cars were on fire. The store evacuated everyone really quickly and thankfully there were no casualties”

• No sprinklers.

BASIC PRINCIPLES DUCTED SYSTEM

Historical use of ducts for extract ventilation.

Fresh air inlet may be uncontrolled

Historical Ducted Car Park Ventilation

Basic Principles

EXHAUST FANS

5 ACH LOW LEVEL

DUCT

Fresh air

Extract fans 6 -10 ACH

50 % air at

low level

NPV 6 ACH – Normal Pollution Ventilation at high and low level

EM 10 ACH – Emergency extract 50% high and 50% low level

50 % air at high level

Basic Principles

Ducted Method

Duct Installation

Basic Principles

Examples of ducting within car parking

area, to show conflict with other services.

More examples of ducting within car parking area,

to show conflict with other services!

Basic Principles

Duct Installation

Ducted System

• Extract Ducts:

– Take up space

– Increase fan pressure

– May conflict with other services: • Pipes

• Sprinklers

• Electrical

• Lighting

Basic Principles

BASIC PRINCIPLES IMPULSE VENTILATION SYSTEM

Jet Fan

Jet Fan System

Basic Principles

What is a Jetfan?

Jetfan system

Impulse fan

Induction fan

Thrust fan

In this presentation all these are referred to as: Jetfan

Fresh air

Jet Fan

NPV 6 ACH – Normal Pollution Ventilation

EM 10 ACH – Emergency Smoke Clearance

EM Calculated – Emergency Smoke Control

Jet Fan System

Basic Principles

Extract fans 6 - 10 ACH or Calculated for Smoke Control

Jet Fans System – Without Ducting

BASIC PRINCIPLES IMPULSE VENTILATION SYSTEM

HOW DOES IT WORK?

• Main Extract Fans provide – Required Air Changes per Hour (ACH) – Flow rate per car parking space – Required Smoke Control extract rate

• Air is drawn in via – Ramps – Louvers – Shafts – Or supplied by fans

• Jet Fans Induce the air/smoke towards extract points

Jet Fan System

Basic Principles

Jet Fan System – Smoke Clearance

Basic Principles

Air is drawn in, and Jetfans local to the fire operate to induce air and smoke toward the extract points

• No ducting in the parking area – Reduced fan pressure – Reduced power consumption (kW) – Reduced cost

• No ducting to be damaged, cleaned, maintained, or obstruct other services, piping, electrical, sprinklers…

• More space for parking • Improved visibility, CCTV, and appearance in parking

area • May reduce height of car park, saving building cost • Jetfan ventilation can provide Smoke Clearance, as ducts • Jetfan ventilation can also be sized for Smoke Control

Jet Fan VS. Ducted Ventilation

Potential Benefits

Jet Fans System – Without Ducting

Potential Benefits

COMPARISON DUCTED V IMPULSE

CFD –Technologies Comparison

Car park – Spain comparrison.

Description:

• Fire Simulation in Basement -2

• Height: 2.84m

• Floor Area: 1,910 m2

• Air inlet through interconnecting ramp

• Flat Ceiling

• Extract points quantity: Variable

• Radiation 25%

• Fire Size:

• Width 2m

• Length 5m

• Jet fans Delay: 180s (130s after fire ignition)

• CFD End Time: 500s

Location 1

Location 2

Ducted System

Description:

• Smoke Clearance – Fire location 2

• 2 Ducts

• 47,530 m3/h to Spain Regulations

• 13 extract grilles of 500 x 300mm

CFD –Technologies Comparison

Impulse Ventilation System

Description:

• Smoke Clearance – Fire Location 2

• 1 Extract Point

• Extract Airflow 53,960 m3/h (10ACH)

• 1 Extract Grille of 3000 x 1000mm

• 3 x TJHU/2/4-315-BC 0,8/0,2kW F400

• 1 x IFHT-75N 4/8-C 2,2/0,37kW F400

CFD –Technologies Comparison

Impulse Ventilation System

Descripción:

• Smoke Control – Fire Location 2

• 1 Extract Point

• Extract Airflow 155,000 m3/h

• 1 Extract Grille of 4000 x 2000mm

• 2 x TJHU/2/4-315-BC 0,8/0,2kW F400

• 4 x IFHT-75N 4/8-C 2,2/0,37kW F400

CFD –Technologies Comparison

CFD – TECHNOLOGIES COMPARISON FIRE LOCATION 2

Ducted System – Smoke clearance

Main Conclusions

• Low air velocities on the right side

• Low Visibility

• High Temperature

Velocity

Visibility

Temperatures

CFD –Technologies Comparison

CFD – Comparación Tecnologías Impulse Ventilation System

Smoke clearance

Main Conclusions:

