General Aim
Scope of works Methodology
I. Duct Installation Works 1. Air Duct Connection 2. Air Duct Seal
3. Air Duct Insulation
II. Air Devices Installation Works
1. Volume Dampers (VD), Volume Control Dampers (VCD), Fire Dampers (FD). 2. Diffuser, Grille
3. Plenum Chamber, Silencer Chamber 4. Flexible Duct, Canvas Joints
5. Louver, Access Door, Outdooor Hood
General:
Items: - The Method Statement for Air Distribution Installation Works.
Aim:
The aim of works is to describe mechanical works associated with installation of Air Distribution Installation Works and to ensure compliance with contract requirements, specification and quality control.
Scope of Works:
The scope of work for this method statement shall include all the Ductworks for the SAIGON M&C TOWER Project.
Methodology:
I. Duct Installation Works:
Table1: Rectangular Duct Thickness Schedule
1. Air Duct Connection:
Table 2: Regulation for air duct connection Schedule
Corner Angle Duct Connection Companion Angle Duct
Less than 600 (mm) C , TDC NA 601 to 1500 (mm) TDC NA 1501 to 2500 (mm) NA Flange-40x40x3.0mm Duct size largest dimension (mm) Over 2500 (mm) NA Flange-40x40x4.0mm Maximum Spacing (mm) 1100 1200
Size of Bolt & Nut (mm) 8 mm 8 mm
Diameter (mm) 3.2 mm 3.2 mm
Rivet Maximum Spacing on
Center (mm) 65 mm 65 mm
Largest Dimension (mm)
Duct Size (L max) Up to 400 600 800 ~ 1250 1600 ~ 2500 Above 2500
Table 3: Support, hanger, spacing schedule Duct size Less than
400 400 ~ 999 1000 ~1999 2000 ~ 2500 Over 2500 Angle steel V-30x30x2.5 V30x30x2.5 V-40x40x3 V-50x50x3.5 U-80x38x3.5 Round bar 2 x Φ8 2 x Φ10 2 x Φ10 2 x Φ10 2 x Φ12 Hanger Max. pitch L 3000 3000 2500 2500 2500 Angle steel V-30x30x2.5 V30x30x2.5 V-40x40x3 V-50x50x3.5 U-80x38x3.5 Vertical support
Max. pitch L One point for each floor
1.1 Duct size over 1500mm:
) For duct size largest dimension over 1500mm show be as Figure 01:
) Detail A show be as Figure 02, Figure 03:
Figure 01: Typical duct connection detail (using flange joint)
Figure 02: Detail of bolt spacing for flange joint 100
Angle steel flange (see table 02) Bolt hole 8mm Sealed 100 100 Concrete slab Air Duct Detail A L ≤ 1200 Hanger rod M10 Angle steel (see table 3) Anchor bolt W
1.2 Duct size under 1500mm:
) For duct size largest dimension under 1500mm show be as Figure 04
) Detail B show be as Figure 05, Figure 06, Figure 07
Figure 05: Detail of Cross Aim Brace Spacing Figure 03: Detail of connection angle for flange
Figure 4: Branch duct connection detail (using Transverse Duct Connector (TDC) joint)
A ≤ 150 mm B ≤ 200 mm 100 mm ≤ C ≤ 150 mm C C B C A B C A 4 holeΦ10 Air duct
Cross aim brace W Air flow Air flow L = 0.25W; L≥150mm L Main duct Detail B Branch duct
Change between section Air flow Rivet 3.2mm 5mm thk
Washer Rubber gasket
Width: 25mm, 5mm thk
Air Duct
Angle steel flange (see table 02) Bolt & Nut 8mm
Table 4: Size, Thickness and Spacing of TDC Joint Schedule
Duct Size largest dimension (mm) Less than 700 700~1200 1200~1500
Size of TDC Duct End (minimum) (mm) 30 30 30
Thickness of TDC Corner (minimum) (mm) 1.2 1.2 1.2
Thickness of Cross Arm Brace (minimum)(mm) 1.0 1.0 1.0
Maximum Spacing (mm) 1100 1100 1100
Max 1100
