Consequently, the total pressure or total energy of air. Were following the manual d protocol for duct design, a standard developed by the air conditioning contractors of america acca. For example, in a variable air volume system, sheet metal ducts with fibrous glass duct liner may be used on the high pressure side if design static pressure exceeds the 2 in. This document is not a procedural stepbystep set of instructions on how to create a duct design. Choosing the rightsized duct is critical to maintain proper air flow in the system. In air conditioning systems the duct is considered a static component of the installation through. Design considerations for commercial kitchen ventilation. Any renovation project should carefully evaluate the age, condition, performance, and code. Air duct components and minor dynamic loss coefficients minor loss pressure or head loss coefficients for air duct. Typical air duct velocities typical air duct velocities in applications like ventilation systems or compressed air systems. View and download fujitsu air conditioner duct type operating manual online. Howard, iii sheet metal and air conditioning contractors national association. Duct systems are designed to properly distribute air throughout a building.
Abstractthe choice of inside comfort design conditions for an air conditioned room or building depends on the physiological considerations and economic factors. 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. Source book for efficient air duct systems in europe 1 introduction one aim of this source book is to increase hvac designer awareness of the important role the ductwork plays with respect to function, costs and energy use of the hvac system. The advantage of a ptac is reduced first cost, the disadvantage is decreased energy efficiency. The course concludes with the basic instructions for filling out a. Ductwork design for most hvac contractors, the mathematics and calculations of good duct sizing and layout are done by applying the accas manuals d residential and q commercial. Once a duct system configuration and preliminary design are completed, different equipment may need to be selected to achieve the proper airflow to satisfy the roombyroom heating and cooling loads.
One disadvantage to locating the air handler in the attic space. The purpose of this project is to develop a costeffective design for moving the hvac system into conditioned space. Source book for efficient air duct systems in europe. For air quantities greater than 4500 ls size duct at 10ms. Rightsize heating and cooling equipment dont forget the ducts air leakage and heat losses from ducts can rob your space conditioning system of its capacity under peak conditions. Hvac systems duct design sheet metal and air conditioning. Provide the reader with a case study on the design and optimisation of an air conditioning ac system. Duct design manual as part of our continuing effort to upgrade the quality of work produced by the heating, ventilating and air conditioning. The purpose of residential ductwork design is to properly distribute the airflow, produced by your heatingcooling system, to your house. Figure 3 is a sketch of an air conditioning cycle plotted on a psychrometric.
Find out how to improve your air conditioning with better duct design, and why you need hvac experts involved early in your renovation process. Simply put, a duct is the channel that carries cooled air from the air conditioning unit through your home, and can also remove warm or stale air. Pdf duct designing in air conditioning system and its impact on. Chapter 7 heating, ventilation, and air conditioning 127 figure 73 air conditioning with the vapor compression cycle the exterior, aircooled condensing unit should be kept free from plants and debris that might block the flow of air through the coil or damage the thin fins of the coil. Apr 12, 2016 measuring velocity pressure, fpm and cfm with a testo 510i manometer and a pitot tube duration. Ducts for central air conditioning can also be used for heating and filtering systems. How to size an air conditioner return air duct hunker. The aim of this research work is to design a central air conditioning system for a 2500 capacity auditorium so that the load calculation in the building conforms to the air. Ventilation systems for ventilation and air handling air change rates, ducts and pressure drops, charts and diagrams and more. 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.
Ductwork sizing, calculation and design for efficiency hvac. In keeping with its policy of disseminating information and providing standards of design and construction, the sheet metal and air conditioning contractors national association, inc. For air quantities less than 180 ls, size duct at 4. To this point in our little series on duct design, weve been calculating intermediate quantitites. This manual provides the hvac system designer detailed information on duct design and u. Computer room units are designed to handle cooling loads which are 100% sensible. Abstractthe choice of inside comfort design conditions for an airconditioned room or building depends on the physiological considerations and economic factors.