• No significant stagnant air areas

• Homogeneous Visibility

• Lower Upstream Temperature

Velocity

Visibility

Temperatures

Impulse Ventilation System

Smoke Control

Main Conclusions:

• No stagnant areas

• Visibility more than 10m

• Temperature lower than 60° C

• Firefighter access from lower left stair

Velocity

Visibility

Temperatures

CFD –Technologies Comparison

REGULATIONS BY COUNTRY DESIGN & ACCEPTANCE CRITERIA

Ventilation requirements by country

Regulation Ventilation NPV Pollution Smoke EM Temp deg C

Europe

UK BS 7346-7:2013 6 ac/h CO 30ppm-8h 10 ach 300 / 1h

CO 90ppm-15min

ROW

Bahrain 6 ac/h 10 ach 300 / 1h

Dubai DCD 6 ac/h 10 ach 300 / 1h

DCD 6 ac/h Performance Based

Oman 6 ac/h 10 ach 300 / 1h

Qatar NFPA 88A 300L/min/m2

ASHRAE ch15 6 ac/h CO 25ppm

QCD FSS 6 ac/h 10 ach 300 / 2h Ducted systems - Smoke Clearance

QCD FSS 6 ac/h Performance based 300 / 2h Jetfan systems - Smoke Control

Jordan 6 ac/h 10 ach

Egypt 6 ac/h 8 ach 200 / 2h With sprinklers

USA ASHRAE 7.6 l/s / m2 CO 25ppm-8h

CO 35ppm-1h

USA NFPA 5 l/s / m2 300 l/min / m2 NFPA 88A 2011

QATAR CD FSS REQUIREMENTS

Qatar CD GA 7.0 : Guidelines Annex – Ventilation and Smoke Control

4.7 Car Parks

4.7.1-3 Car park ventilation systems employing thrust fans shall be confirmed through performance based analysis. The use of CFD fire modeling and the following input parameters shall be considered in the design.

4.7.1-4 Design fire size: 4 MW (2m x 5m) with automatic sprinklers

8 MW (5m x 5m without sprinklers

4.7.1-6 Design fire: Flaming polyurethane

4.7.1-7 Design fire: Most onerous location

4.7.1-8 Acceptance criteria 1.8m above floor, 10m radius of fire, 20 minutes.

a) Minimum 10m visibility upstream

b) Temperature of smoke layer not exceed 60°C

4.7.1-9 CFD simulation must be minimum 30 mins

grid size max 0.2 x 0.2 x 0.2m within 10m of fire, and max 0.4 x 0.4 x 0.4m elsewhere

4,7.1-10 Sensitivity study for loss of Jetfan.

FIRE SMOKE CONTROL

EXAMPLE ROAD TUNNEL

Smoke control - Road Tunnels

Smoke Velocity (Vs) Typical 1 – 1.5 m/s

where: Tunnel: 10m (w) x 5m (h)

Car Fire 8MW

Basic Principles

• Based on Heselden’s method of predicting smoke velocity

• Refer: ASHRAE Handbook Chapter 15.

NFPA 502,

Critical velocity of 1 - 1.5m/s

CAR FIRE – 3MW

Induced air

JETFAN

Velocity > 18m/s

Jet Fan Energy from fire

moves smoke

Vs = 2.8m/s

Smoke Velocity (Vs)

Smoke control - Road Tunnels

Basic Principles

FIRE SMOKE CONTROL

CAR PARK

Smoke Perimeter

Ps

Inlet air via ramp

Extract Fans

Fire-fighters

access

Smoke control – Car parks

Basic Principles

For Car Park the tunnel theory is adapted to take Ps to be Smoke Perimeter

Fire fighter access to within 10m in tenable conditions

Smoke control – Car parks

Basic Principles

Extract Fans

Inlet air via ramp

Fire-fighters

access

Smoke Perimeter

BASIC PRINCIPLES – SMOKE CONTROL

HOW MUCH HEAT AND SMOKE IS PRODUCED BY A CAR FIRE?

where:

