Smoke Management Calc for Car Park

ECG Engineering Consultants Group PROJECT NAME: Nozha City Centre.

DATE: MAY-2007

PROJECT NO.: 1127

COMPUTED BY: A.Salah SMOKE MANAGEMENT DESIGN CALCULATION SHEET

Area Served:

Car Park

Ventilation Type:

Mechanical Ventilation Fans

Brief description:

Exhaust through high temperature rated fans. Fresh Air make-up through Ramps and slab openings.

Design Parameters: Fire Size

=

3x3

Fire Area

=

9m

Heat Rate ( Qr)

=

Heat Production (Q)

=

278 kw/m 2502 kw

2

Perimeter ( P )

=

12 m

Smoke Layer Height (Y)

=

2.5 m

2

Smoke Layer Depth (Db)

=

1.5 m

Air Specific Heat ( Cp)

=

1.01 kj/kg.k

Outside Air Temp. (To)

=

30 deg.c

= =

0.188 x P x Y 0.188 x 12 x 3.95

=

8.918 kg/s

(303 k)

Calculations Min. Smoke Flow Rate (Mf) = Temperature Rise (Tr)

=

Q / (Mf x Cp)

=

=

277.8 Deg.c

=

To + Tr

=

=

307.8 deg.c

=

Mf x Tc / (1.2 x To)

=

8.918 x 581 / (1.2 x 303)

=

14.24 m /s =

=

30,182 CFM

Max. Smoke Temp. (Tc)

Air Volume Flow rate (Ma)

1.5

( 581 k )

3

Note: As per ANSI/ASHRAE standards 62.1.2004 Recommendation provide 3.7 lit/sec/m2 For 12000 m2 cfm = 12000 x 3.7 x 2.1 = 93.240 cfm. Shall be divided into 5 exhaust fans two speed fire protected each one is 20 000 cfm for ventilation. As per NFPA part 92B Car parking area divided into 5 fire zones 2500 m2 each , Total exhaust 150,000 cfm. 3

Direct drive two speed smoke exhaust fans of 14.1 m /s (30,000 cfm) rating shall be provided in each parking zone , o Fire rated for 300 C for 1 HR. Motor and Bearing shall be out of air stream. Make up fresh air shall be supplied from Ramps and Slab opening.