Design the duct system using a velocity method, and b equal friction method. Ansismacna 0062006 hvac duct construction standards. The most popular duct sizing method equal friction is covered in detail. The individual room controls depending on the hvac system design. The purpose of residential ductwork design is to properly distribute the airflow, produced by your heatingcooling system, to your house. Download hvac duct construction tables according to smacna and rule of thumbs pdf. Material thickness astm type duct end treatment galvanized 26 18 gauge a653 g60g90 48, 60, 72 paint grip 24 18 gauge a653 a60 60 pvs 24 18 gauge a653 4 x 1, 4 x 4 60 raw both ends aluminum. Two duct design experts, jjw bill siganto and murray mason provide a wealth of information on the topic. To account for all the necessary factors, many professionals use a tool called acca manual d. The course concludes with the basic instructions for filling out a manual d speedsheet. Put your presentation title or confidentiality info here big picture. Duct system design guide first edition 2003 mcgill airflow corporation mcgill airflow corporation one mission park groveport, ohio 43125 duct system design i notice. A perfect tool for the designer or troubleshooter who is.
Generally at the time of designing an air conditioning duct system, the required airflow rates are known from load calculations. Understanding basic residential ductwork design please note. Duct sizing and construction tables according to smacna pdf. The ashraefundamentals handbook contains hvac design criteria for most countries around the world. Jul, 2016 accuduct is an easy acca approved manual d duct design program. No part of this work may be reproduced or used in any form or by any. Duct size manufacturing costs duct systems pressure losses operation cost. Introduction the design of duct systems is an important factor for.
Increased friction rate in compressed flexible duct. The program allows the user to input multiple sections and view the overall results. Principle of duct design in hvac systems cedengineering. Download limit exceeded you have exceeded your daily download allowance. This calculation is the staging point for all aspects of the heating and air conditioning. Temperature at the inlet of the duct 323 k outside temperature 300 k. The purpose of this project is to develop a costeffective design for moving the hvac system into conditioned space. Highvelocity hv duct systems are characterized by air velocities in the range of 2500 to 3500 fpm. Duct design duct design services hvac design manual. According to the us department of energy, the average hvac duct.
Decisions are made about the types of systems to be used. Be installed so that the static air pressure drop across the han. Rush service available in a case per case basis for an addtl. Offers the hvac system designer and installer detailed information on duct design, materials and construction methods. Ratna kumari and others published design and drafting of hvac, central air conditioning system for an office building find, read and cite all the research you need on. Ordinary heating, ventilating, and air conditioning duct systems read air pressures at 0.
Proper duct design is critical for any home for the comfort systems to deliver promised comfort levels. Duct design free download as powerpoint presentation. Fundamentals distribution systems 1 introduction this technical development program tdp covers the fundamental principles of duct sys tem design for commercial building applications. Duct design duct design services hvac design manual j. Take the velocity of air in the main duct a as 8 ms for both the methods. Optimization of heat transfer through rectangular duct. Duct sizing, june 1977 2 airah application manual duct design da3, 1987 3 ashrae handbook of fundamentals 2001 4 smacna hvac systems duct design 3rd edition 1990. In addition to the basic engineering guidelines for the sizing of hvac ductwork systems, the manual also provides related information on economics of duct systems, duct system layout, pressure losses, fan selection, duct. New duct sizing chart purchase your hvac equipment. Fundamentals of hvac controls course content fundamentals of hvac controls the application of heating, ventilating, and airconditioning hvac controls starts with an. 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.