M = Mass rate of smoke production (kg/sec) = 11.62

P = Perimeter of fire (m) 14m

Y = Height of smoke layer (m) 2.5m

Ce = Constant 0.19 / 0.21 / 0.34

M

Y

M = CePY3/2

P

Source: BRE 368:Large Plume Model

M

Fire smoke Calculation of the rate of fire smoke

production

(K) mpambient te Absolute x kg/m³ 1.22

(K) layer temp smoke Absolute x (kg/s) production Smoke (m³/s) smoke of Volume

where:

• Effective height of Car Park = 3 m

• Effective height of Clear Layer Y = 2.5 m

• Fire perimeter P = 14 m source GA _7.0 or BS 7346-7:2013

• Design Fire size HRR = 4MW source GA_7.0 or BS 73467:2006 (with sprinklers)

• Radiation to structure ? To obtain Convective heat flow in gas kW

• Absolute ambient temp (K) ? = 273 + 46 = 319K

Smoke Control

Calculate Smoke Volume Flow

where:

c = 1.012 [kW / (kg·K)]

Q = convective heat release rate [kW]

M = mass of smoke production [kg/s]

θ = temperature of smoke layer, above ambient [K]

(K) mpambient te Absolute x kg/m³ 1.22

(K) layer temp smoke Absolute x (kg/s) production Smoke (m³/s) smoke of Volume

where:

• Effective height of Car Park = 3 m

• Effective height of Clear Layer Y = 2.5 m

• Fire perimeter P = 14 m source GA _7.0 or BS 7346-7:2013

• Design Fire size HRR = 4MW source GA_7.0 or BS 73467:2006 (with sprinklers)

• Convective Radiation to structure

• Absolute ambient temp (K) = 273 + 46 = 319K

• Volume of smoke = 16.84 m³/s

• Absolute smoke layer = 557K (557 – 273 = 284° C)

• Refer:- H Morgan Technical paper – formulas, NFPA 92, ASHRAE Handbook

Smoke Control

Calculate Smoke Volume Flow

Actual car fire tests Source: BRE Report Fire spread in car parks BD 2552: 2010

Source: UK CLG / BRE report BD2552 Fire spread in car parks.

Fire Testing

HRR VS. time

Fire Test

Test 1 – 3 cars, no sprinklers

Heat Release Rate (HRR)

Test 1: 16MW @ 21 min from ignition

Source: UK CLG / BRE research 2006-9

Test 2 – 3 cars, sprinklers

Fire Test

Source: UK CLG / BRE research 2006-9

Heat Release Rate (HRR)

Test 2:

• <1MW @ 41 min from ignition

• 7MW @ 54 min from ignition

CAR PARK IMPULSE VENTILATION

FUNDAMENTALS FOR SMOKE CONTROL

Fundamentals for Design

• AutoCAD Drawings – Layout

– Sections

• Down-stand obstructions

• Sprinklers system

• Identify aceptable extract / supply air points.

• Zoning (virtual / physical)

• Fireman access points

Required Information

• Impulse fans location according to:

a. Geometry

b. Supply points

c. Exhaust points

Exhaust

Supply

Final Design

Pre Study (PS)

• Analysis of inputs: a. Geometry:

a. Surface

b. Height

c. Obstructions

b. Mark locations: a. Ramps

b. Supply Points

c. Exhaust Points

d. Suggest if N/E

c. Suggest / Consider: a. Zoning (Physical / Virtual)

b. Openings

c. Escape routes

d. Access for fire-fighters

Exhaust

Supply

Partial Design

Airflow

Fundamentals for Design

Desgin Criteria

Boundary Conditions

• FA and EA should not be too close

– Avoid short-circuit

– Avoid non natural

air movement

– Avoid risk of outflow, or compromising ramps

If unable to achieve acceptable cross flow ventilation, to allow fireman access, or air flow rate, then maybe not possible for Smoke Control ?

• Jet Fans Activation System

– Manual

– Timer

– Pollution Detection System

• Low Pollution

• High Pollution

– Fire Detection System

• Smoke

• Rapid Temperature Rise

• Multicriteria

• Jet fans Operation System – Delay?

Control the System

Fundamentals for Design

Calculation :-

Now consider Car Park Calculation :-

Refer Technical paper:-

Extending the principles of Impulse Ventilation in Tunnels to apply to smoke control in car parks.

