Determining Pressure Losses for Airflow in Residential Ductwork

Determining Pressure Losses for Airflow in Residential Ductwork PDF Author: Kevin Douglas Weaver
Publisher:
ISBN:
Category :
Languages : en
Pages :

Get Book Here

Book Description
Airflow pressure losses through rigid metallic and non-metallic flexible ducts were studied and recommendations to improve the rating of flexible ducts were made as part of this study. The testing was done in compliance with ASHRAE Standard 120-1999, Methods of Testing to Determine Flow Resistance of HVAC Air Ducts and Fittings (ASHRAE 1999). Duct sizes of 6", 8", and 10" were tested in a positive pressure, blow-through configuration. An As-Built Test Protocol expands the test configurations specified by Standard 120-1999. Results of the current tests extend the existing ASHRAE/ACCA data for flexible duct which does not include pressure loss data for flexible ducts that are compressed beyond approximately 4%. The data from this study exhibit higher pressure drops than prior ACCA or ASHRAE data. Some configurations exhibit over ten times the pressure loss found in rigid duct or fully stretched flexible duct of the same diameter.

Determining Pressure Losses for Airflow in Residential Ductwork

Determining Pressure Losses for Airflow in Residential Ductwork PDF Author: Kevin Douglas Weaver
Publisher:
ISBN:
Category :
Languages : en
Pages :

Get Book Here

Book Description
Airflow pressure losses through rigid metallic and non-metallic flexible ducts were studied and recommendations to improve the rating of flexible ducts were made as part of this study. The testing was done in compliance with ASHRAE Standard 120-1999, Methods of Testing to Determine Flow Resistance of HVAC Air Ducts and Fittings (ASHRAE 1999). Duct sizes of 6", 8", and 10" were tested in a positive pressure, blow-through configuration. An As-Built Test Protocol expands the test configurations specified by Standard 120-1999. Results of the current tests extend the existing ASHRAE/ACCA data for flexible duct which does not include pressure loss data for flexible ducts that are compressed beyond approximately 4%. The data from this study exhibit higher pressure drops than prior ACCA or ASHRAE data. Some configurations exhibit over ten times the pressure loss found in rigid duct or fully stretched flexible duct of the same diameter.

Airflow in Ducts

Airflow in Ducts PDF Author: Leo A. Meyer
Publisher: LAMA Books
ISBN: 0880690186
Category : House & Home
Languages : en
Pages : 125

Get Book Here

Book Description


Static Pressure Loss in 12", 14" and 16" Non-metallic Flexible Duct

Static Pressure Loss in 12 Author: David Lee Cantrill
Publisher:
ISBN:
Category :
Languages : en
Pages : 93

Get Book Here

Book Description
This study was conducted to determine the effects of compression on pressure drops in non-metallic flexible duct. Duct sizes of 12", 14" and 16" diameters were tested at a five different compression ratios (maximum stretch, 4%, 15%, 30% and 45%) following the draw through methodology in ASHRAE Standard 120 -1999 -- Methods of Testing to Determine Flow Resistance of Air Ducts and Fittings. With the pressure drop data gathered, equations were developed to approximate the pressure loss at a given air flow rate for a given duct size. The data gathered showed general agreement with previous studies showing an increase in compression ratio leads to an increase in static pressure loss through the duct. It was determined that pressure losses for compression ratios greater than 4% were over four times greater than maximum stretched flexible duct of corresponding duct size. The increased static pressure losses can lead to decreased performance in HVAC systems. The findings of this study add to the existing ASHRAE and industry data for flexible duct with varying compression ratios. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/151218

Method of Testing to Determine Flow Resistance of HVAC Ducts and Fittings

Method of Testing to Determine Flow Resistance of HVAC Ducts and Fittings PDF Author:
Publisher:
ISBN:
Category : Air conditioning
Languages : en
Pages : 90

Get Book Here

Book Description


HVAC Duct Design

HVAC Duct Design PDF Author: Charles Nehme
Publisher: Charles Nehme
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 30

Get Book Here

Book Description
HVAC duct is a system of metal or flexible tubes that are used to distribute heated or cooled air throughout a building. They are typically made of sheet metal, fiberglass, or plastic and come in a variety of sizes. They are connected to registers, diffusers, and grilles, which help to regulate the air flow and temperature. Duct sizing is the process of ensuring that the right size of ducts and fittings is used in a ventilation system. This process involves calculating the air volume, velocity and pressure drop of the system, and then selecting the appropriate size of ducts and fittings to accommodate that air volume, velocity and pressure drop. The first principle of HVAC duct design is selecting the right size and type of components. The size and type of components are determined by the desired airflow, static pressure, and other criteria. Proper sizing helps to ensure that the system can adequately heat or cool the space. The components should also be selected based on the desired sound level, ease of installation, and other design considerations. HVAC Ductwork book, HVAC Rectangular Duct, HVAC Duct Design

Handbook of Hydraulic Resistance

Handbook of Hydraulic Resistance PDF Author: I. E. Idelchik
Publisher:
ISBN: 9788179921180
Category : Fluid dynamics
Languages : en
Pages : 0

Get Book Here

Book Description
The handbook has been composed on the basis of processing, systematization and classification of the results of a great number of investigations published at different time. The essential part of the book is the outcome of investigations carried out by the author. The present edition of this handbook should assist in increasing the quality and efficiency of the design and usage of indutrial power engineering and other constructions and also of the devices and apparatus through which liquids and gases move.