Book by sheet metal and air conditioning contractors national association, 2006. Lowvelocity ductwork design is very important for energy efficiency in air. The results are analyzed to compare duct design methods, and the effects of several factors that influence optimal design are investigated. Procedures for hvac system design and installation criteria for a quality hvac system an hvac system should. For most single family work, the insulation must meet the levels shown in the following table. Integration of hvac system design with simplified duct distribution building america research has provided critical guidance for designing hvac systems in highperformance homes with low heating and cooling loads. Hvac design impacts 1st construction costs comfort indoor air quality building durability. This document is not a procedural stepbystep set of instructions on how to create a duct design. A duct system is an assembly whose primary function is to convey air between specified points. Compliance to the design manual, which promulgates minimum performance design standards for va owned and leased. Duct sizer software calculates the friction loss in a section of duct. Today ill start with what you do in the hvac design process before you get to the duct design phase manual d as well as the physics of air flow when its constrained by ducts. University of colorado boulder, co, usa overview system description secondary hvac systems air distribution room diffusers and air terminals duct design fan characteristics air handling units water distribution cooling coils pipes and pumps primary hvac systems electric chillers. Residential hvac duct drawing hvac design, air conditioning.
Properly designed duct systems can maintain uniform temperatures throughout the house, efficiently and quietly. In addition to the basic engineering guidelines for the sizing of hvac ductwork systems, the. Disclaimer of warranties a the sheet metal and air conditioning contractors national association smacna provides its product for informational purposes. Once all the system variables have been decided, your hvac design professional can determine the most efficient ductwork design layout and calculate the correct duct size. The basic principles of duct design, part 1 energy vanguard. This 2017 va hvac design manual for the department of veterans affairs va healthcare facilities is the only detailed design requirements manual for va.
Manual q is your onestop reference book on the lowpressure, lowvelocity systems used in small and midsize commercial buildings. Residential hvac duct drawings initially for your hvac duct drawing you should start with a simple sketch. The efficiency of air distribution systems has been found to be 6075% or less in many houses because of insufficient andor poorly installed duct insulation and leaks in the duct system. Where necessary circular equivalent of a flat oval. Design options for hvac distribution systems overview the objective of an hvac heating, ventilating, and airconditioning system is to control the temperature, humidity, air movement, and air cleanliness, normally with mechanical means, to achieve thermal comfort. Manual q commercial low pressure low velocity duct system. Lowvelocity design will lead to larger duct sizes, but it may be worth since, doubling of duct.
Consequently, the total pressure or total energy of air flowing in a duct system is generally equal to the sum of the static pressure and. Ill follow that up with articles on the process we use in designing duct systems, including available static pressure, equivalent length, and choosing fittings. Duct sizing calculations include constant pressure drop, constant velocity, and static regain. Refer to the links on the left for more information. Hvac duct design services, ductwork drawings india mep. To use this chart, convert a rectangular duct with sides of 17 inches by 16 inches, respectively. Modified equal friction, incorporating many of the benefits of. Below is a simple model for determining duct sizes. Duct design duct flow hvac free 30day trial scribd. This 3hour hvac training online video series provides guidance on how to properly use a friction chart andor accas duct slide rule values for sizing duct in the field. Call today and get complete information and a free analysis. Figure 3 is a sketch of an air conditioning cycle plotted on a psychrometric chart. Lowvelocity ductwork design is very important for energy efficiency in air distribution systems.
In addition to the basic engineering guidelines for the sizing of hvac ductwork. Hvac ducting principles and fundamentals a pdh online. Mep design services members are well versed with the technicalities and standards that are must for a good quality hvac designs. The process begins with a roombyroom manual j heat lossgain calculation. Table 3 is based on equation 24 heyt and diaz 1975, the the section on hvac duct design procedures. 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 210 16x4 320 14x6 490 14x8 670 14x10 800 14x12 240 18x4 375 16x6 580 16x8 800 16x10 950 16x12 270 20x4 430 18x6 670. The types of fittings to be used based on the designers calculations of fitting losses i. Design of flexible duct junction boxes current standards ashrae 2012 hvac systems and equipment, box plenum systems using flexible duct constrains box width to 23x entrance width constrains box length to 2 x box width flat pressure loss. Wraps incorporate an aluminium foil facing that acts as a vapour barrier. Be properly sized to provide correct air flow, and meet roombyroom calculated heating and cooling loads. Poor or no duct design results in rooms and floor that are too hot and too cold. Duct and pipe insulationis required for all hvac ductwork and pipes in unconditioned spaces, as indicated in ecccnys 503.
