Preparation of HVAC Ducting Layout

WORK INSTRUCTION SEI-HC-PS-W400 INSTRUCTION FOR PREPARATION OF HVAC DUCTING LAYOUT

Rev. Date

: 01 2014.02.03

SAMSUNG ENGINEERING INDIA

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PURPOSE: This document defines the process of preparing HVAC ducting layout with respect to ITB specification and good engineering practice.

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SCOPE: This Work Instruction indicates basic technical requirements to design HVAC Ducting Layout.

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REFERENCES: • • • • • • •

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Civil, Structure and Architecture drawing. HVAC air flow data. HVAC equipment schedule. False ceiling & floor drawings. Architectural Reflected ceiling plan (RCP) ITB specification. Code and standard consideration.

DEFINITIONS: RCP BOD IDC IFA IFC ASHRAE SMACNA

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Reflected ceiling plan Bottom of duct Inter discipline check Issued for approval Issued for construction American Society of Heating, Refrigerating and Air Conditioning Engineers Sheet Metal and Air Conditioning Contractors National Association.

INSTRUCTIONS:

5.1 The HVAC duct routing, sizing, and levelling (BOD) to be decided based on the ITB specification, good engineering practice (ASHRAE & SMACNA standards) maintainability, constructability and the space available in the building. Ducting layout to be prepared based on constant friction method. The air velocity consideration as follows. 8-10m/s in plant room 6-8m/s in main ducting

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4-6m/s in branch ducting The aspect ratio of duct should be less than 1:4. The size of duct can be customize as per space limitation.

5.2 Fittings Duct fittings selection should be based on ITB requirement & good engineering practice. General fittings for HVAC ducting:•

Gas tight Damper:- To prevent outsides hazardous gas enter as fresh air in the system, Gas tight damper require in the fresh air inlet line.

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Volume control Damper: - VCD to be installed to control volume of air in every branch duct and as well as terminals.

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Fire Damper: - Fire Damper to be installed in ducting that crosses any fire rated wall or plant room wall to prevent fire to spread.

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Duct Heater: - Duct Heater to be installed in supply duct for heating of air.

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Sound Attenuator: - Sound attenuator shall be selected to maintain desire room noise level inside the room.

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Diffuser, Grille etc: - Grille, diffusers are used to distribute required air in side the room.

5.3 Routing and Bottom of Duct Duct routing and BOD of duct should be co-ordinated with all building services, layout and space availability.

5.4 Insulation and support Insulation and support of duct to be decided based on ITB specification, HVAC typical drawings and good engineering practice.

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5.5 Access Door in Duct Access doors to be provided on all required location for easy access to duct and fittings for operation and maintenance.

5.6.

Project Phases

5.6.1 IDC Information (layout Dwg.) to be given to other discipline (CSA, Electrical, Instrumentation, Piping layout etc.) for comments and considerations. 5.6.2 IFA Incorporating IDC comments in layout, the drawing to be issued for approval to Client, Consultant and other discipline. 5.6.3 IFC Approved layout to be issued to PMC and Client for approval to proceed construction activities.

6. ATTACHMENTS: 1. Reference HVAC Ducting layout

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7. REVISION HISTORY

No.

Date

Page

Reason for Revision - Company Standard Document Registration of Internal Document - Department

: Piping Speciality-HVAC

Prepared by : Chandan Bhattacharjee 00

2013. 06. 14

New Issue Reviewed by : Pradeep Kumar Suman Approved by : Rakesh Kumar

- Department

: Piping Speciality-HVAC

Prepared by : Chandan Bhattacharjee 01

2014. 02. 03

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Reviewed by : Pradeep Kumar Suman Approved by : Rakesh Sharma

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