H.P. Morgan http://www.bse.polyu.edu.hk/researchCentre/Fire_Engineering/summary_of_output/journal/IJEPBFC/V6/p.53-71.pdf

Also NFPA 502

Calculate air / smoke flow

Extract Fans’ Airflow

Smoke Production

Smoke reservoir

Advance Nose Velocity + JF cooling effect

Advance Nose Velocity

M = CePY3/2

Flat Ceiling

Longitudinal Beams

Transversal Beams

hg

vFr

as

a

..

.²

2

Real Test

NFPA 502

CAR PARK IMPULSE VENTILATION

COMISSIONING

Real Fire Tests: IKEA, Caen

Cold Smoke Tests: San Mames, Bilbao

http://www.youtube.com/user/SyPVentilation?feature=mhsn#p/u/5/pj-ScGU_TX8

Jet Fan Operation

TYPICAL FAN PRODUCTS FOR CAR PARK VENTILATION

Product

Qatar requirement:- QCD FSS 1.1 Basic Requirements, Item 19.0. 28.06.2010 Temperature rating of fans for Smoke Control Systems “Smoke control fans must be UL Listed, FM approved, CE mark or LPC certified” “Fans must be capable of operating at minimum 250°C for 2 hours”

Product

QCD FSS 1.1 Basic Requirements Item 19.0 Temperature rating of fans for Smoke Control Systems UL Listed, FM approved: Unable to identify an applicable test for powered ventilation fans. UL 793 refers to “automatically operated roof vents” Refer: UL web http://ulstandards.ul.com/standard/?id=793 FM has no entry for powered ventilating fan. Refer: FM web http://www.fmapprovals.com/ ASHRAE 149-2000 applicable?

Product

QCD FSS 1.1 Basic Requirements Item 19.0 Temperature rating of fans for Smoke Control Systems EN 12101-3 is specifically for “Smoke and heat control systems. Specification for powered smoke and heat exhaust ventilators” This is a series of prescribed tests by an independent Test house to approve a range of products. This is mandatory in Europe to obtain CE mark. This is mandatory to obtain LPC listing.

Product

EN 12101-3 • Applicable to powered smoke and heat control ventilators. • Typical JetFan test is completely submerged in the furnace. • Independent test of highest stressed samples from range. • After 15 mins, switch off fan for 2 min, then restart. • Typical test temperatures: F200, F250, F300, F400 • Ongoing inspection of factory production. • Certification enables use of:-

Product

Fan Types • Applicable to:- • Axial, • Centrifugal, • Roof, • JetFans,

Product

Typical EN 12101-3 Independent test approval:-

The following examples are made with:- Fire Dynamics Simulator (FDS) and Smokeview (SMV) has been developed by NIST – USA. FDS is a large-eddy simulation (LES) code for low-speed flows, with an emphasis on smoke and heat transport from fires. SMV is a visulization program used to display the output of FDS and CFAST simulations Refer validation test reports from NIST and 3rd parties Refer https://pages.nist.gov/fds-smv/index.html There are other CFD tools that may also be suitable. The user should ensure that any tool used is validated for application, especially if used for smoke analysis.

CFD is a powerful, rapidly evolving tool used for the prediction and analysis of fluid flows. The technique is able to provide a time-dependent three dimensional approximate solution to the highly coupled differential equations that govern fluid flows. However, a number of assumptions and approximations are made throughout. Source: HSL Buxton, UK – Guidance for HSE Inspectors. “poor information in = poor information out”

Key points for assessing CFD results:- The practitioner must have an in-depth understanding of mechanical ventilation, CFD, fire and smoke dynamics. The CFD code employed should be validated for application to fire and smoke movement. The level of geometric detail represented should include anything that might significantly affect the flow. The design of the computational grid – disposition of grid cells and their size should be based on an understanding of the key flow phenomena and experience. Boundary conditions, Smoke transport….. Source: HSL Buxton, UK – Guidance for HSE Inspectors. “poor information in = poor information out”

Example CFD projects for Smoke Control:-

Future?

Future: stacker systems?

QUESTIONS?

Introduction to Design of Car Park ventilation using JetFans & CFD analysis as QCD

Presented by Paul Mason Business Development Manager Soler & Palau

Technical paper H Morgan:- http://www.bse.polyu.edu.hk/researchCentre/Fire_Engineering/summary_of_output/journal/IJEPBFC/V6/p.53-71.pdf