Bolt M10 Cross Aim Brace
(see table 4)
Air Duct TDC Corner (see table 4) Figure 06: Cross Aim Brace detail
Bolt M10 TDC corner 1.2mm thk TDC duct end (see table 4) Rubber gasket (see figure 08) Nut M10 Nut M10 TDC flange Rubber gasket (see figure 08)
Rubber gasket (see figure 08)
Figure 07: Typical TDC assembly detail Air duct Corner plate
(see detail)
) Note:
? Support, hanger will be concerned on method statement of M&E Support System Installation Work: ME - REE - T+ - MS – G+ - GEN - 003
2. Air Duct Seal:
50 Seal TDC joint Bolt hole 10mm Air Duct 50
Angle flange joint Bolt hole 8mm
Seal
Air Duct
Figure 09: Position of Seal for TDC Joint
Figure 10: Possition of Seal for Angle Flange Joint Bolt hole 8mm
Rubber gasket Width: 25mm
Thickness: 5mm 15-20mm
3. Air Duct Insulation:
Table 5: Duct Insulation Specification Schedule
Applicable scope Material Type Density Thickness
Supply air duct 48kg/m3 25mm
Return air duct Glasswool Blanket 48kg/m3 25mm
Smoke exhaust duct Rockwool Board 60kg/m3 50mm
Supply air chambers and sound attenuation fittings
Glasswool Blanket 48kg/m3 50mm
Figure 11: Possition of Sealant for Duct Seam
Figure 12: Typical smoke exhause duct insulation detail Seam Board insulation 50mm
(see table 5)
Alu. Sheet Cladding (if any) Metal clips Air duct Pin Φ1.6mm (see figure 15) Adhesive
Attached Alu. Tape (Width 50mm)
Seal (Inside Only) Air Duct
(Non-flammable) Metal clip Alu. foil facing
Alu. sheet cladding
Rockwool for smoke exhaust duct Glasswool for AC duct
Air duct
` Pin Φ1.6mm (see figure 15)
Figure 14: Insulation detail for supply air chambers and sound attenuation fitings Figure 13: Ducting insulation layer detail
Pins Φ1.6mm (see figure 14)
Metal clips Air duct
Max. 300mm Max. 300mm
Figure 15: Shape & distance of pins
Metal clip Pin Φ1.6mm Insulated duct Bare duct Max. 300mm Max. 300mm
Page 11
Figure 17: Detail of typical insulation for diffuser box 50mm
50mm
Figure 16: Typical insulation menthod for TDC joint & flange joint Plan view Ceiling Glasswool 25mm thk (outside duct) Aluminum tape 25mm Glasswool 25mm thk (outside duct) Glasswool 25mm thk
(inside diffuser box)
Screw Air flow Chamber box Front view TDC joint 25mm Metal slip Glasswool 25mm thk
Attached alu. tape 25mm 25mm
Flange joint
Pin Φ 1.6mm
Attached alu. tape 25mm TDC or Flange joint
Glasswool 25mm thk Alu. Tape 50mm
25mm
II. Air Devices Installation Works:
1. Volume Dampers (VD), Volume Control Dampers (VCD), Fire Damer (FD):
Table 6: Quantity of hanger rods for Fire Damper
Rectangular Duct Spiral Duct
Duct size or Diameter (mm) Less than 300 Over 300 Less than 300 Over 300
Quantity of hanger rods (nos) 2 4 2 4
Figure 19: Detail of setting damper
Figure 18: Detail of typical insulation for grille (VHS type) Glasswool 25mm thk (outside duct) Wall Screw Frame Tapping Air duct TDC joint Air flow L = 8D
D: diameter of air duct
Concrete foundation L D Air Fan VD VD Air duct Concrete slab
Anchor bolt Concrete floor slab
Angle steel Insulation 25mm Rubber pad Bolt M8 Wall Fire damper Vertical duct Wall Concrete floor slab
Fire damper VCD Access door FD V-Angle steel Rockwool 50mm Duct elbow Insulation 25mm V-Angle steel Anchor bolt Hanger rod Vertical duct Bolt M8