Design constraints for vav duct systems are added as penalty terms to the objective function for any violation of the constraints. Heating, ventilation, and air conditioning design strategy. In this tutorial, we examine the simplicity of creating and starting a duct design while incorporating a load from accuload. This manual provides the hvac system designer detailed information on duct design and u. Apply to designer, mechanical designer, custodian and more. Corporate headquarters sheet metal connectors, inc. Smacna cad standard second edition v notice to users of this publication 1.
Manual q gives you timesaving quick fitting loss tables and a complete set of fitting loss tables compiled from the ashrae and smacna handbooks. Lowvelocity design will lead to larger duct sizes, but it may be worth since, doubling of duct diameter. This calculation is the staging point for all aspects of the heating and air conditioning system which will follow. Related commercial resources ashrae handbook fundamentals chapter.
Find out how to improve your air conditioning with better duct design, and why you need hvac experts involved early in your renovation process. Drafting features include singleline and doubleline 2d ductwork with automatic fittings and 3d ductwork. The nelder and mead downhill simplex method nelder and mead 1965 is applied to search for a continuous design solution for the constrained duct design problem, and a penalty approach for. There are exceptions for return ducts in basements and ducts or pipes inside hvac equipment. Rightsizing of a heating, ventilation, and airconditioning hvac system is the selection of. Heat conduction and thermal resistance for steady state conditions and one dimensional heat transfer, the heat q conducted through a plane wall is given by. Table 1 in accas manual j lists design con ditions for locations in the u. Because of the complexity of designing duct systems, we highly recommend using the acca manual d for sizing ductwork, or consulting a professional hvac contractor. Raw duct is fabricated for proprietary duct connection systems. Duct leakage air tightness how to approach manual j. Friction losses furnace no scale supply fan coil or furn ace r. The fourth edition of hvac systems duct design presents the basic methods and procedures required to design hvac air distribution systems.
Smacna cad standard sheet metal and air conditioning. This information should be consulted to ensure that the proper type and location of duct system is selected for the structure in question. From here you will begin to notice obstructions that your ductwork must get around, and different ideas for duct routing, which will work better for firdowns and final finish. You can twist an electrical wire into a pretzel and it will still transmit electricity. Design master hvac is an integrated hvac building design and drafting program that runs on top of autocad. For full stepbystep instructions on ducting system design, download the pdf below. Air flow problems have plagued the hvac industry for years. Fibrous glass insulated hvac duct systems 4 sheet metal ducts with exterior fibrous glass exterior insulation flexible blanket fibrous glass duct wrap insulation is designed for application to the exteriors of commercial and residential sheet metal heating, ventilating, and airconditioning ducts and plenums operating at temperatures between 40. Principle of duct design in hvac systems muli anto. In part 2, the vav duct design procedure is fully developed and applied to several vav duct systems with different parameter values.
The model applies to system up to 60 feet from unit to register. Most residential and commercial building hvac design is based on low to medium pressure systems. A duct system may contain ducts under positive and negative pressure. Integration of hvac system design with simplified duct.
Free ductwork tables for sizing and construction of hvac air ducts. First, come down the lefthand column until you reach 17 inches. Our questionnaire asks simple stepbystep questions about your application so that we can ensure a proper ductwork design. Download our questionnaire to answer simple step by step questions about your application, use the sketch grid to provide a rough layout of your application with accurate measurements, and submit for a professional cad drawing, parts list, detailed installation instructions, and budgetary quote. The user can choose from three different types of duct construction, and rectangular or round. The table below can be used to compare equivalent diameters for rectangular and round circular ducts, ductwork sizing, friction loss, sheet metal gauges, etc. All information provided in this document is to be used as a guideline only. A comprehensive duct layout indicating sizes, design airflows, pressure class, and routing of the duct system. Duct sizing the main goal of designing hvac duct systems is to use the lowest. The procedures of residential hvac design see figure 1 are covered in detail by a series of. The online store for wholesale hvac contractors webreps is a divison of webreps, llc.
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