Patrick J. Brooks
Senior Project Manager
Chantilly, VA
(513) 767-1000
Region: III
Honorarium: None

Patrick “Pat” Brooks is a Professional Engineer with over 40 years of experience focusing on duct and acoustics design, duct construction and duct fabrication as well as being a general manager and a director of manufacturing.

Pat received his undergraduate degree in Mechanical Engineering in 1978 from The Ohio State University in Columbus Ohio. He received a Master of Science Degree in Mechanical Engineering from the same University in 1986. He also received a Master of Business Administration from The Ohio State University in 1990. He has served as the Manager of Research and Development, General Manager and Director of Manufacturing while at United McGill Corporation. He has also been a General Manager for Eastern Sheet Metal, Inc. and is currently a Senior Project Manager with the Sheet Metal and Air Conditioning Contractors’ National Association, In.c (SMACNA).

As the Manager of the Research and Development department at United McGill, Pat oversaw the development of friction loss and loss coefficients for many types of duct and fittings that are in the ASHRAE Duct Fitting Database, an ASHRAE web-based program used to determine pressure losses that he also helped to develop. He also developed a state-of-the-art duct design program and wrote many technical bulletins and reports. As a General Manager at United McGill and later at Eastern Sheet Metal, he oversaw general operations of the manufacturing and sales of sheet metal ductwork. As Director of Manufacturing he oversaw all manufacturing operations for United McGill including sheet metal ductwork, acoustical panels and silencers, and air pollution control equipment. Now as a Senior Project Manager at SMACNA he helps write and maintain their duct construction, sound and vibration and duct design manuals, as well as write technical papers. He also provides technical support to the Association’s many contractor members. Pat also gives duct construction and other seminars to the sheet metal contractors as well as code officials and engineers. He was also an instructor in duct design and acoustics at the University of Wisconsin.

Pat is an active participant with ASHRAE, SPIDA, AWS and AMCA. He is the ASHRAE Duct Design Guide Chair and Duct Fitting Database Chair and has been a member of the TC5.2 Duct Design committee with over 30 years of service. He is also a member of SPIDA and serves as their technical Chair giving technical support to its members and helping develop research for the round and flat oval spiral duct industry and has given seminars on behave of SPIDA. Pat also is a member of the COVID mitigation committee for AMCA and help develops guidelines for new and existing buildings.He is a committee member of AWS 9.1 Sheet Metal Welding Code.

Pat has published several papers on duct design, duct leakage, acoustics and COVID mitigation including:

09/24/2020 HVAC COVID-19 Guidance SMACANA

12/05/2019 HVAC Duct Air Leakage SMACNA

12/01/2010 ASHRAE Standard 90.1 and Leakage The NEBB Professional

10/01/2007 Industrial Noise Control Occupational Health & Safety

04/01/2001 Designing Industrial Exhaust Systems ASHRAE Journal

04/01/1995 Duct Design Fundamentals ASHRAE Journal

06/18/1990 Computer-aided duct design: Comparing the methods Air Conditioning, Heating & Refrigeration News

Supply Duct Design
This presentation teaches the designer the fundamentals of supply duct design and pressure losses. Friction losses and dynamic losses are covered as well as fitting selection. Duct system layout, use of loss coefficients and friction calculations are shown. Loss coefficient data bases are reviewed. Duct design methods of equal friction, static regain, and total pressure design are explored along with comparisons of each are given. Other topics include how to calculate the initial duct size, reviewing excess pressures in non-design legs, system effect and acoustics. Shapes include round, rectangular and flat oval. How to convert duct from one shape to another using equivalent round diameters is shown.
Exhaust Duct Design
This presentation teaches the designer the fundamentals of exhaust/return duct design and pressure losses. Friction losses and dynamic losses are covered as well as fitting selection. Duct system layout, use of loss coefficients and friction calculations are shown. Loss coefficient data bases are reviewed. Duct design methods for local exhaust systems conveying fumes, dust, particulates, and contaminants from various processes and equal friction are covered. Duct design elements of hood selection to capture pollutants and fume are covered as well as transport conveying velocities are reviewed. Fitting selection and comparison are examined.
Fitting Selection
This presentation teaches the designer the fundamentals of pressure losses. Types of pressure losses, friction losses and dynamic losses are covered. The design leg and non-design legs of the duct design are reviewed for fitting selection. Comparisons of loss coefficients and friction roughness factors are discussed. Loss coefficient data bases are reviewed. Losses for low versus high velocities are discussed. Why using efficient fittings in the initial design is important.
System Effect
This presentation shows how to calculate the system effect caused by different fan inlet and outlet conditions. The design leg and the effects on the system curve are reviewed. How fans are tested will be examined and why fans installed with inlet and outlet ductwork that is different than how it was tested causes the fan to underperform is covered. The designer will learn how to calculate and to solve system effect problems. System Effect Curves and from AMCA will be examined. Using loss coefficients to calculate system effect is also covered.
Duct System Acoustics
This presentation covers the fundamentals of calculating duct system acoustics. The designer will learn what noise is, how to mathematically combine noise levels is and how to control noise in duct systems. Frequency and amplitude and how people perceive noise are important concepts that are also covered. The designer will also learn the difference between sound power and sound pressure and how to convert sound power levels to sound pressure. The range of hearing and the problems with low frequency noise vs high frequency noise is discussed. Natural attenuation of duct elements and how to determine it will be reviewed. How to solve acoustic problems using distance, silencers and duct insertion losses are examined as well as how room criteria (RC) levels are calculated.