Figure 20: Typical damper installation detail PLAN VIEW
2. Diffusers, Registers:
Ceiling
SUPPLY AIR CHAMBER BOX
Glasswool 25mm thk
Glass wool 25mm thk Insulation (outside) Opposed blade damper
Glass wool 25mm thk Insulation (outside)
Insulation (inside)
(if any)
Figure 21: Example of connection with chamber & duct Connection with chamber box
H, W: Dimension of Diffusers opening size for ceiling (mm) d : Diameter of flexible duct (mm)
Flexible
K = 150 ~ 300mm
D＋50mm
Connection with Duct
Figure 22: Detail of typical installation for supply air diffuser
K W×H Ceiling Air duct W＋50mm H＋50mm D W×H K Ceiling Chamber box D Flexible H＋50mm 100mm or over
RETURN AIR CHAMBER BOX
Ceiling
Screw Glass wool 25mm thkInsulation (outside) Glasswool 25mm thk
Insulation (inside)
EXHAUST AIR CHAMBER BOX
Opposed blade damber
Ceiling
Screw
(if any)
3. Plenum Chamber, Silencer Chamber:
? Sound Absorber for Chamber shall be used glasswool 50mm thk, 48 kg/cm3 density. Table 7: Galvanized steel sheet thickness for Chamber
Longest Dimension of Chamber (mm)
Chamber Size (L max) (mm) Less than 800 800 ~ 1500 1500 or Over
Steel Sheet Thickness (mm) 0.8 1.0 1.2
Figure 24: Detail of typical connection for exhause air grille Figure 23: Detail of typical installation for return air grille
Figure 25: Silencer Elbow Chamber Detail
Figure 26: Silencer Chamber Detail
Sound Absorber by glasswool 50mm thk R A L A Silencer Elbow A B Silencer Chamber Sound Absorber by glasswool 50mm thk Detail D Detail E Detail E Pin Φ 1.6mm GI sheet cover 0.6mm thk 25~50mm Air Duct Sound Absorber by glasswool 50mm thk
4. Flexible Duct, Canvas Joints a) Flexible Duct: Bolt M6 AIR DUCT FLEXIBLE DUCT Screw 3.2Ø G.I.sheet 0.6mm thk Steel band Ceiling
SUPPLY AIR CHAMBER BOX
Opposed blade damper Glass wool 50mm thk
Insulation (outside) G.I.sheet 0.6mm thkSteel band Glasswool 25mm thk
Insulation (inside)
Insulation (outside)
(if any) Glasswool 25mm thk
Figure 27: Chamber Jointing Detail
Figure 28: Detail of typical connection between flexible duct & chamber box PinΦ1.6mm 100~150mm 75mm 25~50mm Sound Absorber by glasswool 50mm thk
b) Canvas Joints:
RETURN CHAMBER BOX
Ceiling Canvas Flange joint (refer to detail G) Glasswool 25mm thk Insulation (outside) Glasswool 25mm thk Insulation (inside) AIR DUCT Screw
Figure 29: Canvas Joint Detail
Figure 30: Detail of typical connection between canvas & chamber box L = 200 ~ 250 (mm)
Detail F
Galvanized steel sheet ( same as duct thickness)
Angle steel flange Rubber gasket (width:5mm)
Cuff 5mm or more
Rivet 3.2mm Bolt and nut M8
Canvas Joint Washer Air duct L Flange joint Air duct Air duct Duct canvas Detail F
5. Louver, Access door, Outdoor Hood: a) Louver:
Figure 31: Typical Louver Installation Detail
Concrete slab Louver Chamber box Anchor bolt Access door (see figure 32) Hanger rod
Mortar Grout Anchor bolt
Wall
500mm
Angle steel (see table 3)
b) Access door: Sach lock Air duct Aluminium Screw 3.2Ø Steel plate Steel plate Sach lock Aluminium c) Outdoor Hood: .
Figure 33: Typical Outdoor Hood Installation Detail Chamber box Outdoor hood GI sheet cover 0.6 mm thk Air duct Wall Insect Screen (if any) Mortar Sealant Rockwool 60kg/m3 Screw