Duct leakage air tightness how to approach manual j. Principle of duct design in hvac systems cedengineering. The table below can be used to compare equivalent diameters for rectangular and round circular ducts, ductwork sizing, friction loss, sheet metal gauges, etc. Air flow problems have plagued the hvac industry for years. Guide to hvac design, theory of operation, and primary components. Da03 features detailed guidelines for designing air conditioning ductwork systems. Ansismacna 0062006 hvac duct construction standards. One disadvantage to locating the air handler in the attic space is serviceability. Fujitsu air conditioner duct type operating manual pdf download.
Ducts sizing velocity reduction method the velocity reduction method can be used for sizing air ducts. 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. Duct sizing and construction tables according to smacna pdf. The above cooling issues highlight the need for optimizing duct design especially with respect to suitable shape. When you need any air conditioning, heating, indoor air quality, or commercial hvac services in the surrounding jacksonville, fl area, call ac designs. Also, improper duct installation will impact your air conditioners efficiency and your electric bill. What is a small duct, high velocity air conditioning system. Air conditioner duct type air conditioner pdf manual download. The air handler is designed to remove air from the house, condition it, and supply it back to each room. Our team of nate certified, extensively trained service providers can handle any heating or air conditioning job at your home or commercial property.
The fourth edition of hvac systems duct design presents the basic methods and procedures required to design hvac air distribution systems. The basic principles of duct design, part 1 energy vanguard. Duct design submitted in partial fulfillment of requiredment for the award of the degree of bachelor of technology in mechanical enginneering submitted by md zeeshan x01a0366 sandeep singh x01a0392 zafaryab haider x01a03c2 md rizwan x01a0367. Download hvac duct construction tables according to smacna and rule of thumbs pdf. Small hvac system design guide overview 1 overview this design guide focuses on packaged heating, ventilation and air conditioning hvac syst ems up to 10 tons per unitthe most common hvac systems for small commercial buildings in california. Another aim is to point out the connection and cooperation that is necessary between. This is both a building system designed to keep the environment comfortable for building occupants and the industry that supports these systems. A packaged terminal air conditioner ptac is a small unitary dx system designed for throughwall installation.
The internal face of the duct has either an aluminium coating, a glass mat or fabric layer, depending on the properties required of the duct. Pressures varied significantly with size of box, relative positions of outlets, air velocity and volumetric flow. Duct designing in air conditioning system and its impact on system performance. Below is a simple model for determining duct sizes. Heating, ventilation, and air conditioning design strategy. 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. Narsimha reddy engineering college design of air conditioning ducts submitted in partial fulfillment of requirements for the award of the degree of bachelor of technology mechanical enginneering under the esteemed guide suresh. Free ductwork tables for sizing and construction of hvac air ducts. Tech department of mechanical engineering submitted by md zeeshan x01a0366 sandeep singh x01a0392. Jun 17, 2015 simply put, a duct is the channel that carries cooled air from the air conditioning unit through your home, and can also remove warm or stale air. Design of flexibleduct junction boxes conclusions designers must recognize that junction boxes are cost effective but add more pressure to systems compared to trunk and branch designs. These systems are notorious for consuming more energy than is necessary to properly heat.
Enable the reader to understand the fundamental principles and. Installation of ductwork should comply with smacna hvac duct construction. Lets look at some of the different types of ducts needed for air conditioning. One thing to remember is that you must have enough supply vents vents blowing air out and return vents vent sucking warm air back in the air conditioner. The external face of the duct is faced with a robust reinforced aluminium foil which acts as a vapour barrier and confers air tightness on the duct. The volumetric flow rate of air that will be conveyed through the duct in an air conditioning system is determined by the coolingheat load. Chapter 7 heating, ventilation, and air conditioning. Also, improper duct installation will impact your air conditioner s efficiency and your electric bill. Whereas comfort air conditioning would require about 210 air changeshr, a typical cleanroom would typically require 20 60 air changes and could be as high as 600 for absolute cleanliness.
Design guide for heating, ventilating, and air conditioning systems. Ducts that are not well designed result in discomfort, high energy costs, bad air quality, and increased noise levels. A comprehensive duct layout indicating sizes, design airflows, pressure class, and routing of the duct system. Today we use all that to find out how big the ducts need to be. In order to have a better understanding if these systems, you need to know some of the principles behind hvac design.
