Ordinary heating, ventilating, and air conditioning duct systems read air pressures at 0. A practical approach to design, implementation, connolly, t. No part of this work may be reproduced or used in any form or by any means graphic, electronic, or mechanical, including photocopying. Duct systems are becoming a serviceable maintenance item in commercial buildings due to indoor air quality iaq issues, and the. Nonresidential cooling and heating load calculations 19. Principle of duct design in hvac systems cedengineering.
From ashrae fundamentals handbook, the following equations may be used to convert rectangular and flat oval ducts to and from round. Duct sizing and construction tables according to smacna pdf. Duct sizing and construction tables according to smacna. Designing a duct system is important but there are a few critical steps that come first. Number one is the heating and cooling load calculation using a protocol like accas. Put your presentation title or confidentiality info here. Jan 29, 2020 duct design is a key component of energy efficient hvac system performance. The length of duct used for design purposes that includes the. Number one is the heating and cooling load calculation using a protocol like accas manual j or the ashrae handbook of fundamentals. Lowvelocity ductwork design is very important for energy efficiency in air distribution systems. More available in the ashrae handbook or smacna obtain other.
The air duct distribution network is an important component of hvac installations, helping to significantly. Compliance to the design manual, which promulgates minimum performance design standards for va owned and leased. P total the total pressure loss across the duct fitting k. Ashrae fundamentals ip ch 21 duct design engineering360. Duct testing requirements duct leakage must meet one of the following.
Home pdf hvac ducting principles and fundamentals free pdf course. This document is not a procedural stepbystep set of instructions on how to create a duct design. Duct design fundamentals static pressure ps measure of the static energy of air flowing air which fills a balloon is a good example of static pressure equally exerted in all directions the atmospheric pressure of air is a static pressure 14. We encourage engineers, designers, specifiers, and manufacturers of duct system components to get. The latest edition of an ashrae standard may be purchased from the ashrae web site. Insulation can also be installed on the inner wall of the duct duct liners, as glass wool duct wraps or duct slabs faced with a glass matting or mesh providing acoustic insulation and strengthening the inner face of the duct. The procedures of residential hvac design see figure 1 are covered in detail by a series of. Ashrae american society of heating, refrigerating and airconditioning engineers.
Duct design manual is intended to be used in conjunction with the american society of heating, refrigerating and air conditioning engineers, inc. Lowvelocity design will lead to larger duct sizes, but it may be worth since, doubling of duct diameter. The level 2 duct design tdp will present many areas of design enhancement, such as smacna duct construction standards, duct design code requirements, fitting selection using loss coefficients. Duct design fundamentals static pressure ps measure of the static energy of air flowing air which fills a balloon is a good example of static pressure equally exerted in all directions the atmospheric. As is the case with upperroom uv installation design, the design parameters for uvc in induct applications are not simple because of some uncertainty in. This manual provides the hvac system designer detailed. This 2017 va hvac design manual for the department of veterans affairs va healthcare facilities is the only detailed design requirements manual for va. Vav systems are the most common hvac system for commercial buildings, but. Chapter 19 of the 2016 ashrae handbookhvac systems and. Duct system design guide first edition 2003 mcgill airflow corporation mcgill airflow corporation one mission park groveport, ohio 43125 duct system design i notice. Duct systems are becoming a serviceable maintenance item in commercial buildings due to indoor air quality iaq issues, and the proper quantity, size, and location of duct access panels require more definition in new construction design documents. Chapter 19 of the 2016 ashrae handbookhvac systems and equipment examines duct construction and presents construction standards for residential, commercial, and industrial hvac and exhaust systems.