HVAC Systems Duct Design

HVAC Systems Duct Design PDF Author: Smacna
Publisher:
ISBN: 9781617210471
Category : Air conditioning
Languages : en
Pages : 0

Get Book Here

Book Description


A Study of Pressure Losses in Residential Air Distribution Systems

A Study of Pressure Losses in Residential Air Distribution Systems PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 13

Get Book Here

Book Description
An experimental study was conducted to evaluate the pressure drop characteristics of residential duct system components that are either not available or not thoroughly (sometimes incorrectly) described in existing duct design literature. The tests were designed to imitate cases normally found in typical residential and light commercial installations. The study included three different sizes of flexible ducts, under different compression configurations, splitter boxes, supply boots, and a fresh air intake hood. The experimental tests conformed to ASHRAE Standard 120P--''Methods of Testing to Determine Flow Resistance of HVAC Air Ducts and Fittings''. The flexible duct study covered compressibility and bending effects on the total pressure drop, and the results showed that the available published references tend to underestimate the effects of compression in flexible ducts that can increase pressure drops by up to a factor of nine. The supply boots were tested under different configurations including a setup where a flexible duct elbow connection was considered as an integral part of the supply boot. The supply boots results showed that diffusers can increase the pressure drop by up to a factor of two in exit fittings, and the installation configuration can increase the pressure drop by up to a factor of five. The results showed that it is crucial for designers and contractors to be aware of the compressibility effects of the flexible duct, and the installation of supply boots and diffusers.

HVAC Psychrometrics: Understanding and Optimizing Air Conditioning Systems

HVAC Psychrometrics: Understanding and Optimizing Air Conditioning Systems PDF Author: Charles Nehme
Publisher: Charles Nehme
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 39

Get Book Here

Book Description
Air conditioning systems play a crucial role in providing comfortable indoor environments, whether it's in residential, commercial, or industrial settings. Understanding the principles of psychrometrics is essential for designing, operating, and optimizing these HVAC (Heating, Ventilation, and Air Conditioning) systems effectively. Psychrometrics is the study of the thermodynamic properties of air and its moisture content. It involves the measurement and analysis of parameters such as temperature, humidity, pressure, and enthalpy to determine the state of air and its ability to hold moisture. These parameters are crucial for designing air conditioning systems that can maintain optimal indoor conditions for human comfort, equipment operation, and various industrial processes. This book aims to provide a comprehensive understanding of psychrometrics and its practical applications in HVAC systems. It explores the fundamental concepts and equations related to air properties, psychrometric charts, and the psychrometric processes involved in air conditioning. Moreover, it delves into the various components and systems that make up an air conditioning system, such as air handlers, cooling coils, refrigeration cycles, and ventilation systems. Optimizing air conditioning systems is a key focus of this book. By leveraging the principles of psychrometrics, engineers and technicians can enhance the efficiency and performance of HVAC systems, resulting in energy savings, improved indoor air quality, and increased occupant comfort. The book covers topics such as load calculations, equipment selection, airflow distribution, humidity control strategies, and system optimization techniques. Throughout the book, real-world examples, case studies, and practical tips are provided to illustrate the application of psychrometrics in different scenarios. Whether you are a HVAC professional, engineer, technician, or someone interested in understanding the inner workings of air conditioning systems, this book serves as a valuable resource to enhance your knowledge and skills. It is worth noting that while this book provides a comprehensive overview of psychrometrics and air conditioning systems, it does not delve into the intricacies of HVAC design and installation. For detailed design guidelines and standards, it is recommended to refer to relevant industry codes, manuals, and regulations. With a solid understanding of psychrometrics and its role in air conditioning systems, readers will be equipped with the knowledge necessary to design, optimize, and maintain efficient HVAC systems, creating comfortable and healthy indoor environments for all. Let us embark on this journey into the fascinating world of HVAC psychrometrics and unlock the secrets of optimizing air conditioning systems.

Analysis and Design of Heating, Ventilating, and Air-Conditioning Systems, Second Edition

Analysis and Design of Heating, Ventilating, and Air-Conditioning Systems, Second Edition PDF Author: Herbert W. Stanford III
Publisher: CRC Press
ISBN: 0429890877
Category : Science
Languages : en
Pages : 460

Get Book Here

Book Description
Analysis and Design of Heating, Ventilating, and Air-Conditioning Systems, Second Edition, provides a thorough and modern overview of HVAC for commercial and industrial buildings, emphasizing energy efficiency. This text combines coverage of heating and air conditioning systems design with detailed information on the latest controls technologies. It also addresses the art of HVAC design along with carefully explained scientific and technical content, reflecting the extensive experience of the authors. Modern HVAC topics are addressed, including sustainability, IAQ, water treatment and risk management, vibration and noise mitigation, and maintainability from a practical point of view.