Hvac systems heating, ventilation and air conditioning systems design and dimensions. Thus, ter 16 of the 2004 ashrae handbookhvac systems and equipment examines duct construction and presents. Handbook of heating, ventilation and air conditioning. All information provided in this document is to be used as a guideline only. Compact duct duct high static pressure duct 04 06 10 12 14 16 18. Ductwork design principles starting with the basics, lets start at the most elementary level of air flow. This course will discuss the basic fundamentals and principles of air conditioning duct design and layout. Technology fact sheet rightsize heating and cooling equipment. Highvelocity hv duct systems are characterized by air velocities in the range of 2500 to 3500 fpm. Pdf duct designing in air conditioning system and its.
The louvre design distributes air leaving a space between the chassis and the ceiling allowing far and wide air flow distribution. Reasonable kitchen air conditioning design is a balance of spot workstation heatingcooling, occupant ventilation, space. If the ducts are incorrectly sized or laid out poorly, even the most expensive furnace and central air conditioner will underperform. Increased friction rate in compressed flexible duct.
Different types of ducts for central air conditioning. 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. Duct leakage figure 1 can occur on either the supply side or the return side of the air handler as well as in the air handler itself. Lowvelocity ductwork design is very important for energy efficiency in air distribution systems.
Fundamentals of hvac controls the application of heating, ventilating, and air conditioning hvac controls starts with an understanding of the building and the use of the spaces to be conditioned and controlled. Small hvac system design guide new buildings institute. The procedures of residential hvac design see figure 1 are covered in detail by a series of publications produced by the air conditioning contractors of america acca, which in turn. In many residential air conditioning systems, the duct system passes through unconditioned zones, which may have thermally disadvantageous consequences. Hvac design for cleanroom facilities ced engineering. Having a manual s performed is mandatory in most us states to obtain permits for an air conditioning system installation. By enabling ducts to transmit heated or cooled air to occupied spaces at design temperatures, building operating cost is reducedsparing the environment from additional greenhouse gases released into the air. You probably didnt realize that your hvac system and its air duct system is something you need to be thinking about even before the architect has completed the plans. Typical air conditioning equipment is designed to handle cooling loads which are approximately 70% sensible.
Acca is the source of technical expertise in the indoor environment industry. Give an overview of the historical development of the heating and ventilation system and introduction of the air conditioning ac system. Ventilation and air conditioning for design and implementation duct sizing bile duct commercial duct value r6 or r8 commerical building duct r value aluminum duct gauge smacna round duct duct insulation r value. May 25, 2017 the basic principles of duct design, part 1. Smacna, offers this comprehensive fundamental hvac systems.
Design of central airconditioning system for a 2,500. The shorter the duct runs are, the lower the resistance to air flow and the lower the heat gains and heat losses will be. In this video well be learning how to size and design a ductwork for efficiency. Pdf in this paper importance of duct designing has been analyzed which create an impact of system performance. Acca technical manuals are taught by the leading industry schools and vocational programs. Understanding basic residential ductwork design please note. Rightsizing of a heating, ventilation, and airconditioning hvac system is the selection of. The air handler should be located where the shortest duct runs possible are attained.
Nov, 2017 if the ducts are incorrectly sized or laid out poorly, even the most expensive furnace and central air conditioner will underperform. For air quantities greater than 180 ls, but less than 4500 ls. The fundamentals of duct system design mcgill airflow. When warm, humid air comes in contact with the surfaces of. Generally at the time of designing an air conditioning duct system, the required airflow rates are known from load calculations. Our technical manuals cover the complete gamut of design, installation and maintenance for residential and light commercial hvac systems. Lowvelocity design will lead to larger duct sizes, but it may be worth since, doubling of duct diameter. Maximum size of duct or pipe through steel joists k series joists and maximum size of ducts and pipes. The articles referenced here will give you a full and complete. 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 the velocity pressure. It is worth noting that the design of a space conditioning system is an iterative process. Hvac is an acronym for heating, ventilation, and air conditioning.
1433 946 869 875 927 537 1025 797 800 736 896 554 581 1213 623 1104 293 1509 270 551 487 800 1140 1466 192 193 1165 131 440 546 745 1420 1462 1236 276 1386 275 1384 777 1132 1087