Why duct design is important the efficiency of air distribution. Related commercial resources chapter 35 duct design bernoulli. Wraps incorporate an aluminium foil facing that acts as a vapour barrier. Design cfm 4 cfm 6 cfm 8 cfm 10 cfm 12 60 6x4 60 4x6 90 4x8 120 4x10 150 4x12 90 8x4 110 6x6 160 6x8 215 6x10 270 6x12 120 10x4 160 8x6 230 8x8 310 8x10 400 8x12 150 12x4 215 10x6 310 10x8 430 10x10 550 10x12 180 14x4 270 12x6 400 12x8 550 12x10 680 12x12. Deficiencies in duct design can result in systems that operate incorrectly or are expensive to own and operate. The fourth edition of hvac systems duct design presents the basic methods and procedures required to design hvac air distribution systems. This has included active participation in technical and standards committees for professional organizations that serve the hvac industry. The fundamentals of duct system design mcgill airflow. Highvelocity hv duct systems are characterized by air velocities in the range of 2500 to 3500 fpm. Duct design quick introduction duct sizing tools and methods recommended duct velocities and noise effects. In this chapter, system design and calculation of a systems frictional and dynamic resistance total pressure to airflow are considered. Youve got to know how much heating and cooling you need for each room in btuhr. Duct design clicking on a companys name will take you to their web site.
Fellow ashrae 0 f the three duct design procedures recommended by the 1997. With rightcommduct, compute duct and fitting size based on air flow with appropriate velocity limits, and let the software calculate the required fan pressure and total air flow for you. Duct design is a key component of energy efficient hvac system performance. Residential cooling and heating load calculations 18. Download hvac duct construction tables according to smacna and rule of thumbs pdf. Free ductwork tables for sizing and construction of hvac air ducts. Starting with the original authors suggested thought process for analyzing typical problems, the reader is then exposed to a buzzword of our time.
Ashrae 90571 design guide for air terminal units selection, application, control, and commissioning published by ashrae on january 1, 2018 preface air terminal units play an important role in the. In addition, the physical parameters of the duct, duct airflow, and uv installation have the potential to affect both the irradiance and the microorganisms response to it. Install duct systems in compliance with nfpa 90a installation of air conditioning and venting systems. Chapter 22, pipe design, has a new title and now incorporates the content of its sister chapter, pipes, tubes, and fittings, from hvac systems and equipment. Deficiencies in duct design can result in systems that operate incorrectly or are expensive. This has included active participation in technical and standards committees for professional organizations that serve the hvac industry, such as ashrae, astm, amca, and smacna. Related commercial resources ashrae handbook fundamentals chapter. The basic fluid flow equations are not included here, but may be found in the ashrae handbook. Chapter 22, pipe design, has a new title and now incorporates the.
American society of heating, refrigerating and air. More available in the ashrae handbook or smacna obtain other duct fittings pressure losses from manufacturers such as duct heaters, dampers, filters, grilles, coils, etc calculated by the following formula derived from bernoullis. It does not present official positions of the society nor reflect society policy. This information should be consulted to ensure that the proper type and location of duct system is selected for the structure in question. Design cfm 4 cfm 6 cfm 8 cfm 10 cfm 12 60 6x4 60 4x6 90 4x8 120 4x10 150 4x12 90 8x4 110 6x6 160 6x8 215 6x10 270 6x12 120 10x4 160 8x6 230 8x8 310 8x10 400 8x12 150 12x4 215 10x6 310. Comply with ashrae fundamentals handbook and ashrae systems and equipment for design and fabrication of ductwork. Our manual d calculation service, is a complete custom duct design for your residential project. Comply with ashrae fundamentals handbook and ashrae systems and equipment for design and. Clicking on a companys name will take you to their web site. Fellow ashrae 0 f the three duct design procedures recommended by the 1997 ashrae handbookfundamentals, only the tmethod incorporates lifecycle cost.
More available in the ashrae handbook or smacna obtain other duct fittings pressure losses from manufacturers such as duct heaters, dampers, filters, grilles, coils, etc. It delivers an schematic drawing of the duct system. We encourage engineers, designers, specifiers, and manufacturers of duct system components to get involved at the society level and contribute to our increase of knowledge and understanding of duct design. Lowvelocity ductwork design is very important for energy efficiency in air. Rightcommduct is a fast, easytouse commercial duct sizing and calculation software that takes full advantage of ashraes precision. Hvac ducting principles and fundamentals free pdf course. This information should be consulted to ensure that the. Further considerations duct sizing methods there is no single duct sizing method that will inherently give the best duct design. Using the complete builtin ashrae database of ducts and fittings allows for accurate commercial duct design to ensure the proper product for the job.